refactoring:

src/main/java/PingPong/Ball.java

@@ -19,6 +19,10 @@ Random random;
         xDirect(randomXDirection);
 
         int randomYDirection = random.nextInt(2);
+        yDirect(randomYDirection);
+    }
+
+    private void yDirect(int randomYDirection) {
         if (randomYDirection == 0)
             randomYDirection--;
         setYDirection(randomYDirection * ballSpeed);