import java.awt.Graphics;
import java.awt.event.*;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class Game extends JPanel implements KeyListener {
  /* Game Panel class containing all functions */

  /* Global static variables */
  JFrame mainFrame = new JFrame("Falling Blocks");
  int y = 520;
  int[] locations = {0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800};

  /* Global dynamic variables */
  int a; //Horizontal acceleration
  int x;
  boolean needs_repaint;
  boolean on_title_screen, on_game, on_game_over;

  public void init_variables() {
    /* Initates the dynamic variables in order to show Title Screen */
    a = 0;
    x = 0;
    on_title_screen = true;
    on_game = false;
    on_game_over = false;
    needs_repaint = true;
  }

  public void paintComponent(Graphics g) {
    /* Draws the elements on the screen */
    super.paintComponent(g);

    if (on_title_screen) {
      g.drawString("Press SPACE to start game", 10, 10);
      g.drawString("Made by David Gomes", 10, 30);
    }

    else if (on_game) {
      //Draw the player
      g.fillRect(x, y, 50, 50);
    }

    else { //Game Over
      g.drawString("Game Over", 10, 10);
    }

    //Repainting has finished
    needs_repaint = false;
  }

  public Game() {
    /* Defines the frame and the game panel */
    this.setFocusable(true);
    this.addKeyListener(this);

    /* Fixed Layout frame */
    mainFrame.setSize(852, 600);
    mainFrame.setResizable(false);
    mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Add game panel to main frame
    mainFrame.getContentPane().add(this);
  }

  public void run() {
    /* Displays the frame, start the game */
    mainFrame.setVisible(true);
    this.requestFocus();
    init_variables();
  }

  @Override
  public void keyPressed(KeyEvent key) {
    /* Handles key presses */

    if (on_title_screen) {
      /* Start the game when user presses SPACE */
      switch (key.getKeyCode()) {
      case KeyEvent.VK_SPACE:
        on_title_screen = false;
        on_game = true;
        needs_repaint = true;
        break;
      }
    }

    else if (on_game) {
      switch (key.getKeyCode()) {
      case KeyEvent.VK_LEFT:  // Move x coordinate left
        if (x > 0) {
          x -= 50;
          needs_repaint = true;
        }
        break;

      case KeyEvent.VK_RIGHT: // Move x coordinate right
        if (x < 800) {
          x += 50;
          needs_repaint = true;
        }
        break;
      }
    }

    else { // Game Over
      init_variables(); //Go to title screen
      needs_repaint = true;
    }

    // Repaint only if needed
    if (needs_repaint)
      this.repaint();
  }

  /* Game Class is not abstract, and these functions are not needed */
  @Override
  public void keyReleased(KeyEvent arg0) { }
  @Override
  public void keyTyped(KeyEvent arg0) { }
}

I have that code (with syntax highlighting here), and I need to add a timer inside the Game class, associated with a function that runs every N seconds. And I need it to run at the same time as other functions run in the class (keyPressed, paint), etc.

I found a lot of information online on how to make timers in Java (javax.swing.Timer class and other ways), but I don't think it allows me to have the other functions running inside the class too. And I also don't know how to implement it in this specific context.

I appreciate any help, thanks!

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

import java.awt.event.*;

public class Game extends JPanel {
    JFrame mainFrame = new JFrame("Game");

    String[] full_map = {"0101010101",
     "1010101010",
     "0101010101",
     "1010101010",
     "0101010101",
     "1010101010",
     "0101010101",
         "1010101010",
                         "0101010101",
              "1010101010"};

  new Thread(new Runnable() {
    long prevTime = System.currentTimeMillis();
public void run() {
      if (System.currentTimeMillis() >= prevTime+1000*2) {
    prevTime = System.currentTimeMillis();
    System.out.println("hello");
  }
    }
  }).start();

  public void paintComponent(Graphics g) {
    /* Draws the elements on the screen */
    super.paintComponent(g);

    int y, x;
    for (y = 0; y < this.full_map.length; y++) {
      for (x = 0; x < this.full_map[y].length(); x++) {
        if (this.full_map[y].charAt(x) == '1') {
          g.setColor(Color.BLACK);
          g.fillRect(50*x, 50*y, 50, 50);
        }
      }
    }
  }

  public Game() {
    /* Defines the frame and the game panel */
    this.setFocusable(true);
    mainFrame.setSize(this.full_map[0].length()*50, this.full_map.length*50);
    mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    mainFrame.getContentPane().add(this);
  }

  public void start() {
    /* Displays the frame, start the game */
    mainFrame.setVisible(true);
    this.requestFocus();
  }
}
This is my whole code,

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
   Syntax error on token ";", { expected after this token
   Syntax error on token "}", delete this token

   at Game.<init>(Game.java:22)

The Java compiler returned that. I'm not sure of what's wrong, seems like not matching braces, but it all looks correct.

my approach would be to have an instance variable of javax.swing.Timer called timer in the Game class. then in the game constructor:

public Game(){
    //other stuff
    timer = new Timer([MILLISECONDS], new ActionListener(){
        public void actionPerformed(ActionEvent e){
            //run whatever functions you want.
        }});
    timer.start();
}