Index: src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilter.java
===================================================================
--- src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilter.java	(revision 44111)
+++ src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilter.java	(working copy)
@@ -41,6 +41,7 @@
 import org.eclipse.jdt.core.ElementChangedEvent;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaElementDelta;
+import org.eclipse.jdt.core.IPackageFragmentRoot;
 import org.jboss.tools.ws.jaxrs.core.internal.utils.ConstantUtils;
 import org.jboss.tools.ws.jaxrs.core.internal.utils.Logger;
 import org.jboss.tools.ws.jaxrs.core.jdt.JdtUtils;
@@ -124,7 +125,8 @@
 		IJavaElement element = event.getElement();
 		// prevent processing java elements in a closed java project
 		// prevent processing of any file named 'package-info.java'
-		if (isProjectClosed(element) || isPackageInfoFile(element)) {
+		// prevent processing of any jar file
+		if (isProjectClosed(element) || isPackageInfoFile(element) || isJarArchive(element)) {
 			return false;
 		}
 		int flags = event.getFlags();
@@ -142,6 +144,16 @@
 	}
 
 	/**
+	 * 
+	 * @param element
+	 * @return true if the given java element is a Jar archive.
+	 */
+	private boolean isJarArchive(IJavaElement element) {
+		return (element.getElementType() == IJavaElement.PACKAGE_FRAGMENT_ROOT && ((IPackageFragmentRoot)element).isArchive());
+            
+	}
+
+	/**
 	 * Returns true if the element resource is a file named 'package-info.java' (whatever the containing folder)
 	 * @param element
 	 * @return
Index: src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilterTestCase.java
===================================================================
--- src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilterTestCase.java	(revision 43939)
+++ src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaFilterTestCase.java	(working copy)
@@ -13,7 +13,7 @@
 import static org.eclipse.core.resources.IResourceDelta.REMOVED;
 import static org.eclipse.jdt.core.ElementChangedEvent.POST_CHANGE;
 import static org.eclipse.jdt.core.ElementChangedEvent.POST_RECONCILE;
-import static org.eclipse.jdt.core.IJavaElement.ANNOTATION;
+import static org.eclipse.jdt.core.IJavaElement.*;
 import static org.eclipse.jdt.core.IJavaElement.COMPILATION_UNIT;
 import static org.eclipse.jdt.core.IJavaElement.METHOD;
 import static org.eclipse.jdt.core.IJavaElement.TYPE;
@@ -30,6 +30,7 @@
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IMethod;
+import org.eclipse.jdt.core.IPackageFragmentRoot;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.JavaModelException;
 import org.junit.Before;
@@ -117,4 +118,18 @@
 		assertFalse("Wrong result", filter.apply(createEvent(element, REMOVED, POST_CHANGE, NO_FLAG)));
 	}
 
+	@Test
+	public void shouldNotAcceptChangesInJarFile() {
+		IPackageFragmentRoot element = createMock(IPackageFragmentRoot.class, PACKAGE_FRAGMENT_ROOT);
+		IResource resource = mock(IResource.class);
+		when(element.getResource()).thenReturn(resource);
+		when(element.isArchive()).thenReturn(true);
+		when(resource.getType()).thenReturn(IResource.FILE);
+		assertFalse("Wrong result", filter.apply(createEvent(element, ADDED, POST_RECONCILE, NO_FLAG)));
+		assertFalse("Wrong result", filter.apply(createEvent(element, ADDED, POST_CHANGE, NO_FLAG)));
+		assertFalse("Wrong result", filter.apply(createEvent(element, CHANGED, POST_RECONCILE, NO_FLAG)));
+		assertFalse("Wrong result", filter.apply(createEvent(element, CHANGED, POST_CHANGE, NO_FLAG)));
+		assertFalse("Wrong result", filter.apply(createEvent(element, REMOVED, POST_RECONCILE, NO_FLAG)));
+		assertFalse("Wrong result", filter.apply(createEvent(element, REMOVED, POST_CHANGE, NO_FLAG)));
+	}
 }
Index: src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaScannerTestCase.java
===================================================================
--- src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaScannerTestCase.java	(revision 44469)
+++ src/org/jboss/tools/ws/jaxrs/core/internal/metamodel/builder/JavaElementDeltaScannerTestCase.java	(working copy)
@@ -549,12 +549,12 @@
 	}
 
 	@Test
-	public void shouldNotifyWhenLibraryAddedInClasspath() throws CoreException, InterruptedException {
+	public void shouldNotNotifyWhenLibraryAddedInClasspath() throws CoreException, InterruptedException {
 		// operation
 		IPackageFragmentRoot addedEntry = WorkbenchTasks.addClasspathEntry(javaProject, "slf4j-api-1.5.2.jar",
 				new NullProgressMonitor());
 		// verifications
-		verifyEventNotification(addedEntry, ADDED, POST_CHANGE, NO_FLAG, times(1));
+		verifyEventNotification(addedEntry, ADDED, POST_CHANGE, NO_FLAG, times(0));
 	}
 
 	@Test
@@ -567,13 +567,13 @@
 	}
 
 	@Test
-	public void shouldNotifyWhenLibraryRemovedFromClasspath() throws CoreException, InterruptedException {
+	public void shouldNotNotifyWhenLibraryRemovedFromClasspath() throws CoreException, InterruptedException {
 		// operation
 		List<IPackageFragmentRoot> removedEntries = WorkbenchUtils.removeClasspathEntry(javaProject,
 				"jaxrs-api-2.0.1.GA.jar", null);
 		// verifications
 		for (IPackageFragmentRoot removedEntry : removedEntries) {
-			verifyEventNotification(removedEntry, REMOVED, POST_CHANGE, F_REMOVED_FROM_CLASSPATH, times(1));
+			verifyEventNotification(removedEntry, REMOVED, POST_CHANGE, F_REMOVED_FROM_CLASSPATH, times(0));
 		}
 	}