java编写界面设置 背景图片的大小

ImageIcon background = new ImageIcon("res\\index.jpg");

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();//得到电脑屏幕的大小

Image temp = background.getImage().getScaledInstance((int)screenSize.getWidth(),
(int)screenSize.getHeight(), background.getImage().SCALE_DEFAULT);//设置图片大小跟屏幕大小一致
background = new ImageIcon(temp);//背景图片等于设置好后大小的图片

JLabel label = new JLabel(background);

label.setBounds(0, 0, (int)screenSize.getWidth(), (int)screenSize.getHeight());