Ground problem

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
public class Player extends Actor
{
    private int ySpeed;
    private int apexTimer;
    public int iN = 1;
    public int count;
    public Player()
    {
    }
 
    public void act()
    {
        int groundLevel = getWorld().getHeight() - getImage().getHeight()/2;
        boolean onGround = (getY() == groundLevel);
        Movement();
        Aump();
        Dump();
        if (!onGround)
        {
            if (ySpeed == 0 && apexTimer > 0) apexTimer--; 
            if (ySpeed == 0 && apexTimer > 0) return;
            ySpeed++;
            setLocation(getX(), getY()+ySpeed);
            if (getY()>=groundLevel)
            {
                setLocation(getX(), groundLevel); 
                Greenfoot.getKey();
           }
        }
        else 
        {
            if ("w".equals(Greenfoot.getKey())) 
            {
                ySpeed = -15;
                setLocation(getX(), getY()+ySpeed);
                apexTimer = 5;
            }
        }
    }
    public void Movement()
    {
        if (Greenfoot.isKeyDown("S"))
        {
            setLocation(getX() , getY() + 3);
        }
        if (Greenfoot.isKeyDown("A"))
        {
            setLocation(getX() - 3, getY());
            _Animation();
        }
        if (Greenfoot.isKeyDown("D"))
        {
            setLocation(getX() +  3, getY() );
            Animation();
        }
    }
    public void Animation()
    {
        if(count % 3 == 0)

            iN++;
        if(iN == 8)
        {
            iN = 1;
        }
        setImage("W" + iN + ".png");
        count++;
        
    }
    public void _Animation()
    {
        if(count % 3 == 0)

            iN++;
        if(iN == 8)
        {
            iN = 1;
        }
        setImage("-W" + iN + ".png");
        count++;
    }
    public void Dump()
    {
        if(Greenfoot.isKeyDown("W"))
        {
            if(Greenfoot.isKeyDown("D"))
            {
                setImage("J1.png");
            }
        }
    }
    public void Aump()
    {
        if(Greenfoot.isKeyDown("W"))
        {
            if(Greenfoot.isKeyDown("A"))
            {
                setImage("-J1.png");
            }
        }
    }
}