adapt ConfigOptionProvider javadoc to reality (#3761)

...as several implementations return null. Also, it does not make much sense to instantiate empty collections all the time, as the majority of call will be returned with no results. Signed-off-by: Simon Kaufmann <simon.kfm@googlemail.com>
eclipse-archived · Jun 30, 2017 · d3de694 · d3de694
1 parent 9a6b043
commit d3de694
Show file tree

Hide file tree

Showing 3 changed files with 6 additions and 7 deletions.
diff --git a/...ome.config.core/src/main/java/org/eclipse/smarthome/config/core/ConfigOptionProvider.java b/...ome.config.core/src/main/java/org/eclipse/smarthome/config/core/ConfigOptionProvider.java
@@ -28,8 +28,7 @@ public interface ConfigOptionProvider {
      *            the parameter name for which the requested options shall be returned
      * @param locale
      *            locale
-     * @return the configuration options provided by this provider (not
-     *         null, could be empty)
+     * @return the configuration options provided by this provider if any or {@code null} otherwise
      */
     Collection<ParameterOption> getParameterOptions(URI uri, String param, Locale locale);
 }
diff --git a/.../java/org/eclipse/smarthome/core/persistence/internal/PersistenceServiceRegistryImpl.java b/.../java/org/eclipse/smarthome/core/persistence/internal/PersistenceServiceRegistryImpl.java
@@ -89,13 +89,14 @@ public Set<PersistenceService> getAll() {
 
     @Override
     public Collection<ParameterOption> getParameterOptions(URI uri, String param, Locale locale) {
-        Set<ParameterOption> options = new HashSet<>();
         if (uri.toString().equals("system:persistence") && param.equals("default")) {
+            Set<ParameterOption> options = new HashSet<>();
             for (PersistenceService service : getAll()) {
                 options.add(new ParameterOption(service.getId(), service.getLabel(locale)));
             }
+            return options;
         }
-        return options;
+        return null;
     }
 
 }
diff --git a/...me.magic/src/main/java/org/eclipse/smarthome/magic/binding/internal/MagicServiceImpl.java b/...me.magic/src/main/java/org/eclipse/smarthome/magic/binding/internal/MagicServiceImpl.java
@@ -11,7 +11,6 @@
 import java.math.BigDecimal;
 import java.net.URI;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Locale;
 
 import org.eclipse.smarthome.config.core.ParameterOption;
@@ -26,7 +25,7 @@ public class MagicServiceImpl implements MagicService {
     @Override
     public Collection<ParameterOption> getParameterOptions(URI uri, String param, Locale locale) {
         if (!uri.equals(CONFIG_URI)) {
-            return Collections.emptyList();
+            return null;
         }
 
         if (param.equals(PARAMETER_BACKEND_DECIMAL)) {
@@ -35,7 +34,7 @@ public Collection<ParameterOption> getParameterOptions(URI uri, String param, Lo
                     new ParameterOption(BigDecimal.valueOf(21d).toPlainString(), "21"));
         }
 
-        return Collections.emptyList();
+        return null;
     }
 
 }