Completed Double Dispatch example.

Author: iluwatar

double-dispatch/src/main/java/com/iluwatar/App.java

@@ -8,9 +8,17 @@ public class App {
     public static void main( String[] args ) {
     	List<GameObject> objects = new ArrayList<>();
     	objects.add(new FlamingAsteroid(0, 0, 5, 5));
-    	objects.add(new SpaceStationMir(1, 1, 4, 4));
+    	objects.add(new SpaceStationMir(1, 1, 2, 2));
     	objects.add(new Meteoroid(10, 10, 15, 15));
-    	objects.add(new SpaceStationIss(12, 11, 14, 15));
-    	objects.stream().forEach(o1 -> objects.stream().forEach(o2 -> { if (o1 != o2) System.out.println(String.format("%s -> %s", o1, o2)); } ));
+    	objects.add(new SpaceStationIss(12, 12, 14, 14));
+    	
+    	objects.stream().forEach(o -> System.out.println(o));
+    	System.out.println("");
+    	
+    	objects.stream().forEach(o1 -> objects.stream().forEach(o2 -> { if (o1 != o2 && o1.intersectsWith(o2)) o1.collision(o2); } ));
+    	System.out.println("");
+    	
+    	objects.stream().forEach(o -> System.out.println(o));
+    	System.out.println("");
     }
 }

double-dispatch/src/main/java/com/iluwatar/FlamingAsteroid.java

@@ -6,4 +6,9 @@ public FlamingAsteroid(int left, int top, int right, int bottom) {
 		super(left, top, right, bottom);
 		setOnFire(true);
 	}
+
+	@Override
+	public void collision(GameObject gameObject) {
+		gameObject.collisionResolve(this);
+	}
 }

double-dispatch/src/main/java/com/iluwatar/GameObject.java

@@ -30,4 +30,14 @@ public boolean isDamaged() {
 	public void setDamaged(boolean damaged) {
 		this.damaged = damaged;
 	}
+	
+	public abstract void collision(GameObject gameObject);
+	
+	public abstract void collisionResolve(FlamingAsteroid asteroid);
+
+	public abstract void collisionResolve(Meteoroid meteoroid);
+
+	public abstract void collisionResolve(SpaceStationMir mir);
+
+	public abstract void collisionResolve(SpaceStationIss iss);
 }

double-dispatch/src/main/java/com/iluwatar/Meteoroid.java

@@ -5,4 +5,29 @@ public class Meteoroid extends GameObject {
 	public Meteoroid(int left, int top, int right, int bottom) {
 		super(left, top, right, bottom);
 	}
+
+	@Override
+	public void collision(GameObject gameObject) {
+		gameObject.collisionResolve(this);
+	}
+
+	@Override
+	public void collisionResolve(FlamingAsteroid asteroid) {
+		System.out.println(String.format("%s hits %s", asteroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+	}
+
+	@Override
+	public void collisionResolve(Meteoroid meteoroid) {
+		System.out.println(String.format("%s hits %s", meteoroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+	}
+
+	@Override
+	public void collisionResolve(SpaceStationMir mir) {
+		System.out.println(String.format("%s hits %s", mir.getClass().getSimpleName(), this.getClass().getSimpleName()));
+	}
+
+	@Override
+	public void collisionResolve(SpaceStationIss iss) {
+		System.out.println(String.format("%s hits %s", iss.getClass().getSimpleName(), this.getClass().getSimpleName()));
+	}	
 }

double-dispatch/src/main/java/com/iluwatar/SpaceStationIss.java

@@ -5,4 +5,9 @@ public class SpaceStationIss extends SpaceStationMir {
 	public SpaceStationIss(int left, int top, int right, int bottom) {
 		super(left, top, right, bottom);
 	}
+
+	@Override
+	public void collision(GameObject gameObject) {
+		gameObject.collisionResolve(this);
+	}
 }

double-dispatch/src/main/java/com/iluwatar/SpaceStationMir.java

@@ -5,4 +5,34 @@ public class SpaceStationMir extends GameObject {
 	public SpaceStationMir(int left, int top, int right, int bottom) {
 		super(left, top, right, bottom);
 	}
+
+	@Override
+	public void collision(GameObject gameObject) {
+		gameObject.collisionResolve(this);
+	}
+
+	@Override
+	public void collisionResolve(FlamingAsteroid asteroid) {
+		System.out.println(String.format("%s hits %s", asteroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+		setDamaged(true);
+		setOnFire(true);
+	}
+
+	@Override
+	public void collisionResolve(Meteoroid meteoroid) {
+		System.out.println(String.format("%s hits %s", meteoroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+		setDamaged(true);
+	}
+
+	@Override
+	public void collisionResolve(SpaceStationMir mir) {
+		System.out.println(String.format("%s hits %s", mir.getClass().getSimpleName(), this.getClass().getSimpleName()));
+		setDamaged(true);
+	}
+
+	@Override
+	public void collisionResolve(SpaceStationIss iss) {
+		System.out.println(String.format("%s hits %s", iss.getClass().getSimpleName(), this.getClass().getSimpleName()));
+		setDamaged(true);
+	}	
 }