public void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D)g ; 
        Paint oldPaint = g2.getPaint() ; 
        if(isEntered){
        if (getModel().isArmed()) {
            g2.setColor(bacClick);
            
        } else
            g2.setColor(bacNormal);

        
        GradientPaint p = new GradientPaint(0,0,
                new Color(0xFFFFFF), 0, 2, bacNormal);
        g2.setPaint(p) ; 
        g2.fillRoundRect(0, 0, getWidth()- 1, getHeight() /2+10, 5, 5);
        GradientPaint pInigel = new GradientPaint(0,getHeight()/2-10,bacNormal,0,getHeight(),new Color(0xFFFFFF)) ; 
        g2.setPaint(pInigel) ; 
        g2.fillRoundRect(0, getHeight()/2-5, getWidth()- 1, getHeight(), 5, 5);
        }
        g2.setFont(new Font("方正舒体", 0, 30));
        if (getModel().isArmed()) {
            g2.setColor(bacNormal);

        } else
            if(isEntered)
                g2.setColor(Color.YELLOW) ; 
            else
            g2.setColor(foreGround);

        g2.drawString(text,1, getHeight()/ 2 + 9);
        g2.setPaint(oldPaint) ; 
        super.paintComponent(g);
    }

package xsb.weiwei;
import javax.swing.* ; 

import java.awt.* ; 
import java.awt.event.* ; 
import java.awt.geom.RoundRectangle2D;


public class XJButton extends JButton implements MouseListener {
    private String text;
    private Color bacNormal;
    private Color foreGround;
    private Color bacClick;
    private Shape shape = null;
    private int height ; 
    private boolean isEntered ;

    public XJButton(String text) {
        this.text = text;
        bacNormal = new Color(0xFFB6C1);
        foreGround = new Color(0x000000);
        bacClick = Color.GRAY;
        setContentAreaFilled(false);
        addMouseListener(this);
        isEntered = false ; 
        height = 45 ; 
        
        
    }

    public void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D)g ; 
        Paint oldPaint = g2.getPaint() ; 
        if(isEntered){
        if (getModel().isArmed()) {
            g2.setColor(bacClick);
            
        } else
            g2.setColor(bacNormal);

        
        GradientPaint p = new GradientPaint(0,0,
                new Color(0xFFFFFF), 0, 2, bacNormal);
        g2.setPaint(p) ; 
        g2.fillRoundRect(0, 0, getWidth()- 1, getHeight() /2+10, 5, 5);
        GradientPaint pInigel = new GradientPaint(0,getHeight()/2-10,bacNormal,0,getHeight(),new Color(0xFFFFFF)) ; 
        g2.setPaint(pInigel) ; 
        g2.fillRoundRect(0, getHeight()/2-5, getWidth()- 1, getHeight(), 5, 5);
        }
        g2.setFont(new Font("方正舒体", 0, 30));
        if (getModel().isArmed()) {
            g2.setColor(bacNormal);

        } else
            if(isEntered)
                g2.setColor(Color.YELLOW) ; 
            else
            g2.setColor(foreGround);

        g2.drawString(text,1, getHeight()/ 2 + 9);
        g2.setPaint(oldPaint) ; 
        super.paintComponent(g);
    }

    public void paintBorder(Graphics g) {
        if(isEntered){
        g.setColor(Color.BLACK);
        g.drawRoundRect(0, 0, getWidth()-1,getHeight()-1, 20, 20);
        }
    }

    public boolean contains(int x, int y) {
        if (shape == null || shape.getBounds().equals(getBounds())) {
            shape = new RoundRectangle2D.Float(0, 0, getWidth(), getHeight(),
                    20, 20);

        }
        return shape.contains(x, y);
    }

    @Override
    public void mouseClicked(MouseEvent arg0) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseEntered(MouseEvent arg0) {
        // TODO Auto-generated method stub
        isEntered = true ; 
        setCursor(new Cursor(Cursor.HAND_CURSOR)) ; 
        repaint() ; 
        
    }

    @Override
    public void mouseExited(MouseEvent arg0) {
        // TODO Auto-generated method stub
        isEntered = false ; 
        repaint() ; 
    }

    @Override
    public void mousePressed(MouseEvent arg0) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseReleased(MouseEvent arg0) {
        // TODO Auto-generated method stub
        
    }
    public int getWidth(){
        return text.length()*35 ; 
    }
    public int getHeight(){
        return height ; 
    }
    public String getString(){
        return text; 
    }
    public static void main(String[] args){
        JFrame jfm = new JFrame("") ;
        jfm.setSize(200,200) ; 
        jfm.setLocation(new Point(400,400)) ;
        XJButton x = new XJButton("尝试") ;
        x.setOpaque(false) ;
        jfm.getContentPane().add(x) ; 
        
        jfm.setVisible(true) ; 
        jfm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ; 
    }

}