Simplify adding elements to Collections (#4006)

* Simplify adding elements to Collections

This optimizes and simplifies the code that adds elements to Collections.

Signed-off-by: Wouter Born <github@maindrain.net>

bundles/org.openhab.core.automation.module.script.rulesupport/src/main/java/org/openhab/core/automation/module/script/rulesupport/shared/ScriptedAutomationManager.java

@@ -164,8 +164,7 @@ public class ScriptedAutomationManager {
             // triggers are optional
         }
 
-        List<Action> actions = new ArrayList<>();
-        actions.addAll(element.getActions());
+        List<Action> actions = new ArrayList<>(element.getActions());
 
         if (element instanceof SimpleRuleActionHandler handler) {
             String privId = addPrivateActionHandler(new SimpleRuleActionHandlerDelegate(handler));

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/RulePredicates.java

@@ -87,9 +87,7 @@ public class RulePredicates {
      */
     public static Predicate<Rule> hasAnyOfPrefixes(String... prefixes) {
         final HashSet<String> namespaceSet = new HashSet<>(prefixes.length);
-        for (final String namespace : prefixes) {
-            namespaceSet.add(namespace);
-        }
+        namespaceSet.addAll(Arrays.asList(prefixes));
 
         // this will even work for null namespace
         return r -> namespaceSet.contains(getPrefix(r));

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

@@ -396,8 +396,8 @@ public class Printer {
         int[] columnWidths = new int[] { COLUMN_PROPERTY_VALUE };
         List<String> columnValues = new ArrayList<>();
         columnValues.add(module.getId());
-        List<String> moduleContent = new ArrayList<>();
-        moduleContent.addAll(Utils.getTableTitle(Utils.getRow(columnWidths, columnValues), COLUMN_PROPERTY_VALUE));
+        List<String> moduleContent = new ArrayList<>(
+                Utils.getTableTitle(Utils.getRow(columnWidths, columnValues), COLUMN_PROPERTY_VALUE));
 
         columnWidths = new int[] { COLUMN_CONFIG_PARAMETER, COLUMN_CONFIG_PARAMETER_VALUE };
         columnValues.set(0, ID);

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

@@ -126,12 +126,7 @@ public class ConfigDescriptionRegistry {
         }
 
         // Now convert the map into the collection
-        Collection<ConfigDescription> configDescriptions = new ArrayList<>(configMap.size());
-        for (ConfigDescription configDescription : configMap.values()) {
-            configDescriptions.add(configDescription);
-        }
-
-        return Collections.unmodifiableCollection(configDescriptions);
+        return Collections.unmodifiableCollection(new ArrayList<>(configMap.values()));
     }
 
     /**
@@ -245,10 +240,8 @@ public class ConfigDescriptionRegistry {
      */
     private ConfigDescriptionParameter getConfigOptions(URI uri, Set<URI> aliases, ConfigDescriptionParameter parameter,
             @Nullable Locale locale) {
-        List<ParameterOption> options = new ArrayList<>();
-
         // Add all the existing options that may be provided by the initial config description provider
-        options.addAll(parameter.getOptions());
+        List<ParameterOption> options = new ArrayList<>(parameter.getOptions());
 
         boolean found = fillFromProviders(uri, parameter, locale, options);
 

bundles/org.openhab.core.config.core/src/main/java/org/openhab/core/config/core/internal/metadata/MetadataConfigDescriptionProviderImpl.java

@@ -71,9 +71,7 @@ public class MetadataConfigDescriptionProviderImpl implements ConfigDescriptionP
 
     @Override
     public Collection<ConfigDescription> getConfigDescriptions(@Nullable Locale locale) {
-        List<ConfigDescription> ret = new LinkedList<>();
-        ret.addAll(getValueConfigDescriptions(locale));
-        return ret;
+        return new LinkedList<>(getValueConfigDescriptions(locale));
     }
 
     @Override

bundles/org.openhab.core.io.console.eclipse/src/main/java/org/openhab/core/io/console/eclipse/internal/ConsoleSupportEclipse.java

@@ -17,7 +17,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
 
@@ -64,9 +63,7 @@ public class ConsoleSupportEclipse implements CommandProvider {
     }
 
     private Collection<ConsoleCommandExtension> getConsoleCommandExtensions() {
-        final Set<ConsoleCommandExtension> set = new HashSet<>();
-        set.addAll(consoleCommandExtensions.values());
-        return set;
+        return new HashSet<>(consoleCommandExtensions.values());
     }
 
     /**

bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/channel/ChannelTypeResource.java

@@ -175,9 +175,7 @@ public class ChannelTypeResource implements RESTResource {
         for (ProfileType profileType : profileTypeRegistry.getProfileTypes()) {
             if (profileType instanceof TriggerProfileType type) {
                 if (type.getSupportedChannelTypeUIDs().contains(ctUID)) {
-                    for (String itemType : profileType.getSupportedItemTypes()) {
-                        result.add(itemType);
-                    }
+                    result.addAll(profileType.getSupportedItemTypes());
                 }
             }
         }

bundles/org.openhab.core/src/main/java/org/openhab/core/cache/ExpiringCacheMap.java

@@ -175,11 +175,7 @@ public class ExpiringCacheMap<K, V> {
      * @return the set of all keys
      */
     public synchronized Set<K> keys() {
-        final Set<K> keys = new LinkedHashSet<>();
-        for (final K key : items.keySet()) {
-            keys.add(key);
-        }
-        return keys;
+        return new LinkedHashSet<>(items.keySet());
     }
 
     /**

bundles/org.openhab.core/src/main/java/org/openhab/core/internal/i18n/ResourceBundleTracker.java

@@ -13,6 +13,7 @@
 package org.openhab.core.internal.i18n;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -127,9 +128,7 @@ public class ResourceBundleTracker extends BundleTracker {
         List<Bundle> hosts = new ArrayList<>();
         Bundle[] bundles = pkgAdmin.getHosts(fragment);
         if (bundles != null) {
-            for (int i = 0; i < bundles.length; i++) {
-                hosts.add(bundles[i]);
-            }
+            hosts.addAll(Arrays.asList(bundles));
         }
         return hosts;
     }