swing 替换标题图片与插入背景图片

1.替换标题图片

    Image img=Toolkit.getDefaultToolkit().getImage("img/2.jpg"); //用以接收图片的URL    setIconImage(img);//获得图片

2.Jpanel插入背景图片

import java.awt.Graphics;import java.awt.Image;import javax.swing.JPanel;public class BackgroundPanel extends JPanel{    /**     *      */    private static final long serialVersionUID = 916877989182209631L;    private Image image=null;    public BackgroundPanel(Image image)    {        this.image=image;    }     protected void paintComponent(Graphics g) {              g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), this);  // 固定背景图片，允许这个JPanel可以在图片上添加其他组件         }  }//Image image=new ImageIcon("img/1.jpg").getImage(); //插入图片        JPanel jPanel1=new BackgroundPanel(image);//将图片写入jpanel1