Thread: collision between player and platform

my main goal to:
make player jump on platform.

(goal-1).if player jump on platform than player should stand on platform.

(goal-2).if player is below the platform than he jump. and if his head hits the platform than player should not go though it. it should bonce back down.

(goal-3). if player walk right or left of platform than player should stop.

some variabble information:

x = platform x postion
y = platform y postion
width = platform width
height = platform width 
playerX = player x postion
playerY = player y postion
playerW = player width
playerH = player height
p.setY() = set player y postion

this code below create a collision around platform.

if(playerX + playerW >= x && playerX <= x + width)
 {
      if(playerY+playerH >= y && playerY <= y+height)
      {
      }
}

(goal-1) done below
now if player jump on platform than iam setting setting player y postion so that player is on platform.

if(playerX + playerW >= x && playerX <= x + width)
		{
		    if(playerY+playerH >= y && playerY <= y+height)
		    {
	p.setJUMP(false);
				p.setY(y - playerH); 
}
}

now i need help with goal-2,3:




platform.java

public class Platform 
{
	private int dx;     //plat form speed
	private int x;      //x postion
	private int y;      //y postion
	private int width;  //width 
	private int height;  //height
 
	Image platform_image;
	float frame = 0; //start from 0 frame-total 3 frame-012
 
 
 
 
	public Platform(int x, int y)
	{
		this.x = x;
		this.y = y;
		width = 120;
		height = 40;
		dx = 1;
		platform_image = Sprite_Sheet.platform_sheet;
	}
 
 
 
	/*** for player collsion - name stay same ***/
	public Rectangle getBounds()
	{ return  new Rectangle(x, y, width,height);}
 
 
	public int getWIDTH()
	{
		return width;
	}
 
 
 
	public void PLATFORM_ANIMATION()
	{
		int tester = (int)(frame + .1); //.1 slow down
		if(tester < 3)
		{
			frame += .1;
		}
		else
		{
			frame = 0;
		}
	}
 
 
	//update method
	public void PLATFORM_COLLSION(Main m, Player p)
	{	
 
		x -= dx;  //move platform left
 
		//loop back same platform left to right
		if(x < 0 - width) 
		{
			Random r = new Random();
			x = m.getWidth() + r.nextInt(300);
			y = m.getHeight() - r.nextInt(400);
		}
		checkForCollision(p); //in update bc this is in loop
	}/*** end of platform_collsion ***/
 
 
 
 
 
 
	private void checkForCollision(Player p) //we control Player class
	{
		int playerX = p.getX();
		int playerY = p.getY();
		int playerW = p.getWIDTH();
		int playerH = p.getHEIGHT();
 
		/* not a good idea but works fine
		if(p.getBounds().intersects(this.getBounds()))
		{
			//we selected only the platform
				p.setJUMP(false);
				p.setY(y - playerH+9); //stay on platform height
		}*/
 
		if(playerX + playerW >= x && playerX <= x + width)
		{
		    if(playerY+playerH >= y && playerY <= y+height)
		    {
		    	p.setJUMP(false);
				p.setY(y - playerH); 
		    }
		}
	}
 
 
 
 
	//draw ground
	public void paint(Graphics g)
	{
		//g.drawImage(img, dx1, dy1, dx2, dy2, sx1, sy1, sx2, sy2, observer)
		//dx1 = x postion top left conver
		//dy1 = y postion top left coner
		//dx2 = x postion bottom right conver
		//dy2 = y postion bottom right coner
		//sx1 = x cut off postion top left coner
		//sx1 = x cutt of postion top left coner
		//sx2 = x cut off postion bottom right coner
		//sy2 = y cut off postion bottom right coner
			//to display 1st frame
			//g.drawImage(platform_image, x, y, x+width, y+height,0, 0, width, height,Sprite_Sheet.m1);
		//loop 3 frames
		g.drawImage(platform_image,x, y, x+width, y+height, 0, height*(int)frame, width, height*(int)frame+height,Sprite_Sheet.m1);
 
	}
}

player.java

public class Player 
{
	//Player movement variable
	private int sx = 10;
	private int sy = 200;
	private int x;     //current x
	private int y;     //current y
	private int width = 30;
	private int height = 40;
	private int dx = 2;    //speed of player
 
	private double dy = 6.0;  //change in y over time
	private double gravity = 0.2;    
 
 
	private boolean dead = false;
 
	private boolean look_right = true;
	private boolean walk_right;
	private boolean walk_left;
	private boolean jump = false;
	private boolean fall = false;   //fall without jump. so hold right on platform. it will fall               
	private boolean hitSPACE = false;
 
 
	/*** image variable ***/
	Image player_image;
	URL url;
	float frame = 0; 
 
 
	/*** constructor Method ***/
	public Player()
	{
	}
	/*** constructor Method2 ***/
	public Player(int ix, int iy) 
	{
		x = ix;
		y = iy;
		player_image = Sprite_Sheet.player_sheet;
	}	
 
 
		/*** for player collsion - name stay same ***/
		public Rectangle getBounds()
		{ return  new Rectangle(x, y, 13,30);}
 
 
		public boolean isDEAD()
		{ return dead; }
		public void setDEAD(boolean value) 
		{ this.dead =  value; }
 
		public int getX()
		{ return x; }
		public void setX(int value) 
		{ this.x =  value; }
 
		public int getY()
		{ return y; }
		public void setY(int value) 
		{ this.y =  value; }
 
		public int getDX()
		{ return dx; }
		public void setDX(int value) 
		{ this.dx =  value; }
 
		public int getWIDTH()
		{ return width; }
		public void setWIDTH(int value) 
		{ this.width =  value; }
 
		public int getHEIGHT()
		{ return height; }
		public void setHEIGHT(int value) 
		{ this.height =  value; }
 
		public double getGRAVITY()
		{ return gravity; }
	    public void setGRAVITY(double value) 
		{ this.gravity =  value; }
 
		public double getDY()
		{ return dy; }
	    public void setDY(double value) 
		{ this.dy =  value; }
 
	    public void setJUMP(boolean value)
	    { this.jump = value; }
 
	    public void setFALL(boolean value)
	    { this.fall = value; }
 
 
 
 
 
 
		/*** main key methods ***/
		/*** RIGHT ***/
		public void hitRIGHT()  //if user hit right button
		{ 
			walk_right = true; 
			look_right = true;
		}
		public void stopRIGHT() //if user let go of right button
		{
			walk_right = false;  //stop 
			look_right = true;
		}
 
		/*** LEFT ***/
		public void hitLEFT()  //move left
		{
			walk_left = true;
			look_right = false;
		}
		public void stopLEFT()
		{
			walk_left = false;  //stop
			look_right = false;
		}
 
		/*** JUMP ***/
		public void hitJUMP(Ground g)
		{
			if(jump == false)//if on ground 
			{
				jump = true;
				dy = 6.0;	//reset
			} 
		}
 
 
 
 
 
		/**************************/
		/****** LOOP METHODS ******/
		/**************************/
		/*** player move method ***/
		public void PLAYER_MOVE(Main m, Ground g) //player move's
		{
			int tester = (int)(frame + .1); //.1 slow down
			if(tester < 3)
			{
				frame += .1;
			}
			else
			{
				frame = 0;
			}
 
 
			if(walk_right == true)
			{
					x += dx;
			}
			else if(walk_right == false)
			{
			}
 
			if(walk_left == true)  //walking left
			{
				if(x - dx < 0)  //cant go left
				{
					x = 0;
				}
				else
				{
					x -= dx;      //move left
				}
			}
			else if(walk_left == false)
			{
			}
 
			if(jump == true) 
			{	
				dy -= gravity;
				y -= dy;
 
				if(y+height >= g.getY()) //if on ground
				{
					jump = false;
				}
			}
			else if(jump == false) //move player down when game starts
			{
				y += 2; //fall of platform speed or start of game going down
				fall = true;
			}
		}/***end of update method ***/
 
 
 
 
 
 
 
 
 
 
		/*** paint method ***/
		public void paint(Graphics g)
		{
			if(jump == false)
			{
				if(look_right == true)
					{
						if(dead == false && walk_right == true) //walk right
						{	
							g.drawImage(player_image, x, y, x+width, y+height, 
									40*(int)frame, 47, 40*(int)frame+40, 90 ,Sprite_Sheet.m1);
 
						}
						else if(dead == false && walk_right == false) //stand right
						{
 
							g.drawImage(player_image, x, y, x+width, y+height, 
									0, 0, 40 , 42,Sprite_Sheet.m1);
						}
						else if(dead == true)
						{
							g.drawImage(player_image, x, y+10, x+width, y+height, 
									0, 230, 40, 268 ,Sprite_Sheet.m1);
						}
					}
				else if(look_right == false)
				{
					if(dead == false && walk_left == true) //walk left
						{
						g.drawImage(player_image, x, y, x+width, y+height, 
								40*(int)frame, 87, 40*(int)frame+40, 125 ,Sprite_Sheet.m1);
						}
					else if(dead == false && walk_left == false) //stand left
					{
						g.drawImage(player_image, x, y, x+width, y+height, 
								40, 0, 80, 42 ,Sprite_Sheet.m1);
					}
					else if(dead == true)
					{
						g.drawImage(player_image, x, y+10, x+width, y+height, 
								41, 230, 82, 268 ,Sprite_Sheet.m1);
					}
				}	
			}
			else if(jump == true)
			{
				if (dead == false && look_right == true) //jump right
				{
					g.drawImage(player_image, x, y, x+width, y+height, 
							0, 129, 40, 172 ,Sprite_Sheet.m1);
				}
				else if(dead == true && look_right == true)  //dead right
				{
					g.drawImage(player_image, x, y+10, x+width, y+height, 
							0, 230, 40, 268 ,Sprite_Sheet.m1);
				}
				else if(dead == false && look_right == false) //jump left
				{
					g.drawImage(player_image, x, y, x+width, y+height, 
							0, 187, 40, 236 ,Sprite_Sheet.m1);
				}
				else if(dead == true && look_right == false)
				{
					g.drawImage(player_image, x, y+10, x+width, y+height, 
							41, 230, 82, 268 ,Sprite_Sheet.m1);
				}
			}
		}
}/*** end of class ***/

main.java

public class Main extends Applet implements Runnable, KeyListener, MouseMotionListener, MouseListener
{
	//Double buffering variables
	Image dbImage;
	Graphics dbGraphics;
 
	Thread thread;
 
 
 
	//Class variables
	 Background background_class;
	 Score score_class;
	 Ground ground_class;
	 Sprite_Sheet sprite_sheet_class;
	 Player player_class;
	Platform platform_class[] = new Platform[5];
	Enemy  enemy_class;
	Item item_class[] = new Item[3];
	Shoot shoot_class;
 
 
	 //is if game is running or not
	 boolean running = true;
	 boolean mouseIn = false;
 
	 Container c;
 
 
 
 
	/*** init method ***/
	@Override
	public void init() 
	{
		setSize(900, 400);
		addKeyListener(this);
		addMouseListener(this);
		addMouseMotionListener(this);
 
	}/*** end of init method ***/
 
 
 
 
	/*** start method ***/
	@Override
	public void start()
	{	
		/*** set variables ***/
		Random r1 = new Random();
 
		ground_class = new Ground(0, this.getHeight()-20,this.getSize().width, 20); //x, y, widith, height
		sprite_sheet_class = new Sprite_Sheet(this);
		background_class = new Background();
		player_class = new Player(5, 250);  //x, y
		for(int i = 0; i < platform_class.length; i++)
		{ 
		  Random r = new Random();
		  platform_class[i] = new Platform(i*120, 300); //x,y --sub -40 so no cut off platform at bottom
		}
		//item_class = new Item_0_Background(200); //x print 1 item
		for(int i = 0; i < item_class.length; i++)
		{ item_class[i] = new Item_1_Fast(r1.nextInt(900)); } //x  - print 1 item than swich to 2nd item
		shoot_class = new Shoot();
		enemy_class = new Enemy(500, 345);   //x, y
 
		score_class = new Score(5,30);
 
 
		/*** play music in main ***/
		sprite_sheet_class.theme_music.loop();
 
 
 
		thread = new Thread(this); //start run method
		thread.start();
	}/*** end of start method ***/
 
 
 
	/*** run method ***/
 
	public void run()
	{
		while(player_class.isDEAD() == false) //if player is not dead keep going
		{
			background_class.BACKGROUND_MOVE(this);
 
			//set score
			score_class.SCORE();
			score_class.health(player_class, enemy_class, sprite_sheet_class);
 
			Random r = new Random();
			ground_class.GROUND_COLLISION(this, player_class);                         //ground + player collions
			player_class.PLAYER_MOVE(this, ground_class);                                  //player moves
 
			for(int i = 0; i < platform_class.length; i++)
			{ platform_class[i].PLATFORM_ANIMATION();
				platform_class[i].PLATFORM_COLLSION(this, player_class); }
			shoot_class.PLAYER_SHOOT_MOVE(this, player_class, shoot_class);  //player shoot bullet moves
			enemy_class.ENEMY_MOVE(this, sprite_sheet_class);
			enemy_class.PLAYER_ENEMY_COLLISION(this, player_class, enemy_class);          //player + enemy collision
			for(int i = 0; i < item_class.length; i++)
			{
			item_class[i].PLAYER_ITEM_COLLISION(this, score_class, player_class,  ground_class);
				if(item_class[i].getY() == 0)         //if item is top left coner
				{
					item_class[i] = null;                 //delete item
					item_class[i] = new Item_0_Background(r.nextInt(900)-50);
					int ra = r.nextInt(4);
					if(ra == 0)
					{
						item_class[i] = new Item_0_Background(r.nextInt(900)-10);  //create new item
					}
					else if(ra == 1)
					{
						item_class[i] = new Item_1_Fast(r.nextInt(900)-10);  //create new item
					}
					else if(ra == 2)
					{
						item_class[i] = new Item_2_SLOW(r.nextInt(900)-10); //	swich to different item
					}
					else if(ra == 3)
					{
						item_class[i] = new Item_3_Score(r.nextInt(900)-10);
					}
				}
			}
 
 
			/* msuic when player is dead */
			if(player_class.isDEAD() == true)
			{
				sprite_sheet_class.theme_music.stop();
				sprite_sheet_class.dead_music.play();
			}	
 
			repaint();
			try
			{
				Thread.sleep(10);
			}
			catch(InterruptedException e)
			{
				e.printStackTrace();
			}
		}
	}/*** end of run method ***/
 
 
 
 
 
 
 
	/*** update method ***/
	@Override
	public void update(Graphics g) 
	{
		if(dbImage == null) //if image is empty than create new image
		{
			dbImage = createImage(this.getSize().width, this.getSize().height);
			dbGraphics = dbImage.getGraphics();
		}
		dbGraphics.setColor(getBackground());  //set the background color
		dbGraphics.fillRect(0, 0, this.getSize().width, this.getSize().height);
		dbGraphics.setColor(getForeground());
		paint(dbGraphics);     //call paint method
		g.drawImage(dbImage, 0, 0, this);
	}/*** end of update method ***/
 
 
 
 
 
 
	/*** paint method ***/
	@Override
	public void paint(Graphics g) 
	{
		background_class.paint(g, this);
		ground_class.paint(g);             //call paint method from Ground class  //draw ground than player on top
 
		player_class.paint(g);             //call paint method from Player classr 
		for(int i = 0; i < platform_class.length; i++)
		{ platform_class[i].paint(g); }
		shoot_class.paint(g); //draw bullet
		if(enemy_class.isDEAD() == false)  //draw enemy if it's not dead
		{
			enemy_class.paint(g);
		}
		for(int i = 0; i < item_class.length; i++)
		{ item_class[i].paint(g); }
		score_class.paint(g, this, player_class);
 
	}/*** end of paint method ***/
 
 
 
 
 
 
	/*** stop method ***/
	@Override
	public void stop()
	{
 
	}/*** end of stop method ***/
 
	/*** destroy method ***/
	@Override
	public void destroy()
	{
	}/*** end of destroy method ***/
 
 
 
 
 
 
 
 
 
 
 
 
 
	/************** key *********************/
	@Override
	public void keyPressed(KeyEvent e)
	{
		int keys = e.getKeyCode();
		if(keys == KeyEvent.VK_RIGHT) 
		{
			player_class.hitRIGHT();
			sprite_sheet_class.running_music.loop();
		}
		else if(keys == KeyEvent.VK_LEFT)
		{
			player_class.hitLEFT();
			sprite_sheet_class.running_music.loop();
 
		}	
		else if (keys == KeyEvent.VK_UP)
		{
			player_class.hitJUMP(ground_class);
			sprite_sheet_class.jump_music.play();
 
		}
		else if(keys == KeyEvent.VK_SPACE)
		{
			shoot_class.hitSHOOT();
		}
	}
	@Override
	public void keyReleased(KeyEvent e)
	{
		int keys = e.getKeyCode();
		if(keys == KeyEvent.VK_RIGHT) 
		{
			player_class.stopRIGHT();
			sprite_sheet_class.running_music.stop(); 
		}
		else if(keys == KeyEvent.VK_LEFT)
		{
			player_class.stopLEFT();
			sprite_sheet_class.running_music.stop(); 
		}	
		else if(keys == KeyEvent.VK_SPACE)
		{
			shoot_class.stopSHOOT();
		}
 
	}
	@Override
	public void keyTyped(KeyEvent e){}
 
 
 
 
 
 
 
 
/*** mouse mostion ***/
	@Override
	public void mouseDragged(MouseEvent e) {}
	@Override
	public void mouseMoved(MouseEvent e) 
	{
			if(e.getX() > 270 && e.getX() < 460)
			{
				if(e.getY() > 310 && e.getY() < 350)
				{
					mouseIn = true;
				}
			}
 
 
			if(e.getX() < 280 || e.getX() > 460)
			{
					mouseIn = false;
 
			}
			if(e.getY() < 320 || e.getY() > 360)
			{
				mouseIn = false;
			}
	}
 
 
 
 
 
 
 
 
 
	/************    MOUSE  **********/
	@Override
	public void mousePressed(MouseEvent e)
	{
		//start game over
		if(mouseIn == true)
		{
			start();
		}
		//mouseIn = false;
	}
	public void mouseReleased(MouseEvent e){}
	public void mouseClicked(MouseEvent e){}
	public void mouseEntered(MouseEvent e){}
	public void mouseExited(MouseEvent e){}
 
 
 
 
}

no i didnt started it. i need help with logic first.

here is what iam thinking, my main code should be in these if statment

if (playerX <= x && playerY+playerH >= y) //player on right of platform and player feet is lower than platform
{
System.out.println("right");
p.setX(x - playerW);
}
else if(playerX >= x && playerY+playerH >= y) //player on left of platform
{
System.out.println("left");
p.setX(x + width);
}
else if(playerY+playerH <= y) //player on top of platform
{
System.out.println("top");
p.setJUMP(false);
p.setY(y - playerH);
}

but now the player on top if statment dont work. but player right and player left if statment works fine.