Fixes a bunch of compiler and PMD warnings (#820)

core/src/main/java/edu/wpi/grip/core/operations/network/NetworkPublisher.java

@@ -65,5 +65,6 @@ protected final void checkNamePresent() {
   /**
    * Close the network publisher. This should not throw an exception.
    */
+  @Override
   public abstract void close();
 }

core/src/main/java/edu/wpi/grip/core/operations/network/NetworkReceiver.java

@@ -39,7 +39,8 @@ public NetworkReceiver(String path) {
   public abstract void addListener(Consumer<Object> consumer);
 
   /**
-   * Close the network reciever. This should not throw an exception.
+   * Close the network receiver. This should not throw an exception.
    */
+  @Override
   public abstract void close();
 }

core/src/main/java/edu/wpi/grip/core/sockets/InputSocket.java

@@ -25,6 +25,7 @@ public interface InputSocket<T> extends Socket<T> {
   /**
    * Should be only called by parent classes.
    */
+  @Override
   void onValueChanged();
 
   interface Factory {

core/src/main/java/edu/wpi/grip/core/sockets/SocketHints.java

@@ -26,10 +26,10 @@ private SocketHints() { /* no op */ }
   @SuppressWarnings("unchecked")
   public static <T extends Enum<T>> SocketHint<T> createEnumSocketHint(final String identifier,
                                                                        final T defaultValue) {
-    return new SocketHint.Builder(defaultValue.getClass())
+    return new SocketHint.Builder(defaultValue.getDeclaringClass())
         .identifier(identifier).initialValue(defaultValue)
         .view(SocketHint.View.SELECT)
-        .domain(defaultValue.getClass().getEnumConstants()).build();
+        .domain(defaultValue.getDeclaringClass().getEnumConstants()).build();
   }
 
   public static SocketHint<Number> createNumberSocketHint(

ui/src/main/java/edu/wpi/grip/ui/Main.java

@@ -164,6 +164,7 @@ public void start(Stage stage) throws IOException {
     }
   }
 
+  @Override
   public void stop() {
     SafeShutdown.flagStopping();
   }

ui/src/main/java/edu/wpi/grip/ui/OperationController.java

@@ -86,6 +86,7 @@ public void addStep() {
     this.pipeline.addStep(stepFactory.create(operationMetaData));
   }
 
+  @Override
   public GridPane getRoot() {
     return root;
   }

ui/src/main/java/edu/wpi/grip/ui/pipeline/StepController.java

@@ -183,6 +183,7 @@ public Collection<OutputSocketController> getOutputSockets() {
     return outputSocketMapManager.keySet();
   }
 
+  @Override
   public VBox getRoot() {
     return root;
   }

ui/src/main/java/edu/wpi/grip/ui/pipeline/input/NumberSpinnerInputSocketController.java

@@ -54,6 +54,7 @@ public class NumberSpinnerInputSocketController extends InputSocketController<Nu
   }
 
   @FXML
+  @Override
   protected void initialize() {
     super.initialize();
     final Spinner<Double> spinner = new Spinner<>(this.valueFactory);

ui/src/main/java/edu/wpi/grip/ui/pipeline/source/CameraSourceController.java

@@ -31,6 +31,7 @@ public final class CameraSourceController extends SourceController<CameraSource>
   }
 
   @FXML
+  @Override
   public void initialize() throws Exception {
     super.initialize();
     addControls(startStoppableButtonFactory.create(getSource()));

ui/src/main/java/edu/wpi/grip/ui/pipeline/source/SourceController.java

@@ -91,6 +91,7 @@ public Collection<OutputSocketController> getOutputSockets() {
     return this.outputSocketMapManager.keySet();
   }
 
+  @Override
   public VBox getRoot() {
     return root;
   }