#841 change listener to resource change listener (#846)

* Update Historical Versions (#838)

As per System Requirements mentioned at https://github.com/adobe/aem-project-archetype/tree/master

* #841 move to the recommended ResourceChangeListener

Co-authored-by: Pankaj Parashar <pankajpr@adobe.com>

src/main/archetype/core/src/main/java/core/listeners/SimpleResourceListener.java

@@ -15,35 +15,35 @@
  */
 package ${package}.core.listeners;
 
-import org.apache.sling.api.SlingConstants;
+import java.util.List;
+
+import org.apache.sling.api.resource.observation.ResourceChange;
+import org.apache.sling.api.resource.observation.ResourceChangeListener;
 import org.osgi.service.component.annotations.Component;
 import org.osgi.service.component.propertytypes.ServiceDescription;
-import org.osgi.service.event.Event;
-import org.osgi.service.event.EventConstants;
-import org.osgi.service.event.EventHandler;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * A service to demonstrate how changes in the resource tree
- * can be listened for. It registers an event handler service.
- * The component is activated immediately after the bundle is
- * started through the immediate flag.
+ * can be listened for. 
  * Please note, that apart from EventHandler services,
  * the immediate flag should not be set on a service.
  */
-@Component(service = EventHandler.class,
-           immediate = true,
-           property = {
-                   EventConstants.EVENT_TOPIC + "=org/apache/sling/api/resource/Resource/*"
-           })
+@Component(service = ResourceChangeListener.class,
+           immediate = true
+)
 @ServiceDescription("Demo to listen on changes in the resource tree")
-public class SimpleResourceListener implements EventHandler {
+public class SimpleResourceListener implements ResourceChangeListener {
 
     private final Logger logger = LoggerFactory.getLogger(getClass());
 
-    public void handleEvent(final Event event) {
-        logger.debug("Resource event: {} at: {}", event.getTopic(), event.getProperty(SlingConstants.PROPERTY_PATH));
+    @Override
+    public void onChange(List<ResourceChange> changes) {
+        changes.forEach(change -> {
+            logger.debug("Resource event: {} at: {} isExternal", change.getType(), change.getPath(), change.isExternal());
+        });
+
     }
 }
 

src/main/archetype/core/src/test/java/core/listeners/SimpleResourceListenerTest.java

@@ -15,21 +15,21 @@
  */
 package ${package}.core.listeners;
 
-import java.util.Collections;
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
 import java.util.List;
 
-import org.apache.sling.api.SlingConstants;
+import org.apache.sling.api.resource.observation.ResourceChange;
+import org.apache.sling.api.resource.observation.ResourceChange.ChangeType;
 import org.junit.jupiter.api.Test;
-import org.osgi.service.event.Event;
 
 import uk.org.lidalia.slf4jext.Level;
 import uk.org.lidalia.slf4jtest.LoggingEvent;
 import uk.org.lidalia.slf4jtest.TestLogger;
 import uk.org.lidalia.slf4jtest.TestLoggerFactory;
 
-import static org.junit.jupiter.api.Assertions.assertAll;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 class SimpleResourceListenerTest {
 
     private SimpleResourceListener fixture = new SimpleResourceListener();
@@ -38,19 +38,21 @@ class SimpleResourceListenerTest {
 
     @Test
     void handleEvent() {
-        Event resourceEvent = new Event("event/topic", Collections.singletonMap(SlingConstants.PROPERTY_PATH, "/content/test"));
-
-        fixture.handleEvent(resourceEvent);
+
+        ResourceChange change = new ResourceChange(ChangeType.ADDED,"/content/test", false);
+
+        fixture.onChange(Arrays.asList(change));
 
         List<LoggingEvent> events = logger.getLoggingEvents();
         assertEquals(1, events.size());
         LoggingEvent event = events.get(0);
 
         assertAll(
                 () -> assertEquals(Level.DEBUG, event.getLevel()),
-                () -> assertEquals(2, event.getArguments().size()),
-                () -> assertEquals("event/topic", event.getArguments().get(0)),
-                () -> assertEquals("/content/test", event.getArguments().get(1))
+                () -> assertEquals(3, event.getArguments().size()),
+                () -> assertEquals(ChangeType.ADDED, event.getArguments().get(0)),
+                () -> assertEquals("/content/test", event.getArguments().get(1)),
+                () -> assertEquals(Boolean.FALSE,event.getArguments().get(2))
         );
     }
-}
+}