Snake Game : Java

   Snake Game is a game in which the player controls a snake, which roams around on a bordered plane. The goal is to score points by helping the snake eat its food, while preventing a collision with the walls or its own tail.

Each time the snake eats a piece of food, its tail grows longer, making the game increasingly difficult. The user controls the direction of the snake's head (up, down, left, or right), and the snake's body follows. The longer you play and the more food the snake eats, the more points you gain. It has been developed in Java.

 

Screenshots

 

 

Source Code

 

Snake.java

/* * Title : Snake Game * Author : Manish Kumar * Blog : www.justdocodings.blogspot.com */ import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.util.Random; public class Snake extends JPanel implements ActionListener { static final int SCREEN_WIDTH = 500; static final int SCREEN_HEIGHT = 550; static final int SCREEN = 500; static final int IMAGE_SIZE = 25; static final int GAME_UNITS = (SCREEN * SCREEN) / (IMAGE_SIZE * IMAGE_SIZE); static final int DELAY = 175; static final int HORIZONTAL = 1; static final int VERTICAL = 2; static final int UPPERBOUND = (SCREEN/IMAGE_SIZE)-2; static final int UNIT = SCREEN/IMAGE_SIZE; //Arrays final int snk_x[] = new int[GAME_UNITS]; final int snk_y[] = new int[GAME_UNITS]; final int block_x[] = new int[GAME_UNITS]; final int block_y[] = new int[GAME_UNITS]; // int snakeLength = 4; int foodEaten=0; int level = 1; int nblock = 0; int foodX; int foodY; char direction = 'L'; boolean running = false; boolean pause = false; Timer timer; Random random; Image food; Image body; Image headL,headR,headU,headD; Image tile; /// // menubar static JMenuBar mb; // JMenu static JMenu lvl,help; // CheckBoxMenu items static JRadioButtonMenuItem l1, l2, l3, l4, l5, l6; static JMenuItem abt,hlp; Snake() { addKeyListener(new SAdapter()); setBackground(Color.cyan); setFocusable(true); setPreferredSize(new Dimension(SCREEN_WIDTH, SCREEN_HEIGHT)); loadImage(); startGame(); addMenu(); } public void addMenu() { // create a menubar mb = new JMenuBar(); // create a menu lvl = new JMenu("Level"); help = new JMenu("Help"); l1 = new JRadioButtonMenuItem("Level 1",true); l2 = new JRadioButtonMenuItem("Level 2",false); l3 = new JRadioButtonMenuItem("Level 3",false); l4 = new JRadioButtonMenuItem("Level 4",false); l5 = new JRadioButtonMenuItem("Level 5",false); l6 = new JRadioButtonMenuItem("Level 6",false); hlp = new JMenuItem("View Help"); abt = new JMenuItem("About"); l1.setActionCommand("levelOne"); l2.setActionCommand("levelTwo"); l3.setActionCommand("levelThree"); l4.setActionCommand("levelFour"); l5.setActionCommand("levelFive"); l6.setActionCommand("levelSix"); hlp.setActionCommand("viewHelp"); abt.setActionCommand("about"); // Group the Radio Button Menu ButtonGroup group = new ButtonGroup(); group.add(l1); group.add(l2); group.add(l3); group.add(l4); group.add(l5); group.add(l6); l1.addActionListener(this); l2.addActionListener(this); l3.addActionListener(this); l4.addActionListener(this); l5.addActionListener(this); l6.addActionListener(this); hlp.addActionListener(this); abt.addActionListener(this); // add menu items to menu lvl.add(l1); lvl.add(l2); lvl.add(l3); lvl.add(l4); lvl.add(l5); lvl.add(l6); help.add(hlp); help.add(abt); // add menu to menu bar mb.add(lvl); mb.add(help); } public void startGame() { level(); initPosSnake(5,10); newFood(); running = true; timer = new Timer(DELAY, this); timer.start(); } public void reset() { direction='L'; snakeLength=4; foodEaten=0; for(int i=0;i<=nblock;i++) { block_x[i]=0; block_y[i]=0; } nblock=0; initPosSnake(5,10); if(running == false) { running=true; timer.start(); } } public void level(){ if(level==1) { } else if(level==2) { plotBrick(0,0,HORIZONTAL,UNIT); plotBrick(0,UNIT-1,HORIZONTAL,UNIT); } else if(level==3) { plotBrick(3,3,HORIZONTAL,UNIT-7); plotBrick(3,UNIT-4,HORIZONTAL,UNIT-7); } else if(level==4) { plotBrick(3,2,HORIZONTAL,3); plotBrick(3,3,VERTICAL,2); plotBrick(UNIT-7,UNIT-2,HORIZONTAL,3); plotBrick(UNIT-5,UNIT-4,VERTICAL,2); } else if(level==5) { plotBrick(3,2,HORIZONTAL,3); plotBrick(3,3,VERTICAL,2); plotBrick(3,UNIT-2,HORIZONTAL,3); plotBrick(3,UNIT-4,VERTICAL,2); plotBrick(UNIT-7,2,HORIZONTAL,3); plotBrick(UNIT-5,3,VERTICAL,2); plotBrick(UNIT-7,UNIT-2,HORIZONTAL,3); plotBrick(UNIT-5,UNIT-4,VERTICAL,2); } else if(level==6) { plotBrick(0,0,HORIZONTAL,UNIT); plotBrick(0,UNIT-1,HORIZONTAL,UNIT); plotBrick(0,1,VERTICAL,6); plotBrick(UNIT-1,1,VERTICAL,6); plotBrick(0,13,VERTICAL,6); plotBrick(UNIT-1,13,VERTICAL,6); } } public void initPosSnake(int x, int y) { for (int i = snakeLength-1; i>=0; i--) { snk_x[i] = x - i; snk_y[i] = y; } } public void loadImage() { ImageIcon imgtile = new ImageIcon("tile.png"); tile = imgtile.getImage(); ImageIcon imgbody = new ImageIcon("body.png"); body = imgbody.getImage(); ImageIcon imgheadL = new ImageIcon("headL.png"); headL = imgheadL.getImage(); ImageIcon imgheadR = new ImageIcon("headR.png"); headR = imgheadR.getImage(); ImageIcon imgheadU = new ImageIcon("headU.png"); headU = imgheadU.getImage(); ImageIcon imgheadD = new ImageIcon("headD.png"); headD = imgheadD.getImage(); ImageIcon imgfood = new ImageIcon("apple.png"); food = imgfood.getImage(); } public void doDrawings(Graphics g) { if(running) { //food g.drawImage(food,foodX*IMAGE_SIZE,foodY*IMAGE_SIZE,this); //brick for(int k=0;k<nblock;k++) g.drawImage(tile,block_x[k]*IMAGE_SIZE,block_y[k]*IMAGE_SIZE,this); //head switch(direction) { case 'L': g.drawImage(headL,snk_x[0]*IMAGE_SIZE,snk_y[0]*IMAGE_SIZE,this); break; case 'R': g.drawImage(headR,snk_x[0]*IMAGE_SIZE,snk_y[0]*IMAGE_SIZE,this); break; case 'U': g.drawImage(headU,snk_x[0]*IMAGE_SIZE,snk_y[0]*IMAGE_SIZE,this); break; case 'D': g.drawImage(headD,snk_x[0]*IMAGE_SIZE,snk_y[0]*IMAGE_SIZE,this); break; } //body for(int i=snakeLength-1;i>0;i--) g.drawImage(body,snk_x[i]*IMAGE_SIZE,snk_y[i]*IMAGE_SIZE,this); showScore(g); Toolkit.getDefaultToolkit().sync(); } else { gameOver(g); } } @Override public void paintComponent(Graphics g) { super.paintComponent(g); doDrawings(g); } public void gameOver(Graphics g) { //Score g.setColor(Color.blue); g.setFont(new Font("Ink Free", Font.BOLD, 30)); FontMetrics metrics1 = getFontMetrics(g.getFont()); g.drawString("Score: " + foodEaten, (SCREEN_WIDTH - metrics1.stringWidth("Score: " + foodEaten)) / 2, g.getFont().getSize()+50); //Game Over text g.setColor(Color.red); g.setFont(new Font("Ink Free", Font.BOLD, 45)); FontMetrics metrics2 = getFontMetrics(g.getFont()); g.drawString("Game Over", (SCREEN_WIDTH - metrics2.stringWidth("Game Over")) / 2, SCREEN_HEIGHT / 2); } public void showScore(Graphics g) { //Score g.drawRect(0,SCREEN,SCREEN_WIDTH,SCREEN_HEIGHT); g.setColor(Color.green); g.fillRect(0,SCREEN,SCREEN_WIDTH,SCREEN_HEIGHT); g.setColor(Color.red); g.setFont(new Font("Ink Free", Font.BOLD,15)); g.drawString("Score: "+ foodEaten,100,SCREEN_HEIGHT-30); g.drawString("Level: "+ level,SCREEN_WIDTH-200,SCREEN_HEIGHT-30); } public void newFood() { random = new Random(); foodX = random.nextInt(UPPERBOUND)+1; foodY = random.nextInt(UPPERBOUND)+1; // Check if food is placed on brick if(nblock>0) { for(int i=0;i<nblock;i++) if(foodX==block_x[i]&&foodY==block_y[i]) newFood(); } } public void checkFood() { if(snk_x[0]==foodX && snk_y[0]==foodY) { foodEaten++; newFood(); snakeLength++; move(); } } public void isSnkHitItself() { for(int i=snakeLength-1;i>2;i--) { if(snk_x[0]==snk_x[i]&&snk_y[0]==snk_y[i]) { running = false; } } if(!running) timer.stop(); } public void isSnakeHitBrick() { for(int i=0;i<nblock;i++) { if(block_x[i]==snk_x[0]&&block_y[i]==snk_y[0]) running = false; } if(!running) timer.stop(); } public void plotBrick(int start_x, int start_y,int dir, int howmany) { if(dir==HORIZONTAL) { for(int i=0;i<howmany;i++) { block_x[nblock]=start_x+i; block_y[nblock]=start_y; nblock++; } } else if(dir==VERTICAL) { for(int j=0;j<howmany;j++) { block_x[nblock]=start_x; block_y[nblock]=start_y+j; nblock++; } } } public void checkCollision() { if(snk_x[0]<0) snk_x[0]=UNIT; if(snk_x[0]>UNIT) snk_x[0]=0; if(snk_y[0]<0) snk_y[0]=UNIT; if(snk_y[0]>UNIT) snk_y[0]=0; } @Override public void actionPerformed(ActionEvent e) { String s = e.getActionCommand(); if(s!=null) { switch(s) { case "levelOne" : level=1; reset(); level(); break; case "levelTwo" : level=2; reset(); level(); break; case "levelThree" : level=3; reset(); level(); break; case "levelFour" : level=4; reset(); level(); break; case "levelFive" : level=5; reset(); level(); break; case "levelSix" : level=6; reset(); level(); break; case "about" : JOptionPane.showMessageDialog(this,"Title : Snake Game \n Author : Manish Kumar \n Blog : www.justdocodings.blopspot.com","About", JOptionPane.INFORMATION_MESSAGE); break; case "viewHelp" : JOptionPane.showMessageDialog(this,"Use arrow keys for movement \n and space key to pause game.","Help",JOptionPane.INFORMATION_MESSAGE); break; } } if (running) { move(); checkFood(); checkCollision(); isSnkHitItself(); isSnakeHitBrick(); } repaint(); } public void move() { for (int i = snakeLength-1; i>0; i--) { snk_x[i] = snk_x[i - 1]; snk_y[i] = snk_y[i - 1]; } switch (direction) { case 'U': snk_y[0]--; break; case 'D': snk_y[0]++; break; case 'L': snk_x[0]--; break; case 'R': snk_x[0]++; break; } } public class SAdapter extends KeyAdapter { @Override public void keyPressed(KeyEvent e) { switch (e.getKeyCode()) { case KeyEvent.VK_LEFT: if(direction!='R') direction='L'; break; case KeyEvent.VK_RIGHT: if(direction!='L') direction='R'; break; case KeyEvent.VK_UP: if(direction!='D') direction='U'; break; case KeyEvent.VK_DOWN: if(direction!='U') direction='D'; break; case KeyEvent.VK_SPACE: if(pause==false) { timer.stop(); pause = true; } else if(pause==true) { timer.start(); pause=false; } break; } } } }

SnakeFrame.java

/* * Title : Snake Game * Author : Manish Kumar * Blog : www.justdocodings.blogspot.com */ //import java.awt.EventQueue; import javax.swing.*; public class SnakeFrame extends JFrame { public SnakeFrame() { add(new Snake()); setResizable(false); pack(); setTitle("Snake"); setLocationRelativeTo(null); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public static void main(String[] args) { //EventQueue.invokeLater(new Runnable() { //@Override //public void run() { JFrame jf = new SnakeFrame(); jf.setJMenuBar(Snake.mb); jf.setVisible(true); //} //}); } }

Functionality

• To move the snake left, press Left arrow key.

• To move the snake right, press Right arrow key.

• To move the snake up, press Up arrow key.

• To move the snake down, press Down arrow key.

• To pause the game, press Space bar key.

Downloads

Click here to view and download the source code of Snake Game (23 KB).

Click here to view and download the images of Snake Game (8 KB).