Please tell me whether you think my code is useful.

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class MainMIDlet extends MIDlet implements Runnable
{
	Display display;
	MainCanvas mainCanvas;
	Thread thread;
	
	public MainMIDlet()
	{

		display = Display.getDisplay(this);
		mainCanvas = new MainCanvas(this);
		thread = new Thread(this);
	}
	public void startApp()
	{
		try{
		display.setCurrent(mainCanvas);
		thread.start();
		}catch(Exception e) {e.printStackTrace();}
		
	}
	public void run()
	{
		 mainCanvas.DBricks();
			while(!mainCanvas.gameover)
			{
		 	 if(!mainCanvas.pause)
		 	 {
					 if(mainCanvas.startgame)
					 {
						 mainCanvas.gameCode();
						 mainCanvas.BrickBreak();
						 mainCanvas.repaint();

					  try{
						  Thread.sleep(mainCanvas.speed);//increase the speed of the ball by reducing the value.
						  }
					  catch(Exception e){}
					 }
					 else
					 {
						 mainCanvas.BallX=mainCanvas.BatX+25;mainCanvas.BallY=mainCanvas.BatY-mainCanvas.bsize;
						 mainCanvas.repaint();
					 try{Thread.sleep(mainCanvas.speed+mainCanvas.temp);}catch(Exception e){}
					 }
		     }
		     else
		     {
		    	 mainCanvas.repaint();
				 try{Thread.sleep(mainCanvas.speed+mainCanvas.temp);}catch(Exception e){}
			 }
		   }
		while(true){
		try{
			Thread.sleep(150L);
			//System.out.println("Continuous running");
			mainCanvas.repaint();
		}catch(Exception e) {}
		}
	}
	public void pauseApp()
	{
		
	}
	public void destroyApp(boolean uc)
	{
		notifyDestroyed();
	}
	public void exitApp()
	{
		destroyApp(false);
	}
	
}
//






import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.LayerManager;
import javax.microedition.lcdui.game.Sprite;
//import java.util.Vector;

import java.util.Random;


public class MainCanvas extends Canvas
{
	/**
	 * MIDlet
	 */
	MainMIDlet midlet;


	/**
	 * determines which key is being pressed
	 */
	int keyPress = 0;

	
	//
	  //array to store the brick x,y and present bits of the brick.
	public static int Bricks[][];
	// varible for to chech the movement of the ball direction.
	public static boolean BdirectionY=true;
	public static boolean BdirectionX=true;
	//variable to check gameover or not.
	public static boolean gameover=false,startgame=false,pause=false;
	//varibales for brick width and height.
    public static int BWidth=30;
	public static int BHeight=15;

	//variable to specify the number of the bricks..
	public static int size=23;
    public int screenWidth=getWidth();
    public int screenHeight=getHeight();
	public static int BatX=120,BatY=280;
	public static int BatW=50;
	public static int bsize=10,life=3,score=0,win=0;
	public static int temp=20;
	public static int BallX=BatX+25,BallY=BatY-bsize;
	public static int s=-5;
	public static int speed=50;
	int index=0;
	private Image bomb;
	private boolean bbool =false;
	private int Bheight=140;
	
	/**
	 * constructor having the MIDlet as the parameter
	 */
	public MainCanvas(MainMIDlet midlet)
	{
		this.midlet = midlet;
		setFullScreenMode(true);
		Bricks=new int [size][5];
		try{
		bomb = Image.createImage("/Bomb.png");      
		}catch (Exception e) {
			// TODO: handle exception
		}
	
	}

	/**
	 * paint Method which is an abstract method in Canvas 
	 */
	public void paint(Graphics g)//
	{
		g.setColor(255,0,255);
		g.fillRect(0,0,getWidth(),getHeight());
		Ballmove(g);
		
		if(bbool){
			Bheight+=4;
			g.drawImage(bomb, 70, Bheight, Graphics.TOP | Graphics.LEFT);
		}
	}
	
	    void BrickBreak()
		{

	  // code for ball hitting bat.
		   if((BallX<=BatX+BatW&&BallX>=BatX&&BallY+bsize==BatY)||(BallX+bsize<=BatX+BatW&&BallX+bsize>=BatX&&BallY+bsize==BatY))
				{
			   
			      BdirectionY=true;
			      
				}

		  for(int i=0;i<size;i++)
		  {
			 //code for ball hitting the brick from bottom
			 if(BallX>=Bricks[i][0]&&BallX<=Bricks[i][0]+BWidth&&BallY==Bricks[i][1]+BHeight)
			 {

				  Bricks[i][0]=s;
				  Bricks[i][1]=s;
				  Bricks[i][2]=0;
				  Bricks[i][4]=0;
				  Bricks[i][3]=0;
				  if((Bricks[1][3]==0)&& bbool==false)
					 {
					  System.out.println("bomb");
					  bbool = true;
					 }
				  BdirectionY=false;
				  score+=10;
				  win+=1;

			 }

			 //code for ball hitting the brick from top
			 else if(BallX>=Bricks[i][0]&&BallX<=Bricks[i][0]+BWidth&&BallY+bsize==Bricks[i][1])
			 {
				 Bricks[i][0]=s;
				 			  Bricks[i][1]=s;
				 			  Bricks[i][2]=0;
				 			  Bricks[i][4]=0;
				 			  Bricks[i][3]=0;
				  BdirectionY=true;
				  score+=10;
				  win+=1;
			 }
			 //code for ball hitting the brick from left side.
	        else if((BallX+bsize==Bricks[i][0]&&BallY>=Bricks[i][1]&&BallY<=Bricks[i][1]+BHeight))
	        {
				Bricks[i][0]=s;
				Bricks[i][1]=s;
				Bricks[i][2]=0;
				Bricks[i][4]=0;
				Bricks[i][3]=0;
				BdirectionX=true;
				score+=10;
				win+=1;
			}
			//code for ballhitting the brick from right side
			else if((BallX==Bricks[i][0]+BWidth&&BallY>=Bricks[i][1]&&BallY<=Bricks[i][1]+BHeight))
			{
				Bricks[i][0]=s;
							Bricks[i][1]=s;
							Bricks[i][2]=0;
							Bricks[i][4]=0;
							Bricks[i][3]=0;
				BdirectionX=false;
				score+=10;
				win+=1;
			}

			}


			if(win==size)
			{
				index =4;
			}

		}



		void gameCode()
		{
			//code checking whether ball moving up or down
			if(BdirectionY)
			{
				BallY-=5;
				
	          if(BallY<(temp+5))		//up
			 {
	        	  System.out.println("up collision");
	        	 
	          BdirectionY=false;
			  }
			}
			else
			{
				if(Bheight>(screenHeight-50)&& bbool==true){
					System.out.println("bomb collision");
					bbool =false;
				}
	        
				BallY+=5;
	           if(BallY>(screenHeight-((temp/3)-12)))
			   {
	        	System.out.println("down collision");
	            BallY=BatY;
				BallX=BatX+35;
				  
				BdirectionY=true;
				startgame=false;
				life-=1;
				if(life==0)
				{
	
					index=2;
			    }
			    }
			}
	//code checking whether ball moving right ro left.
			if(BdirectionX)
			{

			  BallX-=5;
	          if(BallX<10)
			 {
	          BdirectionX=false;
			  }
			}
			else
			{

				BallX+=5;
	           if(BallX>(screenWidth-((temp/2)+10)))
			   {
	            BdirectionX=true;
			   }
			}

		}
	    void DBricks()
		{
			//System.out.println("Brick ");
		 int x=25;
		 int y=60;
			//setting the brick positons.
		 for(int i=0;i<size;i++)
	     {
				if(i==2)
				      {
						y=20;
						x=10;
					   }
				
				/*if(i==13)
			      {
					y-=temp;
					x=(BWidth*2);
				   }
				if(i==temp)
					{
				    y=180;
					x=80;
					}*/
				
//				if(i==12)
//			      {
//					y-=temp;
//					x=(BWidth*2);
//				   }
//				if(i==15)
//				   {
//					x=25+BWidth;
//					y=160;
//					}
//				if(i==temp)
//					{
//				    y=180;
//					x=80;
//					}

			    Bricks[i][0]=x;
				Bricks[i][1]=y;
				Bricks[i][2]=1;
				Bricks[i][3]=BWidth;
				Bricks[i][4]=BHeight;
				x+=BWidth;
			   
		}
/*
	//setting the brick positons.
		for(int i=0;i<size;i++)
	     {
				 if(i==7)
	     			{
					 y-=temp;
					 x=25+BWidth;
		     		}
				if(i==12)
			      {
					y-=temp;
					x=25+(BWidth*2);
				   }
				if(i==15)
				   {
					x=25+BWidth;
					y=160;
					}
				if(i==temp)
					{
				    y=180;
					x=80;
					}

		    Bricks[i][0]=x;
			Bricks[i][1]=y;
			Bricks[i][2]=1;
			Bricks[i][3]=BWidth;
			Bricks[i][4]=BHeight;
			x+=BWidth;
		   }*/
		}
void DrawBall(Graphics g)
{
	g.setColor(255,0,0);
	g.fillArc(BallX,BallY,bsize,bsize,0,360);
	
}
 void DBat(Graphics g)
   {
     g.setColor(0,0,255);
	 g.fillRect(BatX,BatY,BatW,10);
	
	}
	//bat movements towards right.
	void Rkeymove()
		{
			if(BatX<(getWidth()-((temp*3)+bsize)))
				BatX+=15;
		}
		//bat movements towards left.
	void Lkeymove()
		{
				if(BatX>(bsize)+5)
				BatX-=15;
		}
	void DrawBricks(Graphics g)
	{
		for(int i=0;i<size;i++)
	    {
        	if(Bricks[i][2]==1)
	        {
			  g.setColor(0,0,0);
			  g.fillRect(Bricks[i][0],Bricks[i][1],Bricks[i][3]-2,Bricks[i][4]-2);
			 }
          }
     }
	void gameOver(Graphics g)
	{
		// g.setColor(Color.red);
		 // g.fillRect(0,0,ScreenWidth,ScreenHeight);
	  g.setColor(0,0,255);
	  g.drawString("YOU LOSE",(screenWidth/3),screenHeight/2,Graphics.TOP | Graphics.HCENTER);
	}
	
	public void Ballmove(Graphics g)
	{
		
		
		DrawBall(g);
		DBat(g);
		DrawBricks(g);
		g.drawRect((temp/7),20,screenWidth-((temp/2)-5),screenHeight-((temp/3)));
		g.setColor(0x000000);
		g.setStrokeStyle(Graphics.SOLID);
		g.drawString("LIFE : "+life,screenWidth-10,3, (Graphics.TOP | Graphics.RIGHT));
		g.drawString("SCORE: "+score,screenWidth/2+(temp),3,Graphics.TOP | Graphics.HCENTER);
		g.drawString("press '8' to Pause",5,3,(Graphics.TOP | Graphics.LEFT));
		
		switch (index) {
		case 1:			// pause
			pauseGame(g);
			break;
		case 2:		// gameover
			 gameOver(g);
			 index = 2;
			break;
		case 3:			// palyAgian
			 playAgain(g);
			break;
		case 4:
			gameWin(g);
			break;
			
		}
		keyEvents();

	}
	//method to disply win screen
	void gameWin(Graphics g)
	{

	 g.setColor(0,0,255);
	 g.fillRect(0,0,screenWidth,screenHeight);
	 g.setColor(255,0,0);
	 g.drawString("YOU WIN",(screenWidth>>2),screenHeight>>2,Graphics.TOP | Graphics.HCENTER);

	}
	void pauseGame(Graphics g)
	{
	  g.setColor(255,255,255);
	  g.fillRect(0,0,screenWidth,screenHeight);
		
	  g.setColor(255,0,0);
	  g.setStrokeStyle(Graphics.SOLID);
	  g.drawString("GamePaused Press '8' to Resume", 40, screenHeight>>1, Graphics.TOP | Graphics.LEFT);
//	  g.drawString("GamePaused Press 'P' to Resume",(temp+3),ScreenHeight/2);
	}
	//method to display play again screen.
	void playAgain(Graphics g)
	{
	//	g.setColor(Color.pink);
	//		   g.fillRect(0,0,ScreenWidth,ScreenHeight);
			   g.setColor(255,0,0);
       g.drawString("Press S PalyAgain",(screenWidth>>1),screenHeight>>1,(Graphics.TOP | Graphics.HCENTER));
}
	/**
	 * Gives the key being pressed. call-back method in Canvas
	 */
	public void keyPressed(int key)
	{
	
		switch(key)
		{
		case 48:
//			reverse = !reverse;
			break;
		case -1:
				keyPress |= 1;
				startgame = true;
			break;
		case -2:
				keyPress |= 2;
				 pause=!pause;
			       if(pause)
			    	  index=1;
                 else
                	 index=0;
			break;
		case -3:
				keyPress |= 4;
				
			break;
		case -4:
				keyPress |= 8;
				
			break;
		case 52:
			 if(index==3)
			 {
			   life=3;
			   score=0;
			   DBricks();
			   index=0;
		    }
		}
		
	}
	public void keyRepeated(int key)
	{
		switch(key)
		{
		case -1:
			
			
			break;
		case -2:
			
			break;
		case -3:
			System.out.println("1111111111");
			Lkeymove();
			break;
		case -4:
			
			Rkeymove();
			break;
		}
		
	}
	/**
	 * Gives the key being Released. call-back method in Canvas
	 */
	public void keyReleased(int key)
	{
//		System.out.println(key);
		switch(key)
		{
		case -1:
			keyPress ^= 1;
			
			break;
		case -2:
			keyPress ^= 2;
			
			break;
		case -3:
			keyPress ^= 4;
			
			break;
		case -4:
			keyPress ^= 8;
			break;
		}
	}

	
	/**
	 * controls the snake movements.
	 */
	public void keyEvents()
	{
		
	}
}