Java 21 language features (#4535)

* Java 21 language features

* use getFirst and getLast methods
* replace new Locale by Locale.of
* replace Paths.get by Path.of
* use ThreadLocalRandom.current().nextDouble()
* add @Serial annotations

Signed-off-by: Holger Friedrich <mail@holger-friedrich.de>

bundles/org.openhab.core.addon.marketplace/src/main/java/org/openhab/core/addon/marketplace/MarketplaceBundleInstaller.java

@@ -86,7 +86,7 @@ public abstract class MarketplaceBundleInstaller {
                             "The local cache folder doesn't contain a single file: " + addonPath, null);
                 }
 
-                try (FileInputStream fileInputStream = new FileInputStream(bundleFiles.get(0).toFile())) {
+                try (FileInputStream fileInputStream = new FileInputStream(bundleFiles.getFirst().toFile())) {
                     Bundle bundle = bundleContext.installBundle(addonId, fileInputStream);
                     try {
                         bundle.start();

bundles/org.openhab.core.addon.marketplace/src/main/java/org/openhab/core/addon/marketplace/MarketplaceHandlerException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.addon.marketplace;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class MarketplaceHandlerException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = -5652014141471618161L;
 
     /**

bundles/org.openhab.core.addon.marketplace/src/main/java/org/openhab/core/addon/marketplace/internal/community/SerializedNameAnnotationIntrospector.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.addon.marketplace.internal.community;
 
+import java.io.Serial;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Stream;
@@ -32,6 +33,7 @@ import com.google.gson.annotations.SerializedName;
  */
 @NonNullByDefault
 final class SerializedNameAnnotationIntrospector extends AnnotationIntrospector {
+    @Serial
     private static final long serialVersionUID = 1L;
 
     @Override

bundles/org.openhab.core.addon.marketplace/src/test/java/org/openhab/core/addon/marketplace/AbstractRemoteAddonServiceTest.java

@@ -142,7 +142,7 @@ public class AbstractRemoteAddonServiceTest {
         // check only the installed addon is present
         addons = addonService.getAddons(null);
         assertThat(addons, hasSize(1));
-        assertThat(addons.get(0).getUid(), is(getFullAddonId(TEST_ADDON)));
+        assertThat(addons.getFirst().getUid(), is(getFullAddonId(TEST_ADDON)));
     }
 
     @Test

bundles/org.openhab.core.addon/src/test/java/org/openhab/core/addon/AddonInfoListReaderTest.java

@@ -84,26 +84,26 @@ class AddonInfoListReaderTest {
         assertNotNull(addons);
         List<AddonInfo> addonsInfos = addons.getAddons();
         assertEquals(1, addonsInfos.size());
-        AddonInfo addon = addonsInfos.get(0);
+        AddonInfo addon = addonsInfos.getFirst();
         assertNotNull(addon);
         List<AddonDiscoveryMethod> discoveryMethods = addon.getDiscoveryMethods();
         assertNotNull(discoveryMethods);
         assertEquals(2, discoveryMethods.size());
 
-        AddonDiscoveryMethod method = discoveryMethods.get(0);
+        AddonDiscoveryMethod method = discoveryMethods.getFirst();
         assertNotNull(method);
         assertEquals("mdns", method.getServiceType());
         List<AddonParameter> parameters = method.getParameters();
         assertNotNull(parameters);
         assertEquals(1, parameters.size());
-        AddonParameter parameter = parameters.get(0);
+        AddonParameter parameter = parameters.getFirst();
         assertNotNull(parameter);
         assertEquals("mdnsServiceType", parameter.getName());
         assertEquals("_printer._tcp.local.", parameter.getValue());
         List<AddonMatchProperty> matchProperties = method.getMatchProperties();
         assertNotNull(matchProperties);
         assertEquals(2, matchProperties.size());
-        AddonMatchProperty property = matchProperties.get(0);
+        AddonMatchProperty property = matchProperties.getFirst();
         assertNotNull(property);
         assertEquals("rp", property.getName());
         assertEquals(".*", property.getRegex());
@@ -118,7 +118,7 @@ class AddonInfoListReaderTest {
         matchProperties = method.getMatchProperties();
         assertNotNull(matchProperties);
         assertEquals(1, matchProperties.size());
-        property = matchProperties.get(0);
+        property = matchProperties.getFirst();
         assertNotNull(property);
         assertEquals("modelName", property.getName());
         assertEquals("Philips hue bridge", property.getRegex());

bundles/org.openhab.core.audio/src/main/java/org/openhab/core/audio/AudioException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.audio;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class AudioException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     /**

bundles/org.openhab.core.audio/src/main/java/org/openhab/core/audio/UnsupportedAudioFormatException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.audio;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -25,6 +27,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class UnsupportedAudioFormatException extends AudioException {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     /**

bundles/org.openhab.core.audio/src/main/java/org/openhab/core/audio/UnsupportedAudioStreamException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.audio;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class UnsupportedAudioStreamException extends AudioException {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     /**

bundles/org.openhab.core.audio/src/main/java/org/openhab/core/audio/internal/AudioServlet.java

@@ -17,6 +17,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.io.Serial;
 import java.nio.file.Files;
 import java.util.Collections;
 import java.util.List;
@@ -72,6 +73,7 @@ import org.slf4j.LoggerFactory;
 @NonNullByDefault
 public class AudioServlet extends HttpServlet implements AudioHTTPServer {
 
+    @Serial
     private static final long serialVersionUID = -3364664035854567854L;
 
     private static final List<String> WAV_MIME_TYPES = List.of("audio/wav", "audio/x-wav", "audio/vnd.wave");

bundles/org.openhab.core.automation.module.media/src/main/java/org/openhab/core/automation/module/media/internal/MediaActionTypeProvider.java

@@ -16,7 +16,7 @@ import static java.util.Comparator.comparing;
 
 import java.io.File;
 import java.math.BigDecimal;
-import java.nio.file.Paths;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -138,7 +138,7 @@ public class MediaActionTypeProvider implements ModuleTypeProvider {
      */
     private List<ParameterOption> getSoundOptions() {
         List<ParameterOption> options = new ArrayList<>();
-        File soundsDir = Paths.get(OpenHAB.getConfigFolder(), AudioManager.SOUND_DIR).toFile();
+        File soundsDir = Path.of(OpenHAB.getConfigFolder(), AudioManager.SOUND_DIR).toFile();
         if (soundsDir.isDirectory()) {
             for (String fileName : soundsDir.list()) {
                 if (fileName.contains(".") && !fileName.startsWith(".")) {

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/ScriptEngineFactoryHelper.java

@@ -42,7 +42,7 @@ public class ScriptEngineFactoryHelper {
     public static Map.@Nullable Entry<String, String> getParameterOption(ScriptEngineFactory engineFactory) {
         List<String> scriptTypes = engineFactory.getScriptTypes();
         if (!scriptTypes.isEmpty()) {
-            ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.get(0));
+            ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.getFirst());
             if (scriptEngine != null) {
                 Map.Entry<String, String> parameterOption = Map.entry(getPreferredMimeType(engineFactory),
                         getLanguageName(scriptEngine.getFactory()));
@@ -66,7 +66,7 @@ public class ScriptEngineFactoryHelper {
         }
         List<String> mimeTypes = new ArrayList<>(scriptTypes);
         mimeTypes.removeIf(mimeType -> !mimeType.contains("application") || "application/python".equals(mimeType));
-        return mimeTypes.isEmpty() ? scriptTypes.get(0) : mimeTypes.get(0);
+        return mimeTypes.isEmpty() ? scriptTypes.getFirst() : mimeTypes.getFirst();
     }
 
     public static String getLanguageName(javax.script.ScriptEngineFactory factory) {

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/ScriptEngineManagerImpl.java

@@ -79,7 +79,7 @@ public class ScriptEngineManagerImpl implements ScriptEngineManager {
         }
         if (logger.isDebugEnabled()) {
             if (!scriptTypes.isEmpty()) {
-                ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.get(0));
+                ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.getFirst());
                 if (scriptEngine != null) {
                     javax.script.ScriptEngineFactory factory = scriptEngine.getFactory();
                     logger.debug(

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/handler/AbstractScriptModuleHandler.java

@@ -105,9 +105,9 @@ public abstract class AbstractScriptModuleHandler<T extends Module> extends Base
         Optional<ScriptEngine> engine = getScriptEngine();
         if (engine.isPresent()) {
             ScriptEngine scriptEngine = engine.get();
-            if (scriptEngine instanceof Compilable) {
+            if (scriptEngine instanceof Compilable compilable) {
                 logger.debug("Pre-compiling script of rule with UID '{}'", ruleUID);
-                compiledScript = Optional.ofNullable(((Compilable) scriptEngine).compile(script));
+                compiledScript = Optional.ofNullable(compilable.compile(script));
             }
         }
     }

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/provider/ScriptModuleTypeProvider.java

@@ -161,7 +161,7 @@ public class ScriptModuleTypeProvider extends AbstractProvider<ModuleType> imple
     public void unsetScriptEngineFactory(ScriptEngineFactory engineFactory) {
         List<String> scriptTypes = engineFactory.getScriptTypes();
         if (!scriptTypes.isEmpty()) {
-            ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.get(0));
+            ScriptEngine scriptEngine = engineFactory.createScriptEngine(scriptTypes.getFirst());
             if (scriptEngine != null) {
                 parameterOptions.remove(ScriptEngineFactoryHelper.getPreferredMimeType(engineFactory));
                 logger.trace("ParameterOptions: {}", parameterOptions);

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/commands/AutomationCommandList.java

@@ -126,7 +126,7 @@ public class AutomationCommandList extends AutomationCommand {
             }
             if (getLocale) {
                 String l = parameterValue;
-                locale = new Locale(l);
+                locale = Locale.of(l);
                 getLocale = false;
             }
             if (getId && getLocale) {

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/commands/Printer.java

@@ -339,7 +339,7 @@ public class Printer {
         if (list != null && !list.isEmpty()) {
             for (Object element : list) {
                 if (element instanceof String string) {
-                    res.add(Utils.getColumn(columnWidths[0], values.get(0)) + string);
+                    res.add(Utils.getColumn(columnWidths[0], values.getFirst()) + string);
                     if (isFirst) {
                         isFirst = false;
                         values.set(0, "");
@@ -347,7 +347,7 @@ public class Printer {
                 } else if (element instanceof Module module) {
                     List<String> moduleRecords = getModuleRecords(module);
                     for (String elementRecord : moduleRecords) {
-                        res.add(Utils.getColumn(columnWidths[0], values.get(0)) + elementRecord);
+                        res.add(Utils.getColumn(columnWidths[0], values.getFirst()) + elementRecord);
                         if (isFirst) {
                             isFirst = false;
                             values.set(0, "");

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/module/exception/UncomparableException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.automation.internal.module.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -22,5 +24,6 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class UncomparableException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 4891205711357448390L;
 }

bundles/org.openhab.core.automation/src/test/java/org/openhab/core/automation/internal/module/provider/AnnotationActionModuleTypeProviderTest.java

@@ -196,7 +196,7 @@ public class AnnotationActionModuleTypeProviderTest extends JavaTest {
                 List<ParameterOption> parameterOptions = cdp.getOptions();
                 assertEquals(1, parameterOptions.size());
 
-                ParameterOption po = parameterOptions.get(0);
+                ParameterOption po = parameterOptions.getFirst();
                 assertEquals("conf2", po.getValue());
             }
         }

bundles/org.openhab.core.automation/src/test/java/org/openhab/core/automation/thingsupport/AnnotatedThingActionModuleTypeProviderTest.java

@@ -211,7 +211,7 @@ public class AnnotatedThingActionModuleTypeProviderTest extends JavaTest {
                 List<ParameterOption> parameterOptions = cdp.getOptions();
                 assertEquals(1, parameterOptions.size());
 
-                ParameterOption po = parameterOptions.get(0);
+                ParameterOption po = parameterOptions.getFirst();
                 assertEquals("binding:thing-type:test2", po.getValue());
             }
         }

bundles/org.openhab.core.automation/src/test/java/org/openhab/core/automation/util/ActionInputHelperTest.java

@@ -208,7 +208,7 @@ public class ActionInputHelperTest {
         List<ConfigDescriptionParameter> params = helper
                 .mapActionInputsToConfigDescriptionParameters(List.of(input1, input2));
         assertThat(params.size(), is(2));
-        checkParameter(params.get(0), "Boolean", ConfigDescriptionParameter.Type.BOOLEAN, PARAM_LABEL,
+        checkParameter(params.getFirst(), "Boolean", ConfigDescriptionParameter.Type.BOOLEAN, PARAM_LABEL,
                 PARAM_DESCRIPTION, true, "false", null, null, null);
         checkParameter(params.get(1), "String", ConfigDescriptionParameter.Type.TEXT, PARAM_LABEL, PARAM_DESCRIPTION,
                 false, null, null, null, null);

bundles/org.openhab.core.config.core/src/main/java/org/openhab/core/config/core/ConfigUtil.java

@@ -262,7 +262,7 @@ public class ConfigUtil {
             for (final Object it : collection) {
                 final Object normalized = normalizeType(it, null);
                 lst.add(normalized);
-                if (normalized.getClass() != lst.get(0).getClass()) {
+                if (normalized.getClass() != lst.getFirst().getClass()) {
                     throw new IllegalArgumentException(
                             "Invalid configuration property. Heterogeneous collection value!");
                 }

bundles/org.openhab.core.config.core/src/main/java/org/openhab/core/config/core/validation/ConfigValidationException.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.config.core.validation;
 
+import java.io.Serial;
 import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.Collections;
@@ -35,6 +36,7 @@ import org.slf4j.LoggerFactory;
  */
 public final class ConfigValidationException extends RuntimeException {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     private final Logger logger = LoggerFactory.getLogger(ConfigValidationException.class);

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/ConfigDescriptionBuilderTest.java

@@ -62,7 +62,7 @@ public class ConfigDescriptionBuilderTest {
         assertThat(configDescription.getUID(), is(CONFIG_URI));
         assertThat(configDescription.getParameterGroups(), hasSize(0));
         assertThat(configDescription.getParameters(), hasSize(1));
-        assertThat(configDescription.getParameters().get(0), is(PARAM1));
+        assertThat(configDescription.getParameters().getFirst(), is(PARAM1));
     }
 
     @Test
@@ -81,7 +81,7 @@ public class ConfigDescriptionBuilderTest {
         ConfigDescription configDescription = builder.withParameterGroup(GROUP1).build();
         assertThat(configDescription.getUID(), is(CONFIG_URI));
         assertThat(configDescription.getParameterGroups(), hasSize(1));
-        assertThat(configDescription.getParameterGroups().get(0), is(GROUP1));
+        assertThat(configDescription.getParameterGroups().getFirst(), is(GROUP1));
         assertThat(configDescription.getParameters(), hasSize(0));
     }
 

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/ConfigDescriptionRegistryTest.java

@@ -121,9 +121,9 @@ public class ConfigDescriptionRegistryTest extends JavaTest {
         assertThat(configDescriptionRegistry.getConfigDescriptions().size(), is(1));
 
         List<ConfigDescription> configDescriptions = new ArrayList<>(configDescriptionRegistry.getConfigDescriptions());
-        assertThat(configDescriptions.get(0).getUID(), is(equalTo(uriDummy)));
+        assertThat(configDescriptions.getFirst().getUID(), is(equalTo(uriDummy)));
-        assertThat(configDescriptions.get(0).toParametersMap().size(), is(1));
+        assertThat(configDescriptions.getFirst().toParametersMap().size(), is(1));
-        assertThat(configDescriptions.get(0).toParametersMap().get("param1"), notNullValue());
+        assertThat(configDescriptions.getFirst().toParametersMap().get("param1"), notNullValue());
 
         configDescriptionRegistry.addConfigDescriptionProvider(configDescriptionProviderMock1);
         assertThat(configDescriptionRegistry.getConfigDescriptions().size(), is(2));
@@ -146,11 +146,11 @@ public class ConfigDescriptionRegistryTest extends JavaTest {
         assertThat(configDescriptionRegistry.getConfigDescriptions().size(), is(1));
 
         List<ConfigDescription> configDescriptions = new ArrayList<>(configDescriptionRegistry.getConfigDescriptions());
-        assertThat(configDescriptions.get(0).getUID(), is(equalTo(uriDummy)));
+        assertThat(configDescriptions.getFirst().getUID(), is(equalTo(uriDummy)));
 
-        assertThat(configDescriptions.get(0).getParameters().size(), is(2));
+        assertThat(configDescriptions.getFirst().getParameters().size(), is(2));
-        assertThat(configDescriptions.get(0).getParameters().get(0).getName(), is(equalTo("param1")));
+        assertThat(configDescriptions.getFirst().getParameters().getFirst().getName(), is(equalTo("param1")));
-        assertThat(configDescriptions.get(0).getParameters().get(1).getName(), is(equalTo("param2")));
+        assertThat(configDescriptions.getFirst().getParameters().get(1).getName(), is(equalTo("param2")));
 
         configDescriptionRegistry.removeConfigDescriptionProvider(configDescriptionProviderMock);
         assertThat(configDescriptionRegistry.getConfigDescriptions().size(), is(1));
@@ -168,8 +168,8 @@ public class ConfigDescriptionRegistryTest extends JavaTest {
         configDescriptionRegistry.addConfigOptionProvider(configOptionsProviderMockAliased);
 
         ConfigDescription res = requireNonNull(configDescriptionRegistry.getConfigDescription(uriAliases));
-        assertThat(res.getParameters().get(0).getOptions().size(), is(1));
+        assertThat(res.getParameters().getFirst().getOptions().size(), is(1));
-        assertThat(res.getParameters().get(0).getOptions().get(0).getLabel(), is("Aliased"));
+        assertThat(res.getParameters().getFirst().getOptions().getFirst().getLabel(), is("Aliased"));
         assertThat(res.getUID(), is(uriAliases));
 
         configDescriptionRegistry.removeConfigDescriptionProvider(configDescriptionProviderMock);
@@ -186,8 +186,8 @@ public class ConfigDescriptionRegistryTest extends JavaTest {
         configDescriptionRegistry.addConfigOptionProvider(configOptionsProviderMockAliased);
 
         ConfigDescription res = requireNonNull(configDescriptionRegistry.getConfigDescription(uriAliases));
-        assertThat(res.getParameters().get(0).getOptions().size(), is(1));
+        assertThat(res.getParameters().getFirst().getOptions().size(), is(1));
-        assertThat(res.getParameters().get(0).getOptions().get(0).getLabel(), is("Aliased"));
+        assertThat(res.getParameters().getFirst().getOptions().getFirst().getLabel(), is("Aliased"));
         assertThat(res.getUID(), is(uriAliases));
 
         configDescriptionRegistry.removeConfigDescriptionProvider(configDescriptionProviderMock);
@@ -203,8 +203,8 @@ public class ConfigDescriptionRegistryTest extends JavaTest {
         configDescriptionRegistry.addConfigOptionProvider(configOptionsProviderMock);
 
         ConfigDescription res = requireNonNull(configDescriptionRegistry.getConfigDescription(uriAliases));
-        assertThat(res.getParameters().get(0).getOptions().size(), is(1));
+        assertThat(res.getParameters().getFirst().getOptions().size(), is(1));
-        assertThat(res.getParameters().get(0).getOptions().get(0).getLabel(), is("Original"));
+        assertThat(res.getParameters().getFirst().getOptions().getFirst().getLabel(), is("Original"));
         assertThat(res.getUID(), is(uriAliases));
 
         configDescriptionRegistry.removeConfigDescriptionProvider(configDescriptionProviderMock);

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/ConfigurationTest.java

@@ -119,7 +119,7 @@ public class ConfigurationTest {
         configuration.put("stringField", "someValue");
         configuration.put("additionalField", "");
         assertThat(props.get("stringField"), is(nullValue()));
-        assertThat(values.get(0), is(nullValue()));
+        assertThat(values.getFirst(), is(nullValue()));
         assertThat(values.get(1), is(nullValue()));
         assertThat(values.size(), is(2));
         assertThat(keys.size(), is(2));

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/dto/ConfigDescriptionDTOTest.java

@@ -85,7 +85,7 @@ class ConfigDescriptionDTOTest {
                 .map(ConfigDescriptionDTOMapper.mapParameters(subject));
         assertThat(result, hasSize(1));
 
-        ConfigDescriptionParameter parameter = result.get(0);
+        ConfigDescriptionParameter parameter = result.getFirst();
         assertThat(parameter.getName(), is(PARAM_NAME));
         assertThat(parameter.getType(), is(Type.INTEGER));
         assertThat(parameter.isAdvanced(), is(true));
@@ -120,7 +120,7 @@ class ConfigDescriptionDTOTest {
                 .mapParameterGroupsDTO(ConfigDescriptionDTOMapper.mapParameterGroups(subject));
         assertThat(result, hasSize(1));
 
-        ConfigDescriptionParameterGroup parameterGroup = result.get(0);
+        ConfigDescriptionParameterGroup parameterGroup = result.getFirst();
         assertThat(parameterGroup.getName(), is(PARAMETER_GROUP_NAME));
         assertThat(parameterGroup.isAdvanced(), is(true));
         assertThat(parameterGroup.getContext(), is(PARAMETER_GROUP_CONTEXT));

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/internal/metadata/MetadataConfigDescriptionProviderImplTest.java

@@ -92,7 +92,7 @@ public class MetadataConfigDescriptionProviderImplTest extends JavaTest {
         assertEquals(URI_LIBERAL, desc.getUID());
         assertEquals(1, desc.getParameters().size());
 
-        ConfigDescriptionParameter param = desc.getParameters().get(0);
+        ConfigDescriptionParameter param = desc.getParameters().getFirst();
         assertEquals("value", param.getName());
         assertEquals("Liberal", param.getDescription());
         assertFalse(param.getLimitToOptions());
@@ -110,11 +110,11 @@ public class MetadataConfigDescriptionProviderImplTest extends JavaTest {
         assertEquals(URI_RESTRICTED, desc.getUID());
         assertEquals(1, desc.getParameters().size());
 
-        ConfigDescriptionParameter param = desc.getParameters().get(0);
+        ConfigDescriptionParameter param = desc.getParameters().getFirst();
         assertEquals("value", param.getName());
         assertEquals("Restricted", param.getDescription());
         assertTrue(param.getLimitToOptions());
-        assertEquals("dimmer", param.getOptions().get(0).getValue());
+        assertEquals("dimmer", param.getOptions().getFirst().getValue());
         assertEquals("switch", param.getOptions().get(1).getValue());
     }
 
@@ -136,7 +136,7 @@ public class MetadataConfigDescriptionProviderImplTest extends JavaTest {
         assertEquals(URI_LIBERAL, desc.getUID());
         assertEquals(1, desc.getParameters().size());
 
-        ConfigDescriptionParameter param = desc.getParameters().get(0);
+        ConfigDescriptionParameter param = desc.getParameters().getFirst();
         assertEquals("value", param.getName());
         assertEquals("Liberal", param.getDescription());
         assertFalse(param.getLimitToOptions());
@@ -161,7 +161,7 @@ public class MetadataConfigDescriptionProviderImplTest extends JavaTest {
         assertEquals(URI_RESTRICTED_DIMMER, desc.getUID());
         assertEquals(2, desc.getParameters().size());
 
-        ConfigDescriptionParameter paramWidth = desc.getParameters().get(0);
+        ConfigDescriptionParameter paramWidth = desc.getParameters().getFirst();
         assertEquals("width", paramWidth.getName());
 
         ConfigDescriptionParameter paramHeight = desc.getParameters().get(1);

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/core/status/ConfigStatusServiceTest.java

@@ -47,8 +47,8 @@ public class ConfigStatusServiceTest extends JavaTest {
     private static final String ENTITY_ID1 = "entity1";
     private static final String ENTITY_ID2 = "entity2";
 
-    private static final Locale LOCALE_DE = new Locale("de");
+    private static final Locale LOCALE_DE = Locale.of("de");
-    private static final Locale LOCALE_EN = new Locale("en");
+    private static final Locale LOCALE_EN = Locale.of("en");
 
     private static final String PARAM1 = "param1";
     private static final String PARAM2 = "param2";
@@ -108,7 +108,7 @@ public class ConfigStatusServiceTest extends JavaTest {
                 MessageFormat.format(MSG3_EN, ARGS), PARAM3_MSG3.statusCode));
 
         LocaleProvider localeProvider = mock(LocaleProvider.class);
-        when(localeProvider.getLocale()).thenReturn(new Locale("en", "US"));
+        when(localeProvider.getLocale()).thenReturn(Locale.of("en", "US"));
 
         configStatusService = new ConfigStatusService(mock(EventPublisher.class), localeProvider,
                 getTranslationProvider(), mock(BundleResolver.class));

bundles/org.openhab.core.config.core/src/test/java/org/openhab/core/config/xml/util/XmlDocumentReaderTest.java

@@ -88,17 +88,18 @@ public class XmlDocumentReaderTest {
      */
     @Test
     public void defaultSecurityProtectsAgainstRemoteCodeExecution() throws Exception {
-        String xml = "<contact class='dynamic-proxy'>\n" //
+        String xml = """
-                + "  <interface>org.openhab.core.Contact</interface>\n"
+                <contact class='dynamic-proxy'>
-                + "  <handler class='java.beans.EventHandler'>\n" //
+                  <interface>org.openhab.core.Contact</interface>
-                + "    <target class='java.lang.ProcessBuilder'>\n" //
+                  <handler class='java.beans.EventHandler'>
-                + "      <command>\n" //
+                    <target class='java.lang.ProcessBuilder'>
-                + "        <string>calc.exe</string>\n" //
+                      <command>
-                + "      </command>\n" //
+                        <string>calc.exe</string>
-                + "    </target>\n" //
+                      </command>
-                + "    <action>start</action>\n" //
+                    </target>
-                + "  </handler>\n" //
+                    <action>start</action>
-                + "</contact>";
+                  </handler>
+                </contact>""";
 
         assertThrows(ForbiddenClassException.class, () -> readXML(xml));
     }

bundles/org.openhab.core.config.discovery.addon.upnp/src/test/java/org/openhab/core/config/discovery/addon/upnp/tests/UpnpAddonFinderTests.java

@@ -114,7 +114,7 @@ public class UpnpAddonFinderTests {
         assertNotNull(upnpService);
         List<RemoteDevice> result = new ArrayList<>(upnpService.getRegistry().getRemoteDevices());
         assertEquals(1, result.size());
-        RemoteDevice device = result.get(0);
+        RemoteDevice device = result.getFirst();
         assertEquals("manufacturer", device.getDetails().getManufacturerDetails().getManufacturer());
         assertEquals("serialNumber", device.getDetails().getSerialNumber());
     }

bundles/org.openhab.core.config.discovery.sddp/src/main/java/org/openhab/core/config/discovery/sddp/SddpDiscoveryService.java

@@ -159,7 +159,7 @@ public class SddpDiscoveryService extends AbstractDiscoveryService
         if (!data.isBlank()) {
             List<String> lines = data.lines().toList();
             if (lines.size() > 1) {
-                String statement = lines.get(0).strip();
+                String statement = lines.getFirst().strip();
                 boolean offline = statement.startsWith(NOTIFY_OFFLINE_HEADER);
                 if (offline || statement.startsWith(NOTIFY_ALIVE_HEADER) || statement.startsWith(NOTIFY_IDENTIFY_HEADER)
                         || statement.startsWith(SEARCH_RESPONSE_HEADER)) {

bundles/org.openhab.core.config.discovery.usbserial.linuxsysfs/src/main/java/org/openhab/core/config/discovery/usbserial/linuxsysfs/internal/SysfsUsbSerialScanner.java

@@ -18,7 +18,6 @@ import java.io.IOException;
 import java.nio.file.DirectoryStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Objects;
@@ -127,7 +126,7 @@ public class SysfsUsbSerialScanner implements UsbSerialScanner {
 
     @Override
     public boolean canPerformScans() {
-        return isReadable(Paths.get(sysfsTtyDevicesDirectory)) && isReadable(Paths.get(devDirectory));
+        return isReadable(Path.of(sysfsTtyDevicesDirectory)) && isReadable(Path.of(devDirectory));
     }
 
     /**
@@ -140,10 +139,10 @@ public class SysfsUsbSerialScanner implements UsbSerialScanner {
     private Set<SerialPortInfo> getSerialPortInfos() throws IOException {
         Set<SerialPortInfo> result = new HashSet<>();
 
-        try (DirectoryStream<Path> sysfsTtyPaths = newDirectoryStream(Paths.get(sysfsTtyDevicesDirectory))) {
+        try (DirectoryStream<Path> sysfsTtyPaths = newDirectoryStream(Path.of(sysfsTtyDevicesDirectory))) {
             for (Path sysfsTtyPath : sysfsTtyPaths) {
                 String serialPortName = sysfsTtyPath.getFileName().toString();
-                Path devicePath = Paths.get(devDirectory).resolve(serialPortName);
+                Path devicePath = Path.of(devDirectory).resolve(serialPortName);
                 Path sysfsDevicePath = getRealDevicePath(sysfsTtyPath);
                 if (sysfsDevicePath != null && isReadable(devicePath) && isWritable(devicePath)) {
                     result.add(new SerialPortInfo(devicePath, sysfsDevicePath));
@@ -163,7 +162,7 @@ public class SysfsUsbSerialScanner implements UsbSerialScanner {
                             String serialPortName = devicePath.getFileName().toString();
                             // get the corresponding real sysinfo special dir :
                             Path sysfsDevicePath = getRealDevicePath(
-                                    Paths.get(sysfsTtyDevicesDirectory).resolve(serialPortName));
+                                    Path.of(sysfsTtyDevicesDirectory).resolve(serialPortName));
                             if (sysfsDevicePath != null && isReadable(devicePath) && isWritable(devicePath)) {
                                 result.add(new SerialPortInfo(devLinkPath, sysfsDevicePath));
                             }

bundles/org.openhab.core.config.discovery/src/main/java/org/openhab/core/config/discovery/internal/AutomaticInboxProcessor.java

@@ -217,7 +217,7 @@ public class AutomaticInboxProcessor extends AbstractTypedEventSubscriber<ThingS
         if (results.size() == 1) {
             logger.debug("Auto-ignoring the inbox entry for the representation value '{}'.", representationValue);
 
-            inbox.setFlag(results.get(0).getThingUID(), DiscoveryResultFlag.IGNORED);
+            inbox.setFlag(results.getFirst().getThingUID(), DiscoveryResultFlag.IGNORED);
         }
     }
 
@@ -255,7 +255,7 @@ public class AutomaticInboxProcessor extends AbstractTypedEventSubscriber<ThingS
         if (results.size() == 1) {
             logger.debug("Removing the ignored result from the inbox for the representation value '{}'.",
                     representationValue);
-            inbox.remove(results.get(0).getThingUID());
+            inbox.remove(results.getFirst().getThingUID());
         }
     }
 

bundles/org.openhab.core.config.discovery/src/main/java/org/openhab/core/config/discovery/internal/PersistentInbox.java

@@ -192,7 +192,7 @@ public final class PersistentInbox implements Inbox, DiscoveryListener, ThingReg
         if (newThingId != null && newThingId.contains(AbstractUID.SEPARATOR)) {
             throw new IllegalArgumentException("New Thing ID " + newThingId + " must not contain multiple segments");
         }
-        DiscoveryResult result = results.get(0);
+        DiscoveryResult result = results.getFirst();
         final Map<String, String> properties = new HashMap<>();
         final Map<String, Object> configParams = new HashMap<>();
         getPropsAndConfigParams(result, properties, configParams);

bundles/org.openhab.core.config.discovery/src/main/java/org/openhab/core/config/discovery/internal/console/DiscoveryConsoleCommandExtension.java

@@ -102,7 +102,7 @@ public class DiscoveryConsoleCommandExtension extends AbstractConsoleCommandExte
                     break;
             }
         } else {
-            console.println(getUsages().get(0));
+            console.println(getUsages().getFirst());
         }
     }
 

bundles/org.openhab.core.config.discovery/src/test/java/org/openhab/core/config/discovery/inbox/InboxPredicatesTest.java

@@ -81,7 +81,7 @@ public class InboxPredicatesTest {
         assertThat(RESULTS.stream().filter(forBinding(BINDING_ID1)).toList().size(), is(3));
 
         assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).toList().get(0), is(equalTo(RESULTS.get(3))));
+        assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).toList().getFirst(), is(equalTo(RESULTS.get(3))));
 
         assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).filter(withFlag(DiscoveryResultFlag.NEW)).toList()
                 .size(), is(0));
@@ -89,7 +89,7 @@ public class InboxPredicatesTest {
         assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).filter(withFlag(DiscoveryResultFlag.IGNORED))
                 .toList().size(), is(1));
         assertThat(RESULTS.stream().filter(forBinding(BINDING_ID2)).filter(withFlag(DiscoveryResultFlag.IGNORED))
-                .toList().get(0), is(equalTo(RESULTS.get(3))));
+                .toList().getFirst(), is(equalTo(RESULTS.get(3))));
     }
 
     @Test
@@ -97,27 +97,28 @@ public class InboxPredicatesTest {
         assertThat(RESULTS.stream().filter(forThingTypeUID(THING_TYPE_UID11)).toList().size(), is(2));
 
         assertThat(RESULTS.stream().filter(forThingTypeUID(THING_TYPE_UID12)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(forThingTypeUID(THING_TYPE_UID12)).toList().get(0),
+        assertThat(RESULTS.stream().filter(forThingTypeUID(THING_TYPE_UID12)).toList().getFirst(),
                 is(equalTo(RESULTS.get(2))));
     }
 
     @Test
     public void testForThingUID() {
         assertThat(RESULTS.stream().filter(forThingUID(THING_UID11)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(forThingUID(THING_UID11)).toList().get(0), is(equalTo(RESULTS.get(0))));
+        assertThat(RESULTS.stream().filter(forThingUID(THING_UID11)).toList().getFirst(),
+                is(equalTo(RESULTS.getFirst())));
 
         assertThat(RESULTS.stream().filter(forThingUID(THING_UID12)).toList().size(), is(2));
         assertThat(RESULTS.stream().filter(forThingUID(THING_UID12)).filter(forThingTypeUID(THING_TYPE_UID12)).toList()
                 .size(), is(1));
         assertThat(RESULTS.stream().filter(forThingUID(THING_UID12)).filter(forThingTypeUID(THING_TYPE_UID12)).toList()
-                .get(0), is(equalTo(RESULTS.get(2))));
+                .getFirst(), is(equalTo(RESULTS.get(2))));
     }
 
     @Test
     public void testWithFlag() {
         assertThat(RESULTS.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList().size(), is(3));
         assertThat(RESULTS.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList().get(0),
+        assertThat(RESULTS.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList().getFirst(),
                 is(equalTo(RESULTS.get(3))));
     }
 
@@ -133,20 +134,20 @@ public class InboxPredicatesTest {
     @Test
     public void testWithRepresentationProperty() {
         assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP1)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP1)).toList().get(0),
+        assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP1)).toList().getFirst(),
-                is(equalTo(RESULTS.get(0))));
+                is(equalTo(RESULTS.getFirst())));
         assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP2)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP2)).toList().get(0),
+        assertThat(RESULTS.stream().filter(withRepresentationProperty(PROP2)).toList().getFirst(),
                 is(equalTo(RESULTS.get(2))));
     }
 
     @Test
     public void testWithRepresentationPropertyValue() {
         assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL1)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL1)).toList().get(0),
+        assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL1)).toList().getFirst(),
-                is(equalTo(RESULTS.get(0))));
+                is(equalTo(RESULTS.getFirst())));
         assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL2)).toList().size(), is(1));
-        assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL2)).toList().get(0),
+        assertThat(RESULTS.stream().filter(withRepresentationPropertyValue(PROP_VAL2)).toList().getFirst(),
                 is(equalTo(RESULTS.get(2))));
     }
 }

bundles/org.openhab.core.config.discovery/src/test/java/org/openhab/core/config/discovery/internal/AutomaticInboxProcessorTest.java

@@ -168,7 +168,7 @@ public class AutomaticInboxProcessorTest {
         // Then there is a discovery result which is NEW
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
 
         // Now a thing with thing type THING_TYPE_UID3 goes online, with representation property value being also the
         // device id
@@ -181,7 +181,7 @@ public class AutomaticInboxProcessorTest {
         // Then there should still be the NEW discovery result, but no IGNORED discovery result
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(0));
     }
@@ -203,7 +203,7 @@ public class AutomaticInboxProcessorTest {
         // Then there is a discovery result which is NEW
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID3)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID3)));
     }
 
     @Test
@@ -213,7 +213,7 @@ public class AutomaticInboxProcessorTest {
 
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
 
         when(thingRegistryMock.get(THING_UID)).thenReturn(thingMock);
         when(thingStatusInfoChangedEventMock.getStatusInfo())
@@ -225,7 +225,7 @@ public class AutomaticInboxProcessorTest {
         assertThat(results.size(), is(0));
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
     }
 
     @Test
@@ -239,7 +239,7 @@ public class AutomaticInboxProcessorTest {
         inbox.add(DiscoveryResultBuilder.create(THING_UID).withProperty(DEVICE_ID_KEY, DEVICE_ID).build());
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
 
         when(thingMock.getProperties()).thenReturn(Map.of());
         when(thingStatusInfoChangedEventMock.getStatusInfo())
@@ -266,7 +266,7 @@ public class AutomaticInboxProcessorTest {
         assertThat(results.size(), is(0));
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID2)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID2)));
     }
 
     @Test
@@ -277,7 +277,7 @@ public class AutomaticInboxProcessorTest {
         inbox.setFlag(THING_UID, DiscoveryResultFlag.IGNORED);
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
 
         automaticInboxProcessor.removed(thingMock);
 
@@ -302,7 +302,7 @@ public class AutomaticInboxProcessorTest {
 
         results = inbox.getAll();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID3)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID3)));
     }
 
     @Test
@@ -312,7 +312,7 @@ public class AutomaticInboxProcessorTest {
 
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.NEW)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID2)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID2)));
 
         when(thingRegistryMock.get(THING_UID2)).thenReturn(thing2Mock);
         when(thingStatusInfoChangedEventMock.getStatusInfo())
@@ -324,7 +324,7 @@ public class AutomaticInboxProcessorTest {
         assertThat(results.size(), is(0));
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID2)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID2)));
     }
 
     @Test
@@ -342,7 +342,7 @@ public class AutomaticInboxProcessorTest {
         assertThat(results.size(), is(0));
         results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID)));
     }
 
     @Test
@@ -353,7 +353,7 @@ public class AutomaticInboxProcessorTest {
         inbox.setFlag(THING_UID2, DiscoveryResultFlag.IGNORED);
         List<DiscoveryResult> results = inbox.stream().filter(withFlag(DiscoveryResultFlag.IGNORED)).toList();
         assertThat(results.size(), is(1));
-        assertThat(results.get(0).getThingUID(), is(equalTo(THING_UID2)));
+        assertThat(results.getFirst().getThingUID(), is(equalTo(THING_UID2)));
 
         automaticInboxProcessor.removed(thing2Mock);
 

bundles/org.openhab.core.config.dispatch/src/main/java/org/openhab/core/config/dispatch/internal/ConfigDispatcher.java

@@ -294,7 +294,7 @@ public class ConfigDispatcher {
 
         // configuration file contains a PID Marker
         List<String> lines = Files.readAllLines(configFile.toPath(), StandardCharsets.UTF_8);
-        String exclusivePID = !lines.isEmpty() ? getPIDFromLine(lines.get(0)) : null;
+        String exclusivePID = !lines.isEmpty() ? getPIDFromLine(lines.getFirst()) : null;
         if (exclusivePID != null) {
             if (exclusivePIDMap.contains(exclusivePID)) {
                 logger.warn(

bundles/org.openhab.core.id/src/test/java/org/openhab/core/id/InstanceUUIDTest.java

@@ -17,7 +17,6 @@ import static org.junit.jupiter.api.Assertions.*;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.junit.jupiter.api.Test;
@@ -41,7 +40,7 @@ public class InstanceUUIDTest {
     public void readFromPersistedFile() throws IOException {
         // we first need to remove the cached value
         InstanceUUID.uuid = null;
-        Path path = Paths.get(OpenHAB.getUserDataFolder(), InstanceUUID.UUID_FILE_NAME);
+        Path path = Path.of(OpenHAB.getUserDataFolder(), InstanceUUID.UUID_FILE_NAME);
         Files.createDirectories(path.getParent());
         Files.write(path, "123".getBytes());
         String uuid = InstanceUUID.get();
@@ -52,7 +51,7 @@ public class InstanceUUIDTest {
     public void ignoreEmptyFile() throws IOException {
         // we first need to remove the cached value
         InstanceUUID.uuid = null;
-        Path path = Paths.get(OpenHAB.getUserDataFolder(), InstanceUUID.UUID_FILE_NAME);
+        Path path = Path.of(OpenHAB.getUserDataFolder(), InstanceUUID.UUID_FILE_NAME);
         Files.createDirectories(path.getParent());
         Files.write(path, "".getBytes());
         String uuid = InstanceUUID.get();

bundles/org.openhab.core.io.bin2json/src/main/java/org/openhab/core/io/bin2json/ConversionException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.bin2json;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -22,6 +24,7 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class ConversionException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     public ConversionException() {

bundles/org.openhab.core.io.console.karaf/src/test/java/org/openhab/core/io/console/karaf/internal/CompleterWrapperTest.java

@@ -61,8 +61,8 @@ public class CompleterWrapperTest {
 
         completerWrapper.completeCandidates(session, commandLine, candidates);
         assertEquals(1, candidates.size());
-        assertEquals("command", candidates.get(0).value());
+        assertEquals("command", candidates.getFirst().value());
-        assertEquals("description", candidates.get(0).descr());
+        assertEquals("description", candidates.getFirst().descr());
     }
 
     @Test
@@ -75,8 +75,8 @@ public class CompleterWrapperTest {
 
         completerWrapper.completeCandidates(session, commandLine, candidates);
         assertEquals(2, candidates.size());
-        assertEquals("command", candidates.get(0).value());
+        assertEquals("command", candidates.getFirst().value());
-        assertEquals("description", candidates.get(0).descr());
+        assertEquals("description", candidates.getFirst().descr());
 
         assertEquals("openhab:command", candidates.get(1).value());
         assertEquals("description", candidates.get(1).descr());

bundles/org.openhab.core.io.console/src/test/java/org/openhab/core/io/console/StringsCompleterTest.java

@@ -33,7 +33,7 @@ public class StringsCompleterTest {
         // positive match
         assertTrue(sc.complete(new String[] { "a" }, 0, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("abc ", candidates.get(0));
+        assertEquals("abc ", candidates.getFirst());
         candidates.clear();
 
         // negative match
@@ -43,25 +43,25 @@ public class StringsCompleterTest {
         // case insensitive
         assertTrue(sc.complete(new String[] { "A" }, 0, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("abc ", candidates.get(0));
+        assertEquals("abc ", candidates.getFirst());
         candidates.clear();
 
         // second argument
         assertTrue(sc.complete(new String[] { "a", "d" }, 1, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("def ", candidates.get(0));
+        assertEquals("def ", candidates.getFirst());
         candidates.clear();
 
         // cursor not at end of word (truncates rest)
         assertTrue(sc.complete(new String[] { "a", "dg" }, 1, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("def ", candidates.get(0));
+        assertEquals("def ", candidates.getFirst());
         candidates.clear();
 
         // first argument when second is present
         assertTrue(sc.complete(new String[] { "a", "d" }, 0, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("abc ", candidates.get(0));
+        assertEquals("abc ", candidates.getFirst());
     }
 
     @Test
@@ -77,7 +77,7 @@ public class StringsCompleterTest {
 
         assertTrue(sc.complete(new String[] { "AB" }, 0, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("ABc ", candidates.get(0));
+        assertEquals("ABc ", candidates.getFirst());
     }
 
     @Test
@@ -87,7 +87,7 @@ public class StringsCompleterTest {
 
         assertTrue(sc.complete(new String[] { "abcd" }, 0, 4, candidates));
         assertEquals(5, candidates.size());
-        assertEquals("abcdd ", candidates.get(0));
+        assertEquals("abcdd ", candidates.getFirst());
         assertEquals("abcde ", candidates.get(1));
         assertEquals("abcdee ", candidates.get(2));
         assertEquals("abcdef ", candidates.get(3));
@@ -96,13 +96,13 @@ public class StringsCompleterTest {
 
         assertTrue(sc.complete(new String[] { "abcde" }, 0, 5, candidates));
         assertEquals(3, candidates.size());
-        assertEquals("abcde ", candidates.get(0));
+        assertEquals("abcde ", candidates.getFirst());
         assertEquals("abcdee ", candidates.get(1));
         assertEquals("abcdef ", candidates.get(2));
         candidates.clear();
 
         assertTrue(sc.complete(new String[] { "abcdee" }, 0, 6, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("abcdee ", candidates.get(0));
+        assertEquals("abcdee ", candidates.getFirst());
     }
 }

bundles/org.openhab.core.io.console/src/test/java/org/openhab/core/io/console/internal/extension/ItemConsoleCommandCompleterTest.java

@@ -63,13 +63,13 @@ public class ItemConsoleCommandCompleterTest {
 
         assertTrue(completer.complete(new String[] { "It" }, 0, 2, candidates));
         assertEquals(2, candidates.size());
-        assertEquals("Item1 ", candidates.get(0));
+        assertEquals("Item1 ", candidates.getFirst());
         assertEquals("Item2 ", candidates.get(1));
         candidates.clear();
 
         assertTrue(completer.complete(new String[] { "JI" }, 0, 2, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("JItem1 ", candidates.get(0));
+        assertEquals("JItem1 ", candidates.getFirst());
         candidates.clear();
 
         // case sensitive
@@ -98,7 +98,7 @@ public class ItemConsoleCommandCompleterTest {
 
         assertTrue(completer.complete(new String[] { "Item1", "" }, 1, 0, candidates));
         assertEquals(3, candidates.size());
-        assertEquals("OFF ", candidates.get(0));
+        assertEquals("OFF ", candidates.getFirst());
         assertEquals("ON ", candidates.get(1));
         assertEquals("REFRESH ", candidates.get(2));
         candidates.clear();
@@ -106,7 +106,7 @@ public class ItemConsoleCommandCompleterTest {
         // case insensitive
         assertTrue(completer.complete(new String[] { "Item1", "o" }, 1, 1, candidates));
         assertEquals(2, candidates.size());
-        assertEquals("OFF ", candidates.get(0));
+        assertEquals("OFF ", candidates.getFirst());
         assertEquals("ON ", candidates.get(1));
     }
 
@@ -123,7 +123,7 @@ public class ItemConsoleCommandCompleterTest {
 
         assertTrue(completer.complete(new String[] { "Item1", "" }, 1, 0, candidates));
         assertEquals(4, candidates.size());
-        assertEquals("NULL ", candidates.get(0));
+        assertEquals("NULL ", candidates.getFirst());
         assertEquals("OFF ", candidates.get(1));
         assertEquals("ON ", candidates.get(2));
         assertEquals("UNDEF ", candidates.get(3));
@@ -132,7 +132,7 @@ public class ItemConsoleCommandCompleterTest {
         // case insensitive
         assertTrue(completer.complete(new String[] { "Item1", "o" }, 1, 1, candidates));
         assertEquals(2, candidates.size());
-        assertEquals("OFF ", candidates.get(0));
+        assertEquals("OFF ", candidates.getFirst());
         assertEquals("ON ", candidates.get(1));
     }
 }

bundles/org.openhab.core.io.console/src/test/java/org/openhab/core/io/console/internal/extension/ItemConsoleCommandExtensionTest.java

@@ -52,7 +52,7 @@ public class ItemConsoleCommandExtensionTest {
 
         assertTrue(completer.complete(new String[] { "" }, 0, 0, candidates));
         assertEquals(5, candidates.size());
-        assertEquals("addTag ", candidates.get(0));
+        assertEquals("addTag ", candidates.getFirst());
         assertEquals("clear ", candidates.get(1));
         assertEquals("list ", candidates.get(2));
         assertEquals("remove ", candidates.get(3));
@@ -61,7 +61,7 @@ public class ItemConsoleCommandExtensionTest {
 
         assertTrue(completer.complete(new String[] { "A", "Item1" }, 0, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("addTag ", candidates.get(0));
+        assertEquals("addTag ", candidates.getFirst());
     }
 
     @Test
@@ -75,17 +75,17 @@ public class ItemConsoleCommandExtensionTest {
 
         assertTrue(completer.complete(new String[] { "addTag", "I" }, 0, 6, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("addTag ", candidates.get(0));
+        assertEquals("addTag ", candidates.getFirst());
         candidates.clear();
 
         assertTrue(completer.complete(new String[] { "addTag", "I" }, 1, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("Item1 ", candidates.get(0));
+        assertEquals("Item1 ", candidates.getFirst());
         candidates.clear();
 
         assertTrue(completer.complete(new String[] { "rmTag", "I" }, 1, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("Item1 ", candidates.get(0));
+        assertEquals("Item1 ", candidates.getFirst());
     }
 
     @Test
@@ -96,12 +96,12 @@ public class ItemConsoleCommandExtensionTest {
 
         assertTrue(completer.complete(new String[] { "remove", "I" }, 0, 6, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("remove ", candidates.get(0));
+        assertEquals("remove ", candidates.getFirst());
         candidates.clear();
 
         assertTrue(completer.complete(new String[] { "remove", "I" }, 1, 1, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("Item2 ", candidates.get(0));
+        assertEquals("Item2 ", candidates.getFirst());
     }
 
     @Test
@@ -135,6 +135,6 @@ public class ItemConsoleCommandExtensionTest {
 
         assertTrue(completer.complete(new String[] { "rmTag", "Item3", "" }, 2, 0, candidates));
         assertEquals(1, candidates.size());
-        assertEquals("Tag1 ", candidates.get(0));
+        assertEquals("Tag1 ", candidates.getFirst());
     }
 }

bundles/org.openhab.core.io.http.auth/src/main/java/org/openhab/core/io/http/auth/internal/AbstractAuthPageServlet.java

@@ -14,6 +14,7 @@ package org.openhab.core.io.http.auth.internal;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.Serial;
 import java.io.UncheckedIOException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -51,6 +52,7 @@ import org.slf4j.LoggerFactory;
 @NonNullByDefault
 public abstract class AbstractAuthPageServlet extends HttpServlet {
 
+    @Serial
     private static final long serialVersionUID = 5340598701104679840L;
 
     private static final String MESSAGES_BUNDLE_NAME = "messages";

bundles/org.openhab.core.io.http.auth/src/main/java/org/openhab/core/io/http/auth/internal/AuthorizePageServlet.java

@@ -13,6 +13,7 @@
 package org.openhab.core.io.http.auth.internal;
 
 import java.io.IOException;
+import java.io.Serial;
 import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
@@ -62,6 +63,7 @@ public class AuthorizePageServlet extends AbstractAuthPageServlet {
 
     public static final String SERVLET_PATH = "/auth";
 
+    @Serial
     private static final long serialVersionUID = 5340598701104679843L;
 
     private final Logger logger = LoggerFactory.getLogger(AuthorizePageServlet.class);

bundles/org.openhab.core.io.http.auth/src/main/java/org/openhab/core/io/http/auth/internal/ChangePasswordPageServlet.java

@@ -13,6 +13,7 @@
 package org.openhab.core.io.http.auth.internal;
 
 import java.io.IOException;
+import java.io.Serial;
 import java.util.Map;
 
 import javax.servlet.Servlet;
@@ -48,6 +49,7 @@ public class ChangePasswordPageServlet extends AbstractAuthPageServlet {
 
     public static final String SERVLET_PATH = "/changePassword";
 
+    @Serial
     private static final long serialVersionUID = 5340598701104679843L;
 
     @Activate

bundles/org.openhab.core.io.http.auth/src/main/java/org/openhab/core/io/http/auth/internal/CreateAPITokenPageServlet.java

@@ -13,6 +13,7 @@
 package org.openhab.core.io.http.auth.internal;
 
 import java.io.IOException;
+import java.io.Serial;
 import java.util.Map;
 
 import javax.servlet.Servlet;
@@ -46,6 +47,7 @@ import org.osgi.service.http.whiteboard.propertytypes.HttpWhiteboardServletPatte
 @HttpWhiteboardServletPattern(CreateAPITokenPageServlet.SERVLET_PATH + "/*")
 public class CreateAPITokenPageServlet extends AbstractAuthPageServlet {
 
+    @Serial
     private static final long serialVersionUID = 5340598701104679843L;
     public static final String SERVLET_PATH = "/createApiToken";
 

bundles/org.openhab.core.io.monitor/src/test/java/org/openhab/core/io/monitor/internal/metrics/ThingStateMetricTest.java

@@ -69,7 +69,7 @@ public class ThingStateMetricTest {
 
         List<Meter> meters = meterRegistry.getMeters();
         assertEquals(1, meters.size());
-        assertEquals(strThingUid, meters.get(0).getId().getTag("thing"));
+        assertEquals(strThingUid, meters.getFirst().getId().getTag("thing"));
 
         // Still only one meter registered after receiving an event
         ThingStatusInfo thingStatusInfo = new ThingStatusInfo(ThingStatus.ONLINE, ThingStatusDetail.NONE, null);
@@ -77,7 +77,7 @@ public class ThingStateMetricTest {
 
         meters = meterRegistry.getMeters();
         assertEquals(1, meters.size());
-        assertEquals(strThingUid, meters.get(0).getId().getTag("thing"));
+        assertEquals(strThingUid, meters.getFirst().getId().getTag("thing"));
 
         // Now another one is added
         thingStateMetric.receive(ThingEventFactory.createStatusInfoEvent(thingUid2, thingStatusInfo));

bundles/org.openhab.core.io.net/src/main/java/org/openhab/core/io/net/http/HttpClientInitializationException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.net.http;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -23,6 +25,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class HttpClientInitializationException extends RuntimeException {
 
+    @Serial
     private static final long serialVersionUID = -3187938868560212413L;
 
     public HttpClientInitializationException(String message, @Nullable Throwable cause) {

bundles/org.openhab.core.io.rest.auth/src/main/java/org/openhab/core/io/rest/auth/internal/JwtHelper.java

@@ -17,7 +17,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
-import java.nio.file.Paths;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
@@ -84,7 +84,7 @@ public class JwtHelper {
     }
 
     private RsaJsonWebKey loadOrGenerateKey() throws JoseException, IOException {
-        try (final BufferedReader reader = Files.newBufferedReader(Paths.get(KEY_FILE_PATH))) {
+        try (final BufferedReader reader = Files.newBufferedReader(Path.of(KEY_FILE_PATH))) {
             return (RsaJsonWebKey) JsonWebKey.Factory.newJwk(reader.readLine());
         } catch (IOException | JoseException e) {
             RsaJsonWebKey key = generateNewKey();

bundles/org.openhab.core.io.rest.auth/src/main/java/org/openhab/core/io/rest/auth/internal/TokenEndpointException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.rest.auth.internal;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.auth.AuthenticationException;
 
@@ -26,6 +28,7 @@ import org.openhab.core.auth.AuthenticationException;
  */
 @NonNullByDefault
 public class TokenEndpointException extends AuthenticationException {
+    @Serial
     private static final long serialVersionUID = 610324537843397832L;
 
     /**

bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/link/ItemChannelLinkResource.java

@@ -179,7 +179,7 @@ public class ItemChannelLinkResource implements RESTResource {
                 .toList();
 
         if (!links.isEmpty()) {
-            return JSONResponse.createResponse(Status.OK, links.get(0), null);
+            return JSONResponse.createResponse(Status.OK, links.getFirst(), null);
         }
         return JSONResponse.createErrorResponse(Status.NOT_FOUND,
                 "No link found for item '" + itemName + "' + and channelUID '" + channelUid + "'");

bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/service/ConfigurableServiceResource.java

@@ -174,7 +174,7 @@ public class ConfigurableServiceResource implements RESTResource {
                 + "=*))";
         List<ConfigurableServiceDTO> services = getServicesByFilter(filter, locale);
         if (services.size() == 1) {
-            return services.get(0);
+            return services.getFirst();
         }
         return null;
     }
@@ -391,9 +391,9 @@ public class ConfigurableServiceResource implements RESTResource {
             case 0:
                 return "";
             case 1:
-                return pids.get(0);
+                return pids.getFirst();
             default: // multiple entries
-                final String first = pids.get(0);
+                final String first = pids.getFirst();
                 boolean differences = false;
                 for (int i = 1; i < pids.size(); ++i) {
                     if (!first.equals(pids.get(i))) {

bundles/org.openhab.core.io.rest.core/src/test/java/org/openhab/core/io/rest/core/config/EnrichedConfigDescriptionDTOMapperTest.java

@@ -49,7 +49,7 @@ public class EnrichedConfigDescriptionDTOMapperTest {
         ConfigDescriptionDTO cddto = EnrichedConfigDescriptionDTOMapper.map(configDescription);
         assertThat(cddto.parameters, hasSize(1));
 
-        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.get(0);
+        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.getFirst();
         assertThat(cdpdto, instanceOf(EnrichedConfigDescriptionParameterDTO.class));
         assertThat(cdpdto.defaultValue, is(nullValue()));
         EnrichedConfigDescriptionParameterDTO ecdpdto = (EnrichedConfigDescriptionParameterDTO) cdpdto;
@@ -66,7 +66,7 @@ public class EnrichedConfigDescriptionDTOMapperTest {
         ConfigDescriptionDTO cddto = EnrichedConfigDescriptionDTOMapper.map(configDescription);
         assertThat(cddto.parameters, hasSize(1));
 
-        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.get(0);
+        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.getFirst();
         assertThat(cdpdto, instanceOf(EnrichedConfigDescriptionParameterDTO.class));
         assertThat(cdpdto.defaultValue, is(CONFIG_PARAMETER_DEFAULT_VALUE));
         EnrichedConfigDescriptionParameterDTO ecdpdto = (EnrichedConfigDescriptionParameterDTO) cdpdto;
@@ -84,7 +84,7 @@ public class EnrichedConfigDescriptionDTOMapperTest {
         ConfigDescriptionDTO cddto = EnrichedConfigDescriptionDTOMapper.map(configDescription);
         assertThat(cddto.parameters, hasSize(1));
 
-        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.get(0);
+        ConfigDescriptionParameterDTO cdpdto = cddto.parameters.getFirst();
         assertThat(cdpdto, instanceOf(EnrichedConfigDescriptionParameterDTO.class));
         assertThat(cdpdto.defaultValue, is(CONFIG_PARAMETER_DEFAULT_VALUE));
         EnrichedConfigDescriptionParameterDTO ecdpdto = (EnrichedConfigDescriptionParameterDTO) cdpdto;

bundles/org.openhab.core.io.rest.core/src/test/java/org/openhab/core/io/rest/core/internal/persistence/PersistenceResourceTest.java

@@ -127,7 +127,7 @@ public class PersistenceResourceTest {
 
         // since we added binary state type elements, all except the first have to be repeated but with the timestamp of
         // the following item
-        HistoryDataBean item0 = dto.data.get(0);
+        HistoryDataBean item0 = dto.data.getFirst();
         HistoryDataBean item1 = dto.data.get(1);
 
         assertEquals(item0.state, item1.state);

bundles/org.openhab.core.io.rest.core/src/test/java/org/openhab/core/io/rest/core/thing/EnrichedThingDTOMapperTest.java

@@ -94,9 +94,9 @@ public class EnrichedThingDTOMapperTest {
 
     private void assertChannels(EnrichedThingDTO enrichedThingDTO) {
         assertThat(enrichedThingDTO.channels, hasSize(2));
-        assertThat(enrichedThingDTO.channels.get(0), is(instanceOf(EnrichedChannelDTO.class)));
+        assertThat(enrichedThingDTO.channels.getFirst(), is(instanceOf(EnrichedChannelDTO.class)));
 
-        EnrichedChannelDTO channel1 = enrichedThingDTO.channels.get(0);
+        EnrichedChannelDTO channel1 = enrichedThingDTO.channels.getFirst();
         assertThat(channel1.linkedItems, hasSize(2));
     }
 

bundles/org.openhab.core.io.rest.sitemap/src/main/java/org/openhab/core/io/rest/sitemap/SitemapSubscriptionService.java

@@ -299,9 +299,9 @@ public class SitemapSubscriptionService implements ModelRepositoryChangeListener
                 // subscribing to whole sitemap --> get items for all subpages as well
                 LinkedList<Widget> childrenQueue = new LinkedList<>(widgets);
                 while (!childrenQueue.isEmpty()) {
-                    Widget child = childrenQueue.remove(0);
+                    Widget child = childrenQueue.removeFirst();
-                    if (child instanceof LinkableWidget) {
+                    if (child instanceof LinkableWidget widget) {
-                        List<Widget> subWidgets = itemUIRegistry.getChildren((LinkableWidget) child);
+                        List<Widget> subWidgets = itemUIRegistry.getChildren(widget);
                         widgets.addAll(subWidgets);
                         childrenQueue.addAll(subWidgets);
                     }

bundles/org.openhab.core.io.rest.sitemap/src/test/java/org/openhab/core/io/rest/sitemap/internal/SitemapResourceTest.java

@@ -358,18 +358,18 @@ public class SitemapResourceTest extends JavaTest {
         assertThat(pageDTO.widgets, notNullValue());
         assertThat((Collection<?>) pageDTO.widgets, hasSize(3));
 
-        assertThat(pageDTO.widgets.get(0).widgetId, is(WIDGET1_ID));
+        assertThat(pageDTO.widgets.getFirst().widgetId, is(WIDGET1_ID));
-        assertThat(pageDTO.widgets.get(0).label, is(WIDGET1_LABEL));
+        assertThat(pageDTO.widgets.getFirst().label, is(WIDGET1_LABEL));
-        assertThat(pageDTO.widgets.get(0).labelSource, is("SITEMAP_WIDGET"));
+        assertThat(pageDTO.widgets.getFirst().labelSource, is("SITEMAP_WIDGET"));
-        assertThat(pageDTO.widgets.get(0).labelcolor, is("GREEN"));
+        assertThat(pageDTO.widgets.getFirst().labelcolor, is("GREEN"));
-        assertThat(pageDTO.widgets.get(0).valuecolor, is("BLUE"));
+        assertThat(pageDTO.widgets.getFirst().valuecolor, is("BLUE"));
-        assertThat(pageDTO.widgets.get(0).iconcolor, is("ORANGE"));
+        assertThat(pageDTO.widgets.getFirst().iconcolor, is("ORANGE"));
-        assertThat(pageDTO.widgets.get(0).icon, is(WIDGET1_ICON));
+        assertThat(pageDTO.widgets.getFirst().icon, is(WIDGET1_ICON));
-        assertThat(pageDTO.widgets.get(0).staticIcon, is(true));
+        assertThat(pageDTO.widgets.getFirst().staticIcon, is(true));
-        assertThat(pageDTO.widgets.get(0).state, nullValue());
+        assertThat(pageDTO.widgets.getFirst().state, nullValue());
-        assertThat(pageDTO.widgets.get(0).item, notNullValue());
+        assertThat(pageDTO.widgets.getFirst().item, notNullValue());
-        assertThat(pageDTO.widgets.get(0).item.name, is(ITEM_NAME));
+        assertThat(pageDTO.widgets.getFirst().item.name, is(ITEM_NAME));
-        assertThat(pageDTO.widgets.get(0).item.state, is("50"));
+        assertThat(pageDTO.widgets.getFirst().item.state, is("50"));
 
         assertThat(pageDTO.widgets.get(1).widgetId, is(WIDGET2_ID));
         assertThat(pageDTO.widgets.get(1).label, is(ITEM_LABEL));
@@ -399,7 +399,7 @@ public class SitemapResourceTest extends JavaTest {
 
     private void configureItemUIRegistryWithSubpages(State state1, State state2, State state3)
             throws ItemNotFoundException {
-        Group group1 = (Group) widgets.get(0);
+        Group group1 = (Group) widgets.getFirst();
         Group group2 = (Group) widgets.get(4);
 
         when(itemUIRegistryMock.getChildren(defaultSitemapMock)).thenReturn(new BasicEList<>(List.of(group1, group2)));
@@ -441,7 +441,7 @@ public class SitemapResourceTest extends JavaTest {
 
     private void configureWidgetStatesPage1(State state1, State state2) {
         EList<Widget> mainpageWidgets = new BasicEList<>(widgets.subList(1, 4));
-        Widget w1 = mainpageWidgets.get(0);
+        Widget w1 = mainpageWidgets.getFirst();
         configureItemUIRegistryForWidget(w1, WIDGET1_ID, WIDGET1_ICON, WIDGET1_LABEL, WidgetLabelSource.SITEMAP_WIDGET,
                 true, "GREEN", "BLUE", "ORANGE", state1);
 

bundles/org.openhab.core.io.rest.sse/src/test/java/org/openhab/core/io/rest/sse/internal/util/SseUtilTest.java

@@ -62,9 +62,9 @@ public class SseUtilTest {
         List<String> regexes = SseUtil
                 .convertToRegex("openhab/*/test/test/test/test,    openhab/test/*/test/test/test, openhab/*,qivicon/*");
 
-        assertThat("openhab/test/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/test/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/asdf/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.get(0)), is(false));
+        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.getFirst()), is(false));
 
         assertThat("openhab/test/test/test/test/test".matches(regexes.get(1)), is(true));
         assertThat("openhab/asdf/test/test/test/test".matches(regexes.get(1)), is(false));
@@ -83,9 +83,9 @@ public class SseUtilTest {
     public void testMoreFilterMatchers() {
         List<String> regexes = SseUtil.convertToRegex(",    *, openhab/items/*/added, openhab/items/*/*");
 
-        assertThat("openhab/test/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/test/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/asdf/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.getFirst()), is(true));
 
         assertThat("openhab/test/test/test/test/test".matches(regexes.get(1)), is(false));
         assertThat("openhab/items/anyitem/added".matches(regexes.get(1)), is(true));
@@ -101,20 +101,20 @@ public class SseUtilTest {
     public void testEvenMoreFilterMatchers() {
         List<String> regexes = SseUtil.convertToRegex("");
 
-        assertThat("openhab/test/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/test/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/test/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/asdf/test/test/test/test".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.get(0)), is(true));
+        assertThat("openhab/asdf/ASDF/test/test/test".matches(regexes.getFirst()), is(true));
 
         regexes = SseUtil.convertToRegex("*/added");
-        assertThat("openhab/items/anyitem/added".matches(regexes.get(0)), is(true));
+        assertThat("openhab/items/anyitem/added".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/items/anyitem/removed".matches(regexes.get(0)), is(false));
+        assertThat("openhab/items/anyitem/removed".matches(regexes.getFirst()), is(false));
 
         regexes = SseUtil.convertToRegex("*added");
-        assertThat("openhab/items/anyitem/added".matches(regexes.get(0)), is(true));
+        assertThat("openhab/items/anyitem/added".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/items/anyitem/removed".matches(regexes.get(0)), is(false));
+        assertThat("openhab/items/anyitem/removed".matches(regexes.getFirst()), is(false));
 
         regexes = SseUtil.convertToRegex("openhab/items/*/state");
-        assertThat("openhab/items/anyitem/state".matches(regexes.get(0)), is(true));
+        assertThat("openhab/items/anyitem/state".matches(regexes.getFirst()), is(true));
-        assertThat("openhab/items/anyitem/statechanged".matches(regexes.get(0)), is(false));
+        assertThat("openhab/items/anyitem/statechanged".matches(regexes.getFirst()), is(false));
     }
 }

bundles/org.openhab.core.io.rest/src/main/java/org/openhab/core/io/rest/LocaleServiceImpl.java

@@ -52,9 +52,9 @@ public class LocaleServiceImpl implements LocaleService {
                 split = acceptLanguageHttpHeader.split("-");
             }
             if (split.length == 2) {
-                locale = new Locale(split[0], split[1]);
+                locale = Locale.of(split[0], split[1]);
             } else {
-                locale = new Locale(split[0]);
+                locale = Locale.of(split[0]);
             }
         }
         return locale;

bundles/org.openhab.core.io.rest/src/main/java/org/openhab/core/io/rest/internal/filter/CorsFilter.java

@@ -157,7 +157,7 @@ public class CorsFilter implements ContainerResponseFilter {
         if (values == null || values.isEmpty()) {
             return null;
         }
-        return values.get(0);
+        return values.getFirst();
     }
 
     /**

bundles/org.openhab.core.io.rest/src/main/java/org/openhab/core/io/rest/internal/filter/ProxyFilter.java

@@ -129,6 +129,6 @@ public class ProxyFilter implements ContainerRequestFilter {
             return null;
         }
 
-        return values.get(0);
+        return values.getFirst();
     }
 }

bundles/org.openhab.core.io.rest/src/test/java/org/openhab/core/io/rest/JSONResponseTest.java

@@ -23,6 +23,7 @@ import java.math.BigDecimal;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
 
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
@@ -139,7 +140,7 @@ public class JSONResponseTest {
         private List<BigDecimal> getRandoms() {
             List<BigDecimal> randoms = new ArrayList<>();
             for (int i = 0; i < 100000; i++) {
-                randoms.add(new BigDecimal(Math.random()));
+                randoms.add(new BigDecimal(ThreadLocalRandom.current().nextDouble()));
             }
 
             return randoms;

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusConnectionException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.core.io.transport.modbus.endpoint.ModbusSlaveEndpoint;
@@ -25,6 +27,7 @@ import org.openhab.core.io.transport.modbus.endpoint.ModbusSlaveEndpoint;
 @NonNullByDefault
 public class ModbusConnectionException extends ModbusTransportException {
 
+    @Serial
     private static final long serialVersionUID = -6171226761518661925L;
     private ModbusSlaveEndpoint endpoint;
 

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusSlaveErrorResponseException.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
@@ -153,6 +154,7 @@ public abstract class ModbusSlaveErrorResponseException extends ModbusTransportE
     public static final int GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = KnownExceptionCode.GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND
             .getExceptionCode();
 
+    @Serial
     private static final long serialVersionUID = -1435199498550990487L;
 
     /**

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusSlaveIOException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -23,5 +25,6 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class ModbusSlaveIOException extends ModbusTransportException {
 
+    @Serial
     private static final long serialVersionUID = -8568199166837844463L;
 }

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusTransportException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -23,5 +25,6 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class ModbusTransportException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 1684767401685843339L;
 }

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusUnexpectedResponseFunctionCodeException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class ModbusUnexpectedResponseFunctionCodeException extends ModbusTransportException {
 
+    @Serial
     private static final long serialVersionUID = 1109165449703638949L;
     private int requestFunctionCode;
     private int responseFunctionCode;

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusUnexpectedResponseSizeException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class ModbusUnexpectedResponseSizeException extends ModbusTransportException {
 
+    @Serial
     private static final long serialVersionUID = 2460907938819984483L;
     private int requestSize;
     private int responseSize;

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/exception/ModbusUnexpectedTransactionIdException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.modbus.exception;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class ModbusUnexpectedTransactionIdException extends ModbusTransportException {
 
+    @Serial
     private static final long serialVersionUID = -2453232634024813933L;
     private int requestId;
     private int responseId;

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/internal/ModbusSlaveErrorResponseExceptionImpl.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.io.transport.modbus.internal;
 
+import java.io.Serial;
 import java.util.Optional;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -30,6 +31,7 @@ import net.wimpi.modbus.ModbusSlaveException;
 @NonNullByDefault
 public class ModbusSlaveErrorResponseExceptionImpl extends ModbusSlaveErrorResponseException {
 
+    @Serial
     private static final long serialVersionUID = 6334580162425192133L;
     private int rawCode;
     private Optional<KnownExceptionCode> exceptionCode;

bundles/org.openhab.core.io.transport.modbus/src/main/java/org/openhab/core/io/transport/modbus/internal/ModbusSlaveIOExceptionImpl.java

@@ -13,6 +13,7 @@
 package org.openhab.core.io.transport.modbus.internal;
 
 import java.io.IOException;
+import java.io.Serial;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -29,6 +30,7 @@ import net.wimpi.modbus.ModbusIOException;
 @NonNullByDefault
 public class ModbusSlaveIOExceptionImpl extends ModbusSlaveIOException {
 
+    @Serial
     private static final long serialVersionUID = -8910463902857643468L;
     private Exception error;
 

bundles/org.openhab.core.io.transport.modbus/src/test/java/org/openhab/core/io/transport/modbus/test/SmokeTest.java

@@ -440,7 +440,7 @@ public class SmokeTest extends IntegrationTestSupport {
                 assertThat(response.getFunctionCode(), is(equalTo(15)));
 
                 assertThat(modbustRequestCaptor.getAllReturnValues().size(), is(equalTo(1)));
-                ModbusRequest request = modbustRequestCaptor.getAllReturnValues().get(0);
+                ModbusRequest request = modbustRequestCaptor.getAllReturnValues().getFirst();
                 assertThat(request.getFunctionCode(), is(equalTo(15)));
                 assertThat(((WriteMultipleCoilsRequest) request).getReference(), is(equalTo(3)));
                 assertThat(((WriteMultipleCoilsRequest) request).getBitCount(), is(equalTo(bits.size())));
@@ -481,7 +481,7 @@ public class SmokeTest extends IntegrationTestSupport {
             assertInstanceOf(ModbusSlaveErrorResponseException.class, lastError.get(), lastError.toString());
 
             assertThat(modbustRequestCaptor.getAllReturnValues().size(), is(equalTo(1)));
-            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().get(0);
+            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().getFirst();
             assertThat(request.getFunctionCode(), is(equalTo(15)));
             assertThat(((WriteMultipleCoilsRequest) request).getReference(), is(equalTo(3)));
             assertThat(((WriteMultipleCoilsRequest) request).getBitCount(), is(equalTo(bits.size())));
@@ -520,7 +520,7 @@ public class SmokeTest extends IntegrationTestSupport {
             assertThat(response.getFunctionCode(), is(equalTo(5)));
 
             assertThat(modbustRequestCaptor.getAllReturnValues().size(), is(equalTo(1)));
-            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().get(0);
+            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().getFirst();
             assertThat(request.getFunctionCode(), is(equalTo(5)));
             assertThat(((WriteCoilRequest) request).getReference(), is(equalTo(3)));
             assertThat(((WriteCoilRequest) request).getCoil(), is(equalTo(true)));
@@ -558,7 +558,7 @@ public class SmokeTest extends IntegrationTestSupport {
             assertInstanceOf(ModbusSlaveErrorResponseException.class, lastError.get(), lastError.toString());
 
             assertThat(modbustRequestCaptor.getAllReturnValues().size(), is(equalTo(1)));
-            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().get(0);
+            ModbusRequest request = modbustRequestCaptor.getAllReturnValues().getFirst();
             assertThat(request.getFunctionCode(), is(equalTo(5)));
             assertThat(((WriteCoilRequest) request).getReference(), is(equalTo(300)));
             assertThat(((WriteCoilRequest) request).getCoil(), is(equalTo(true)));

bundles/org.openhab.core.io.transport.mqtt/src/main/java/org/openhab/core/io/transport/mqtt/MqttException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.mqtt;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -23,6 +25,7 @@ import org.eclipse.jdt.annotation.Nullable;
  */
 @NonNullByDefault
 public class MqttException extends Exception {
+    @Serial
     private static final long serialVersionUID = 301L;
     private Throwable cause;
 

bundles/org.openhab.core.io.transport.serial/src/main/java/org/openhab/core/io/transport/serial/PortInUseException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.serial;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -22,6 +24,7 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class PortInUseException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = -2709480420743139383L;
 
     public PortInUseException(String message, Exception cause) {

bundles/org.openhab.core.io.transport.serial/src/main/java/org/openhab/core/io/transport/serial/UnsupportedCommOperationException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.transport.serial;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -22,6 +24,7 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
 @NonNullByDefault
 public class UnsupportedCommOperationException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     public UnsupportedCommOperationException() {

bundles/org.openhab.core.io.websocket/src/main/java/org/openhab/core/io/websocket/CommonWebSocketServlet.java

@@ -13,6 +13,7 @@
 package org.openhab.core.io.websocket;
 
 import java.io.IOException;
+import java.io.Serial;
 import java.util.Base64;
 import java.util.HashMap;
 import java.util.Map;
@@ -65,6 +66,7 @@ import org.slf4j.LoggerFactory;
 @HttpWhiteboardServletPattern(CommonWebSocketServlet.SERVLET_PATH + "/*")
 @Component(immediate = true, service = { Servlet.class })
 public class CommonWebSocketServlet extends WebSocketServlet {
+    @Serial
     private static final long serialVersionUID = 1L;
 
     public static final String SEC_WEBSOCKET_PROTOCOL_HEADER = "Sec-WebSocket-Protocol";

bundles/org.openhab.core.io.websocket/src/main/java/org/openhab/core/io/websocket/event/EventProcessingException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.io.websocket.event;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -21,6 +23,7 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
  */
 @NonNullByDefault
 public class EventProcessingException extends Exception {
+    @Serial
     private static final long serialVersionUID = 1L;
 
     public EventProcessingException(String message) {

bundles/org.openhab.core.karaf/src/main/java/org/openhab/core/karaf/internal/FeatureInstaller.java

@@ -18,7 +18,6 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -283,7 +282,7 @@ public class FeatureInstaller implements ConfigurationListener {
     }
 
     private void setOnlineRepoUrl() {
-        Path versionFilePath = Paths.get(OpenHAB.getUserDataFolder(), "etc", "version.properties");
+        Path versionFilePath = Path.of(OpenHAB.getUserDataFolder(), "etc", "version.properties");
         try (BufferedReader reader = Files.newBufferedReader(versionFilePath)) {
             Properties prop = new Properties();
             prop.load(reader);

bundles/org.openhab.core.model.core/src/main/java/org/openhab/core/model/core/internal/ModelRepositoryImpl.java

@@ -81,7 +81,7 @@ public class ModelRepositoryImpl implements ModelRepository {
             Resource resource = getResource(name);
             if (resource != null) {
                 if (!resource.getContents().isEmpty()) {
-                    return resource.getContents().get(0);
+                    return resource.getContents().getFirst();
                 } else {
                     logger.warn("Configuration model '{}' is either empty or cannot be parsed correctly!", name);
                     resourceSet.getResources().remove(resource);
@@ -274,7 +274,7 @@ public class ModelRepositoryImpl implements ModelRepository {
                 // Check for validation errors, but log them only
                 try {
                     final org.eclipse.emf.common.util.Diagnostic diagnostic = safeEmf
-                            .call(() -> Diagnostician.INSTANCE.validate(resource.getContents().get(0)));
+                            .call(() -> Diagnostician.INSTANCE.validate(resource.getContents().getFirst()));
                     for (org.eclipse.emf.common.util.Diagnostic d : diagnostic.getChildren()) {
                         warnings.add(d.getMessage());
                     }

bundles/org.openhab.core.model.core/src/test/java/org/openhab/core/model/core/internal/folder/FolderObserverTest.java

@@ -29,7 +29,6 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
 import java.util.Comparator;
 import java.util.Dictionary;
@@ -253,7 +252,7 @@ public class FolderObserverTest extends JavaTest {
         configProps.put(subdir, "");
         folderObserver.activate(contextMock);
 
-        File file = new File(WATCHED_DIRECTORY, Paths.get(subdir, "MockFileInNoExtSubDir.txt").toString());
+        File file = new File(WATCHED_DIRECTORY, Path.of(subdir, "MockFileInNoExtSubDir.txt").toString());
         Files.writeString(file.toPath(), INITIAL_FILE_CONTENT, StandardCharsets.UTF_8, StandardOpenOption.CREATE);
         waitForAssert(() -> assertThat(file.exists(), is(true)));
 

bundles/org.openhab.core.model.item/src/org/openhab/core/model/item/BindingConfigParseException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.model.item;
 
+import java.io.Serial;
+
 /**
  * This exception is used by {@link BindingConfigReader} instances if parsing configurations fails
  *
@@ -19,6 +21,7 @@ package org.openhab.core.model.item;
  */
 public class BindingConfigParseException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = 1434607160082879845L;
 
     public BindingConfigParseException(String msg) {

bundles/org.openhab.core.model.item/src/org/openhab/core/model/item/internal/GenericItemProvider.java

@@ -354,7 +354,7 @@ public class GenericItemProvider extends AbstractProvider<Item>
                 // Single valued lists get unwrapped to just their one value for
                 // backwards compatibility
                 if (value instanceof List listValue && listValue.size() == 1) {
-                    value = listValue.get(0);
+                    value = listValue.getFirst();
                 }
                 configuration.put(p.getKey(), value);
             });

bundles/org.openhab.core.model.lsp/src/main/java/org/openhab/core/model/lsp/internal/MappingUriExtensions.java

@@ -16,7 +16,6 @@ import java.io.File;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -50,7 +49,7 @@ public class MappingUriExtensions extends UriExtensions {
     }
 
     protected String calcServerLocation(String configFolder) {
-        Path configPath = Paths.get(configFolder);
+        Path configPath = Path.of(configFolder);
         Path absoluteConfigPath = configPath.toAbsolutePath();
         java.net.URI configPathURI = absoluteConfigPath.toUri();
         return removeTrailingSlash(configPathURI.toString());
@@ -184,6 +183,6 @@ public class MappingUriExtensions extends UriExtensions {
         // output new: file:///d/
 
         // We use this method now to keep the old behavior.
-        return Paths.get(uri).toUri().toString();
+        return Path.of(uri).toUri().toString();
     }
 }

bundles/org.openhab.core.model.rule/src/org/openhab/core/model/rule/scoping/RulesClassCache.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.model.rule.scoping;
 
+import java.io.Serial;
 import java.util.HashMap;
 
 import org.eclipse.xtext.common.types.access.impl.Primitives;
@@ -36,6 +37,7 @@ import org.slf4j.LoggerFactory;
 @Component
 public class RulesClassCache extends HashMap<String, Class<?>> {
 
+    @Serial
     private static final long serialVersionUID = 1L;
 
     private static RulesClassCache instance;

bundles/org.openhab.core.model.script.runtime/src/org/openhab/core/model/script/runtime/internal/engine/ScriptEngineImpl.java

@@ -16,6 +16,7 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ThreadLocalRandom;
 
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.URI;
@@ -143,9 +144,9 @@ public class ScriptEngineImpl implements ScriptEngine, ModelParser {
 
         EList<EObject> contents = resource.getContents();
         if (!contents.isEmpty()) {
-            Iterable<Issue> validationErrors = getValidationErrors(contents.get(0));
+            Iterable<Issue> validationErrors = getValidationErrors(contents.getFirst());
             if (!validationErrors.iterator().hasNext()) {
-                return (XExpression) contents.get(0);
+                return (XExpression) contents.getFirst();
             } else {
                 deleteResource(resource);
                 throw new ScriptParsingException("Failed to parse expression (due to managed ValidationError/s)",
@@ -162,7 +163,8 @@ public class ScriptEngineImpl implements ScriptEngine, ModelParser {
         final int MAX_TRIES = 1000;
         for (int i = 0; i < MAX_TRIES; i++) {
             // NOTE: The "filename extension" (".script") must match the file.extensions in the *.mwe2
-            URI syntheticUri = URI.createURI(name + Math.random() + "." + Script.SCRIPT_FILEEXT);
+            URI syntheticUri = URI
+                    .createURI(name + ThreadLocalRandom.current().nextDouble() + "." + Script.SCRIPT_FILEEXT);
             if (resourceSet.getResource(syntheticUri, false) == null) {
                 return syntheticUri;
             }

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/actions/TransformationException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.model.script.actions;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -24,6 +26,7 @@ import org.eclipse.jdt.annotation.Nullable;
 @NonNullByDefault
 public class TransformationException extends Exception {
 
+    @Serial
     private static final long serialVersionUID = -1L;
 
     public TransformationException(@Nullable String message) {

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/actions/Voice.java

@@ -325,9 +325,9 @@ public class Voice {
             String[] split = locale.split("-");
             Locale loc;
             if (split.length == 2) {
-                loc = new Locale(split[0], split[1]);
+                loc = Locale.of(split[0], split[1]);
             } else {
-                loc = new Locale(split[0]);
+                loc = Locale.of(split[0]);
             }
             dialogContextBuilder.withLocale(loc);
         }
@@ -453,9 +453,9 @@ public class Voice {
                 Locale loc;
                 String[] split = locale.split("-");
                 if (split.length == 2) {
-                    loc = new Locale(split[0], split[1]);
+                    loc = Locale.of(split[0], split[1]);
                 } else {
-                    loc = new Locale(split[0]);
+                    loc = Locale.of(split[0]);
                 }
                 dialogContextBuilder.withLocale(loc);
             }

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/engine/ScriptException.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.model.script.engine;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
@@ -22,6 +23,7 @@ import java.util.List;
  * @author Kai Kreuzer - Initial contribution
  */
 public abstract class ScriptException extends Exception {
+    @Serial
     private static final long serialVersionUID = -4155948282895039148L;
 
     private String scriptText;

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/engine/ScriptExecutionException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.model.script.engine;
 
+import java.io.Serial;
+
 /**
  * Exception that is thrown on errors during script execution.
  *
@@ -19,6 +21,7 @@ package org.openhab.core.model.script.engine;
  */
 public class ScriptExecutionException extends ScriptException {
 
+    @Serial
     private static final long serialVersionUID = 149490362444673405L;
 
     public ScriptExecutionException(final String message, final int line, final int column, final int length) {

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/engine/ScriptParsingException.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.model.script.engine;
 
+import java.io.Serial;
 import java.util.List;
 
 import org.eclipse.emf.ecore.resource.Resource.Diagnostic;
@@ -26,6 +27,7 @@ import org.eclipse.xtext.validation.Issue;
  */
 public class ScriptParsingException extends ScriptException {
 
+    @Serial
     private static final long serialVersionUID = -3784970293118871807L;
 
     public ScriptParsingException(String message, String scriptAsString) {

bundles/org.openhab.core.model.thing/src/org/openhab/core/model/thing/serializer/ThingSyntacticSequencerExtension.java

@@ -30,8 +30,8 @@ public class ThingSyntacticSequencerExtension extends ThingSyntacticSequencer {
     @Override
     protected void emit_ModelThing_ThingKeyword_0_q(EObject semanticObject, ISynNavigable transition,
             List<INode> nodes) {
-        ILeafNode node = nodes != null && nodes.size() == 1 && nodes.get(0) instanceof ILeafNode
+        ILeafNode node = nodes != null && nodes.size() == 1 && nodes.getFirst() instanceof ILeafNode
-                ? (ILeafNode) nodes.get(0)
+                ? (ILeafNode) nodes.getFirst()
                 : null;
         Keyword keyword = grammarAccess.getModelThingAccess().getThingKeyword_0();
         acceptUnassignedKeyword(keyword, keyword.getValue(), node);

bundles/org.openhab.core.model.yaml/src/test/java/org/openhab/core/model/yaml/internal/YamlModelRepositoryImplTest.java

@@ -157,7 +157,7 @@ public class YamlModelRepositoryImplTest {
         assertThat(arguments, hasSize(4));
 
         // added originally
-        assertThat(arguments.get(0), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
+        assertThat(arguments.getFirst(), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
                 new FirstTypeDTO("Second", "Second original"), new FirstTypeDTO("Third", "Third original")));
         // added by update
         assertThat(arguments.get(1), contains(new FirstTypeDTO("Fourth", "Fourth original")));
@@ -185,10 +185,10 @@ public class YamlModelRepositoryImplTest {
         assertThat(arguments, hasSize(2));
 
         // all are added
-        assertThat(arguments.get(0), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
+        assertThat(arguments.getFirst(), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
                 new FirstTypeDTO("Second", "Second original"), new FirstTypeDTO("Third", "Third original")));
         // all are removed
-        assertThat(arguments.get(0), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
+        assertThat(arguments.getFirst(), containsInAnyOrder(new FirstTypeDTO("First", "First original"),
                 new FirstTypeDTO("Second", "Second original"), new FirstTypeDTO("Third", "Third original")));
     }
 

bundles/org.openhab.core.persistence/src/main/java/org/openhab/core/persistence/extensions/PersistenceExtensions.java

@@ -2681,20 +2681,19 @@ public class PersistenceExtensions {
         }
 
         // add HistoricItem at begin
-        if (betweenItemsList.isEmpty() || !betweenItemsList.get(0).getTimestamp().equals(begin)) {
+        if (betweenItemsList.isEmpty() || !betweenItemsList.getFirst().getTimestamp().equals(begin)) {
             HistoricItem first = beginTime.equals(now) ? historicItemOrCurrentState(item, null)
                     : internalPersistedState(item, beginTime, serviceId);
             if (first != null) {
                 first = new RetimedHistoricItem(first, beginTime);
             }
             if (first != null) {
-                betweenItemsList.add(0, first);
+                betweenItemsList.addFirst(first);
             }
         }
 
         // add HistoricItem at end
-        if (betweenItemsList.isEmpty()
+        if (betweenItemsList.isEmpty() || !betweenItemsList.getLast().getTimestamp().equals(end)) {
-                || !betweenItemsList.get(betweenItemsList.size() - 1).getTimestamp().equals(end)) {
             HistoricItem last = endTime.equals(now) ? historicItemOrCurrentState(item, null)
                     : internalPersistedState(item, endTime, serviceId);
             if (last != null) {

bundles/org.openhab.core.persistence/src/test/java/org/openhab/core/persistence/internal/PersistenceManagerTest.java

@@ -415,7 +415,7 @@ public class PersistenceManagerTest {
         assertThat(filterCriteria.getEndDate(), is(time4.atZone(ZoneId.systemDefault())));
 
         // verify restore future is not cancelled
-        verify(futures.get(0), never()).cancel(anyBoolean());
+        verify(futures.getFirst(), never()).cancel(anyBoolean());
 
         // verify new values are stored
         inOrder.verify(service, times(2)).store(any(Item.class), any(ZonedDateTime.class), any(State.class));
@@ -430,7 +430,7 @@ public class PersistenceManagerTest {
         manager.timeSeriesUpdated(TEST_ITEM, timeSeries3);
         // verify old restore future is cancelled
         inOrder.verify(service, times(1)).store(any(Item.class), any(ZonedDateTime.class), any(State.class));
-        verify(futures.get(0)).cancel(true);
+        verify(futures.getFirst()).cancel(true);
 
         // verify new restore future is properly created
         inOrder.verify(schedulerMock).at(any(SchedulerRunnable.class), eq(time5));
@@ -452,8 +452,8 @@ public class PersistenceManagerTest {
         verify(readyServiceMock, timeout(1000)).markReady(any());
         List<SchedulerRunnable> runnables = runnableCaptor.getAllValues();
         assertThat(runnables.size(), is(2));
-        runnables.get(0).run();
+        runnables.getFirst().run();
-        runnables.get(0).run();
+        runnables.getFirst().run();
         runnables.get(1).run();
         runnables.get(1).run();
 

bundles/org.openhab.core.semantics/src/main/java/org/openhab/core/semantics/internal/SemanticsMetadataProvider.java

@@ -164,7 +164,7 @@ public class SemanticsMetadataProvider extends AbstractProvider<Metadata>
             return;
         }
         for (Entry<List<Class<? extends Tag>>, String> relation : propertyRelations.entrySet()) {
-            Class<? extends Tag> entityClass = relation.getKey().get(0);
+            Class<? extends Tag> entityClass = relation.getKey().getFirst();
             if (entityClass.isAssignableFrom(type)) {
                 Class<? extends Property> p = SemanticTags.getProperty(item);
                 if (p != null) {
@@ -211,7 +211,7 @@ public class SemanticsMetadataProvider extends AbstractProvider<Metadata>
         }
         for (Entry<List<Class<? extends Tag>>, String> relation : parentRelations.entrySet()) {
             List<Class<? extends Tag>> relClasses = relation.getKey();
-            Class<? extends Tag> entityClass = relClasses.get(0);
+            Class<? extends Tag> entityClass = relClasses.getFirst();
             Class<? extends Tag> parentClass = relClasses.get(1);
             // process relations of locations
             if (entityClass.isAssignableFrom(type)) {
@@ -236,7 +236,7 @@ public class SemanticsMetadataProvider extends AbstractProvider<Metadata>
         }
         for (Entry<List<Class<? extends Tag>>, String> relation : memberRelations.entrySet()) {
             List<Class<? extends Tag>> relClasses = relation.getKey();
-            Class<? extends Tag> entityClass = relClasses.get(0);
+            Class<? extends Tag> entityClass = relClasses.getFirst();
             Class<? extends Tag> parentClass = relClasses.get(1);
             // process relations of locations
             if (entityClass.isAssignableFrom(type)) {

bundles/org.openhab.core.semantics/src/test/java/org/openhab/core/semantics/internal/SemanticsServiceImplTest.java

@@ -160,7 +160,7 @@ public class SemanticsServiceImplTest {
     public void testGetLabelAndSynonyms() {
         List<String> result = service.getLabelAndSynonyms(bathroomTagClass, Locale.ENGLISH);
         assertEquals(6, result.size());
-        assertEquals("bathroom", result.get(0));
+        assertEquals("bathroom", result.getFirst());
         assertEquals("bathrooms", result.get(1));
         assertEquals("bath", result.get(2));
         assertEquals("baths", result.get(3));
@@ -169,14 +169,14 @@ public class SemanticsServiceImplTest {
 
         result = service.getLabelAndSynonyms(cleaningRobotTagClass, Locale.FRENCH);
         assertEquals(4, result.size());
-        assertEquals("robot de nettoyage", result.get(0));
+        assertEquals("robot de nettoyage", result.getFirst());
         assertEquals("robos de nettoyage", result.get(1));
         assertEquals("robot aspirateur", result.get(2));
         assertEquals("robots aspirateur", result.get(3));
 
         result = service.getLabelAndSynonyms(userLocationTagClass, Locale.ENGLISH);
         assertEquals(4, result.size());
-        assertEquals("custom label", result.get(0));
+        assertEquals("custom label", result.getFirst());
         assertEquals("synonym1", result.get(1));
         assertEquals("synonym2", result.get(2));
         assertEquals("synonym with space", result.get(3));
@@ -204,28 +204,28 @@ public class SemanticsServiceImplTest {
     public void testGetByLabelOrSynonym() {
         List<Class<? extends Tag>> tags = service.getByLabelOrSynonym("BATHROOM", Locale.ENGLISH);
         assertEquals(1, tags.size());
-        assertEquals(bathroomTagClass, tags.get(0));
+        assertEquals(bathroomTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("POWDER Rooms", Locale.ENGLISH);
         assertEquals(1, tags.size());
-        assertEquals(bathroomTagClass, tags.get(0));
+        assertEquals(bathroomTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("other bath", Locale.ENGLISH);
         assertTrue(tags.isEmpty());
 
         tags = service.getByLabelOrSynonym("ROBOT de nettoyage", Locale.FRENCH);
         assertEquals(1, tags.size());
-        assertEquals(cleaningRobotTagClass, tags.get(0));
+        assertEquals(cleaningRobotTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("ROBOTS aspirateur", Locale.FRENCH);
         assertEquals(1, tags.size());
-        assertEquals(cleaningRobotTagClass, tags.get(0));
+        assertEquals(cleaningRobotTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("Robot cuiseur", Locale.FRENCH);
         assertTrue(tags.isEmpty());
 
         tags = service.getByLabelOrSynonym("CUSTOM label", Locale.ENGLISH);
         assertEquals(1, tags.size());
-        assertEquals(userLocationTagClass, tags.get(0));
+        assertEquals(userLocationTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("Synonym with space", Locale.ENGLISH);
         assertEquals(1, tags.size());
-        assertEquals(userLocationTagClass, tags.get(0));
+        assertEquals(userLocationTagClass, tags.getFirst());
         tags = service.getByLabelOrSynonym("wrong label", Locale.ENGLISH);
         assertTrue(tags.isEmpty());
     }

bundles/org.openhab.core.storage.json/src/main/java/org/openhab/core/storage/json/internal/migration/TypeMigrationException.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.core.storage.json.internal.migration;
 
+import java.io.Serial;
+
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
@@ -21,6 +23,7 @@ import org.eclipse.jdt.annotation.NonNullByDefault;
  */
 @NonNullByDefault
 public class TypeMigrationException extends Exception {
+    @Serial
     private static final long serialVersionUID = 1L;
 
     public TypeMigrationException(String message) {

bundles/org.openhab.core.storage.json/src/test/java/org/openhab/core/storage/json/internal/JsonStorageTest.java

@@ -132,10 +132,10 @@ public class JsonStorageTest extends JavaTest {
         assertEquals(0, ((BigDecimal) dummy.configuration.get("testInt")).scale());
         assertEquals(0, ((BigDecimal) dummy.configuration.get("testLong")).scale());
         assertEquals(0, ((BigDecimal) dummy.configuration.get("testBigDecimal")).scale());
-        assertEquals(0, ((List<BigDecimal>) dummy.configuration.get("multiInt")).get(0).scale());
+        assertEquals(0, ((List<BigDecimal>) dummy.configuration.get("multiInt")).getFirst().scale());
         assertEquals(0, ((List<BigDecimal>) dummy.configuration.get("multiInt")).get(1).scale());
         assertEquals(0, ((List<BigDecimal>) dummy.configuration.get("multiInt")).get(2).scale());
-        assertEquals(0, ((BigDecimal) dummy.channels.get(0).configuration.get("testChildLong")).scale());
+        assertEquals(0, ((BigDecimal) dummy.channels.getFirst().configuration.get("testChildLong")).scale());
     }
 
     @Test