The component which motioned with KeyListener moves only to middle

package learning;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

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

public class TestKeyListener extends JPanel implements KeyListener {

	int x = 1, y = 1, velX = 0, velY = 1;

	public TestKeyListener() {
		addKeyListener(this);
		setFocusable(true);
		setFocusTraversalKeysEnabled(false);
	}

	public static void main(String[] args) {
		TestKeyListener board = new TestKeyListener();
		JFrame frame = new JFrame();
		frame.setTitle("Field");
		frame.setSize(500, 500);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.add(board);
	}

	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		
		g.setColor(Color.GREEN);
		g.fillOval(x, y, 50, 50);
	}

	@Override
	public void keyPressed(KeyEvent arg0) {
		System.out.println("right");
		setX(getX() + 10);
		repaint();
	}

	@Override
	public void keyReleased(KeyEvent arg0) {
		// TODO Auto-generated method stub

	}

	@Override
	public void keyTyped(KeyEvent arg0) {
		// TODO Auto-generated method stub

	}

	public int getX() {
		return x;
	}

	public void setX(int x) {
		this.x = x;
	}

	public int getY() {
		return y;
	}

	public void setY(int y) {
		this.y = y;
	}

}