how to open one Jframe from main method call

See more:

Java

Swing

I have downloaded a snake game project in java. Initially the project contains three java files i.e "

Engine.java

Snake.java

GameBoard.java

And Engine.java have the main() method, when i run this Engine.java class game starts running.

And to improve the user iteractivity i have created two JFrames :"PlayGame.java", Rules.java

Now this project having five java classes in this project-

Engine.java(containing main() method)
Snake.java
GameBoard.java
PlayGame.java(is a JFrame)
Rules.java(is a JFrame)

PlayGame.java have three buttons

Play - i want when play button getclicked snake game start/run.
Rules - when clicked Rules.java Jframe should be opened
Exit - exits the application

Now what i want is at first "PlayGame.java" JFrame should appear and throw this game should start i.e when i click play button game should start But problem i am facing is "playGame.java" JFrame and "game screen" appearing at the same time .thats what i don't want in my project

Here is the code that i have included in main method

public static void main(String[] args) {
    new PlayGame().setVisible(true);

    JFrame frame = new JFrame("SnakeGame");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setResizable(false);

    Canvas canvas = new Canvas();
    canvas.setBackground(Color.black);
    canvas.setPreferredSize(new Dimension(GameBoard.MAP_SIZE *GameBoard.TILE_SIZE,GameBoard.MAP_SIZE * GameBoard.TILE_SIZE));

    frame.add(canvas);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true); 

    new Engine(canvas).startGame();

         }

Here is the startGame() method which is in Engine.java class

public void startGame() {
		canvas.createBufferStrategy(2);
		
		Graphics2D g = (Graphics2D)canvas.getBufferStrategy().getDrawGraphics();
		g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		
		long start = 0L;
		long sleepDuration = 0L;
		while(true) {
			start = System.currentTimeMillis();

			update();
			render(g);

			canvas.getBufferStrategy().show();

			g.clearRect(0, 0, canvas.getWidth(), canvas.getHeight());
			
			sleepDuration = (1500L / UPDATES_PER_SECOND) - (System.currentTimeMillis() - start);

			if(sleepDuration > 0) {
				try {
					Thread.sleep(sleepDuration);
				} catch(Exception e) {
					e.printStackTrace();
				}
			}
		}
	}