Address Sonar issues in notification UI

This commit addresses a number of bugs and
code smells reported by Sonar in Eclipse Capra's
user interface for notifications.

Change-Id: I6651de1086b0f9587d7cfd2c13be37291a09f3de
diff --git a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/DeleteQuickFix.java b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/DeleteQuickFix.java
index 84494d4..ce146a4 100644
--- a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/DeleteQuickFix.java
+++ b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/DeleteQuickFix.java
@@ -39,7 +39,7 @@
  * @author Michael Warne
  */
 public class DeleteQuickFix implements IMarkerResolution {
-	ArtifactMetaModelAdapter artifactAdapter = ExtensionPointHelper.getArtifactWrapperMetaModelAdapter().get();
+	ArtifactMetaModelAdapter artifactAdapter = ExtensionPointHelper.getArtifactWrapperMetaModelAdapter().orElseThrow();
 
 	private String label;
 
@@ -59,10 +59,11 @@
 		List<Connection> toDelete = new ArrayList<>();
 		List<Connection> toRecreate = new ArrayList<>();
 		EObject artifactToDelete = null;
-		TracePersistenceAdapter tracePersistenceAdapter = ExtensionPointHelper.getTracePersistenceAdapter().get();
+		TracePersistenceAdapter tracePersistenceAdapter = ExtensionPointHelper.getTracePersistenceAdapter()
+				.orElseThrow();
 		EObject traceModel = tracePersistenceAdapter.getTraceModel(resourceSet);
 		TraceHelper traceHelper = new TraceHelper(traceModel);
-		TraceMetaModelAdapter traceMetamodelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().get();
+		TraceMetaModelAdapter traceMetamodelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().orElseThrow();
 		EObject artifactModel = tracePersistenceAdapter.getArtifactWrappers(resourceSet);
 
 		// get all artifacts
@@ -116,8 +117,8 @@
 				// check for all trace links with less than two items
 				if (traceHelper.getTracedElements(c).size() < 2) {
 					toDelete.add(c);
-					}
 				}
+			}
 
 			// Delete the trace links
 			traceMetamodelAdapter.deleteTrace(toDelete, traceModel);
@@ -130,7 +131,7 @@
 	}
 
 	private void recreateTrace(List<Connection> toRecreate, EObject traceModel) {
-		TraceMetaModelAdapter traceMetaModelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().get();
+		TraceMetaModelAdapter traceMetaModelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().orElseThrow();
 		// create a new trace link with the remaining items
 		for (Connection c : toRecreate) {
 			traceMetaModelAdapter.createTrace(c.getTlink().eClass(), traceModel, c.getTargets());
diff --git a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/MarkerResolutionGenerator.java b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/MarkerResolutionGenerator.java
index f3743fd..19e9f73 100644
--- a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/MarkerResolutionGenerator.java
+++ b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/MarkerResolutionGenerator.java
@@ -42,7 +42,7 @@
 				return new IMarkerResolution[] { new DeleteQuickFix("Delete the affected trace link."),
 						new ChangeQuickFix("Do not update existing trace link.") };
 
-			return null;
+			return new IMarkerResolution[0];
 
 		} catch (CoreException e) {
 			return new IMarkerResolution[0];
diff --git a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/RenameOrMoveQuickFix.java b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/RenameOrMoveQuickFix.java
index 0144906..07778e8 100644
--- a/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/RenameOrMoveQuickFix.java
+++ b/bundles/org.eclipse.capra.ui.notification/src/org/eclipse/capra/ui/notification/RenameOrMoveQuickFix.java
@@ -42,7 +42,7 @@
  */
 public class RenameOrMoveQuickFix implements IMarkerResolution {
 
-	ArtifactMetaModelAdapter artifactAdapter = ExtensionPointHelper.getArtifactWrapperMetaModelAdapter().get();
+	ArtifactMetaModelAdapter artifactAdapter = ExtensionPointHelper.getArtifactWrapperMetaModelAdapter().orElseThrow();
 
 	private String label;
 
@@ -58,10 +58,11 @@
 	@Override
 	public void run(IMarker marker) {
 		ResourceSet resourceSet = new ResourceSetImpl();
-		TracePersistenceAdapter tracePersistenceAdapter = ExtensionPointHelper.getTracePersistenceAdapter().get();
+		TracePersistenceAdapter tracePersistenceAdapter = ExtensionPointHelper.getTracePersistenceAdapter()
+				.orElseThrow();
 		EObject traceModel = tracePersistenceAdapter.getTraceModel(resourceSet);
 		EObject artifactModel = tracePersistenceAdapter.getArtifactWrappers(resourceSet);
-		TraceMetaModelAdapter traceMetaModelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().get();
+		TraceMetaModelAdapter traceMetaModelAdapter = ExtensionPointHelper.getTraceMetamodelAdapter().orElseThrow();
 		TraceHelper traceHelper = new TraceHelper(traceModel);
 
 		String artifactContainerFileName = artifactModel.eResource().getURI().lastSegment();
@@ -105,9 +106,7 @@
 		try {
 			resource.save(null);
 			marker.delete();
-		} catch (IOException e) {
-			e.printStackTrace();
-		} catch (CoreException e) {
+		} catch (IOException | CoreException e) {
 			e.printStackTrace();
 		}
 	}