在java中怎么样设置JPanel里面的背景图片?

java要加背景图比较麻烦,需要重载paintComponent方法,下面以JPanel为例,其它按此继承就可 JPanel jContentPane = new getpane(800,600,"images\\0044.jpg"); jContentPane.setLayout(null); jContentPane.setOpaque(false);//此处要设为false jContentPane.setAlignmentY(0.5F); jContentPane.add(jLabel, null); jContentPane.add(getJTestYear(), null); this.initComboBox(); jContentPane.add(getJSearchByName(), null); jContentPane.add(getJSearchByID(), null); jContentPane.add(getJIDOrName(), null); jContentPane.add(jLabel1, null); jContentPane.add(getJPanel(), null); this.setContentPane(jContentPane); class getpane extends JPanel{ private static final long serialVersionUID = 1L; int width=0,hight=0; String imgpath = ""; public getpane(int width,int hight,String file){ this.width = width; this.hight = hight; imgpath = file;}protected void paintComponent(Graphics g) {