src/Board.java

@@ -13,7 +13,7 @@ public class Board {
 		this.createShip(size - 13);
 	}
 
-	public HitResponse hit (Point point){
+	public synchronized HitResponse hit (Point point){
 		HitResponse response = new HitResponse(HitResponseType.MISS,point);
 		for (int i = 0; i < this.ships.size(); i++) {
 			HitResponseType type = this.ships.get(i).shootOnShip(point);
@@ -50,7 +50,7 @@ public class Board {
 		return ships;
 	}
 
-	public boolean addHits(HitResponse hitResponse) {
+	public synchronized boolean addHits(HitResponse hitResponse) {
 		if (this.getHitResponsOnPoint(hitResponse.getPoint()) == null){
 			this.hits.add(hitResponse);
 			return true;
@@ -58,7 +58,7 @@ public class Board {
 		return false;
 	}
 
-	public HitResponse getHitResponsOnPoint(Point point) {
+	public synchronized HitResponse getHitResponsOnPoint(Point point) {
 		for (int i = 0; i < this.hits.size(); i++){
 			if (this.hits.get(i).getPoint().equals(point)){
 				return this.hits.get(i);

src/Player.java

@@ -13,7 +13,7 @@ public abstract class Player {
         this.board = new Board(size);
     }
 
-    public void receiveShoot(Point point) {
+    public synchronized void receiveShoot(Point point) {
         HitResponse hitResponse = board.getHitResponsOnPoint(point);
         if (!(hitResponse == null)){
             enemy.receiveHit(hitResponse);
@@ -22,7 +22,7 @@ public abstract class Player {
         }
     }
 
-    public void receiveHit(HitResponse hitResponse) {
+    public synchronized void receiveHit(HitResponse hitResponse) {
         enemy.board.addHits(hitResponse);
     }