SWING设置背景图片

import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.filechooser.FileNameExtensionFilter;

public class DrawBackgroundImage extends JFrame {
	private JLabel bgL = new JLabel();

	public DrawBackgroundImage() {
		setTitle("设置背景图片");
		setSize(500, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLocationRelativeTo(null);

		JPanel p = new JPanel() {
			private static final long serialVersionUID = 1L;

			@Override
			protected void paintComponent(Graphics g) {
				if (bgL.getIcon() != null) {
					g.drawImage(((ImageIcon)bgL.getIcon()).getImage(), 0, 0, null);
				}
			}

		};

		JButton btn = new JButton("选择背景图片");
		btn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				JFileChooser jfc = new JFileChooser();
				FileNameExtensionFilter imageExtension = new FileNameExtensionFilter("Image Files (.jpg | .jpeg | .bmp | .png | .gif)", "jpg","jpeg","bmp","png","gif");
				jfc.addChoosableFileFilter(imageExtension);
				jfc.setDialogType(JFileChooser.SAVE_DIALOG);
				int res = jfc.showSaveDialog(DrawBackgroundImage.this);
				
				if (res == JFileChooser.APPROVE_OPTION) {
					File file = jfc.getSelectedFile();
					System.out.println(file.getAbsolutePath());
					setBg(new ImageIcon(file.getAbsolutePath()));
				}
			}
		});
		p.add(btn);
		this.getContentPane().add(p);
		
		// 添加一些组件，便于查看
		String[][] rowData = new String[9][2];
		for (int i=0;i<9;i++) {
			rowData[i][0] = "值1";
			rowData[i][1] = "值2";
		}
		String[] columnNames = {"列1","列2"};
		JTable table =new JTable(rowData, columnNames);
		p.add(new JScrollPane(table));
	}
	
	public void setBg(ImageIcon icon) {
		bgL.setIcon(icon);
		repaint();
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		new DrawBackgroundImage().setVisible(true);

	}

}