Change EventHandler to be generic

src/main/java/org/jeasy/states/api/EventHandler.java

@@ -28,13 +28,13 @@
  *
  * @author Mahmoud Ben Hassine ([email protected])
  */
-public interface EventHandler {
+public interface EventHandler<E extends Event> {
 
     /**
      * Action method to execute when an event occurs.
      * @param event the triggered event
      * @throws Exception thrown if a problem occurs during action performing
      */
-    void handleEvent(AbstractEvent event) throws Exception;
+    void handleEvent(E event) throws Exception;
 
 }

src/main/java/org/jeasy/states/api/FiniteStateMachine.java

@@ -66,7 +66,7 @@ public interface FiniteStateMachine {
      * Return the last triggered event.
      * @return the last triggered event
      */
-    AbstractEvent getLastEvent();
+    Event getLastEvent();
 
     /**
      * Return the last transition made.
@@ -80,6 +80,6 @@ public interface FiniteStateMachine {
      * @return The next FSM state defined by the transition to make
      * @throws FiniteStateMachineException thrown if an exception occurs during event handling
      */
-    State fire(AbstractEvent event) throws FiniteStateMachineException;
+    State fire(Event event) throws FiniteStateMachineException;
 
 }

src/main/java/org/jeasy/states/api/FiniteStateMachineException.java

@@ -39,7 +39,7 @@ public class FiniteStateMachineException extends Exception {
     /**
      * The event triggered when the exception occurred.
      */
-    private AbstractEvent event;
+    private Event event;
 
     /**
      * The root cause of the exception.
@@ -53,7 +53,7 @@ public class FiniteStateMachineException extends Exception {
      * @param event triggered when the exception occurred
      * @param cause root cause of the exception
      */
-    public FiniteStateMachineException(final Transition transition, final AbstractEvent event, final Throwable cause) {
+    public FiniteStateMachineException(final Transition transition, final Event event, final Throwable cause) {
         this.transition = transition;
         this.event = event;
         this.cause = cause;
@@ -71,7 +71,7 @@ public Transition getTransition() {
      * Get the event triggered when the exception occurred.
      * @return the event triggered when the exception occurred.
      */
-    public AbstractEvent getEvent() {
+    public Event getEvent() {
         return event;
     }
 

src/main/java/org/jeasy/states/api/Transition.java

@@ -53,7 +53,7 @@ public interface Transition  {
      * Return fired event type upon which the transition should be made.
      * @return Event type class
      */
-    Class<?> getEventType();
+    Class<? extends Event> getEventType();
 
     /**
      * Return event handler to execute when an event is fired.

src/main/java/org/jeasy/states/core/FiniteStateMachineImpl.java

@@ -39,7 +39,7 @@ final class FiniteStateMachineImpl implements FiniteStateMachine {
     private Set<State> finalStates;
     private Set<State> states;
     private Set<Transition> transitions;
-    private AbstractEvent lastEvent;
+    private Event lastEvent;
     private Transition lastTransition;
 
     FiniteStateMachineImpl(final Set<State> states, final State initialState) {
@@ -54,7 +54,8 @@ final class FiniteStateMachineImpl implements FiniteStateMachine {
      * {@inheritDoc}
      */
     @Override
-    public final synchronized State fire(final AbstractEvent event) throws FiniteStateMachineException {
+    @SuppressWarnings("unchecked")
+    public final synchronized State fire(final Event event) throws FiniteStateMachineException {
 
         if (!finalStates.isEmpty() && finalStates.contains(currentState)) {
             LOGGER.log(Level.WARNING, "FSM is in final state '" + currentState.getName() + "', event " + event + " is ignored.");
@@ -143,7 +144,7 @@ public Set<Transition> getTransitions() {
     }
 
     @Override
-    public AbstractEvent getLastEvent() {
+    public Event getLastEvent() {
         return lastEvent;
     }
 

src/main/java/org/jeasy/states/core/TransitionBuilder.java

@@ -23,6 +23,7 @@
  */
 package org.jeasy.states.core;
 
+import org.jeasy.states.api.Event;
 import org.jeasy.states.api.EventHandler;
 import org.jeasy.states.api.State;
 import org.jeasy.states.api.Transition;
@@ -85,7 +86,7 @@ public TransitionBuilder targetState(final State targetState) {
      * @param eventType of the transition
      * @return FSM transition builder
      */
-    public TransitionBuilder eventType(final Class<?> eventType) {
+    public TransitionBuilder eventType(final Class<? extends Event> eventType) {
         transition.setEventType(eventType);
         return this;
     }
@@ -95,7 +96,7 @@ public TransitionBuilder eventType(final Class<?> eventType) {
      * @param eventHandler of the transition
      * @return FSM transition builder
      */
-    public TransitionBuilder eventHandler(final EventHandler eventHandler) {
+    public <E extends Event> TransitionBuilder eventHandler(final EventHandler<E> eventHandler) {
         transition.setEventHandler(eventHandler);
         return this;
     }

src/main/java/org/jeasy/states/core/TransitionImpl.java

@@ -23,18 +23,19 @@
  */
 package org.jeasy.states.core;
 
+import org.jeasy.states.api.Event;
 import org.jeasy.states.api.EventHandler;
 import org.jeasy.states.api.State;
 import org.jeasy.states.api.Transition;
 import org.jeasy.states.util.Utils;
 
-final class TransitionImpl implements Transition {
+final class TransitionImpl<E extends Event> implements Transition {
 
     private String name;
     private State sourceState;
     private State targetState;
-    private Class<?> eventType;
-    private EventHandler eventHandler;
+    private Class<E> eventType;
+    private EventHandler<E> eventHandler;
 
     public TransitionImpl() {
         name = Utils.DEFAULT_TRANSITION_NAME;
@@ -64,19 +65,19 @@ public void setName(String name) {
         this.name = name;
     }
 
-    public Class<?> getEventType() {
+    public Class<E> getEventType() {
         return eventType;
     }
 
-    public void setEventType(Class<?> eventType) {
+    public void setEventType(Class<E> eventType) {
         this.eventType = eventType;
     }
 
-    public EventHandler getEventHandler() {
+    public EventHandler<? extends Event> getEventHandler() {
         return eventHandler;
     }
 
-    public void setEventHandler(EventHandler eventHandler) {
+    public void setEventHandler(EventHandler<E> eventHandler) {
         this.eventHandler = eventHandler;
     }
 

src/test/java/org/jeasy/states/core/FiniteStateMachineImplTest.java

@@ -46,7 +46,7 @@ public class FiniteStateMachineImplTest {
 
     private State s1, s2;
     @Mock
-    private EventHandler eventHandler;
+    private EventHandler<MoveEvent> eventHandler;
     private FiniteStateMachineImpl stateMachine;
 
     @Before

src/test/java/org/jeasy/states/samples/turnstile/Lock.java

@@ -23,17 +23,15 @@
  */
 package org.jeasy.states.samples.turnstile;
 
-import org.jeasy.states.api.AbstractEvent;
-import org.jeasy.states.api.EventHandler;
-
 import java.util.Date;
 
-class Lock implements EventHandler {
+import org.jeasy.states.api.EventHandler;
 
-    public void handleEvent(AbstractEvent event) throws Exception {
+class Lock implements EventHandler<PushEvent> {
+
+    public void handleEvent(PushEvent event) {
         System.out.println("Notified about event '" + event.getName() + "' triggered at " + new Date(event.getTimestamp()));
         System.out.println("Locking turnstile..");
-
     }
 
 }

src/test/java/org/jeasy/states/samples/turnstile/Unlock.java

@@ -23,14 +23,13 @@
  */
 package org.jeasy.states.samples.turnstile;
 
-import org.jeasy.states.api.AbstractEvent;
-import org.jeasy.states.api.EventHandler;
-
 import java.util.Date;
 
-class Unlock implements EventHandler {
+import org.jeasy.states.api.EventHandler;
+
+class Unlock implements EventHandler<CoinEvent> {
 
-    public void handleEvent(AbstractEvent event) throws Exception {
+    public void handleEvent(CoinEvent event) {
         System.out.println("Notified about event '" + event.getName() + "' triggered at " + new Date(event.getTimestamp()));
         System.out.println("Unlocking turnstile..");
     }