Fixed Findbugs warnings

de.prob.core/src/de/prob/core/Animator.java

@@ -6,18 +6,12 @@
 
 package de.prob.core;
 
-import java.io.BufferedWriter;
 import java.io.File;
-import java.io.FileWriter;
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
 import org.osgi.service.prefs.Preferences;
 
-import com.thoughtworks.xstream.XStream;
-import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
-
 import de.prob.core.command.IComposableCommand;
 import de.prob.core.domainobjects.History;
 import de.prob.core.domainobjects.MachineDescription;
@@ -29,7 +23,6 @@ import de.prob.core.internal.AnimatorImpl;
 import de.prob.core.internal.ServerTraceConnection;
 import de.prob.core.internal.TraceConnectionProvider;
 import de.prob.exceptions.ProBException;
-import de.prob.model.eventb.Model;
 
 
 /**

de.prob.ui/src/de/prob/ui/ltl/CounterExampleTab.java

@@ -275,21 +275,17 @@ public class CounterExampleTab {
 
 	public void zoomIn() {
 		final ZoomManager zoomManager = rootEditPart.getZoomManager();
-		if (zoomManager != null) {
 		if (zoomManager != null && zoomManager.canZoomIn()) {
 			zoomManager.setZoom(zoomManager.getNextZoomLevel());
 		}
 	}
-	}
 
 	public void zoomOut() {
 		final ZoomManager zoomManager = rootEditPart.getZoomManager();
-		if (zoomManager != null) {
 		if (zoomManager != null && zoomManager.canZoomOut()) {
 			zoomManager.setZoom(zoomManager.getPreviousZoomLevel());
 		}
 	}
-	}
 
 	protected void stateChanged(final State activeState,
 			final Operation operation) {

de.prob.ui/src/de/prob/ui/ltl/LtlCheckingDialog.java

@@ -413,7 +413,7 @@ public final class LtlCheckingDialog extends TrayDialog {
 					Logger.notifyUser("Command exception", e);
 				} finally {
 					try {
-						reader.close();
+						if (reader != null) reader.close();
 					} catch (IOException e) {
 						Logger.notifyUser("Unexpected IO exception", e);
 					}