swing之UI选择文件

package gui1;import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.filechooser.FileNameExtensionFilter;/**
*
* @author luozt
*/
public class TestFrame extends JFrame{
static JTextField TextField;
static TestFrame testFrame; public static void main(String args[]){
testFrame=new TestFrame();
TextField=new JTextField(" ");
JButton button=new JButton("选择文件");
button.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
//--核心代码
JFileChooser chooser = new JFileChooser("./");
FileNameExtensionFilter filter = new FileNameExtensionFilter(
"文本文档", "txt");
chooser.setFileFilter(filter);
int returnVal = chooser.showOpenDialog(testFrame);
if(returnVal == JFileChooser.APPROVE_OPTION) {
TextField.setText(chooser.getSelectedFile().getAbsolutePath());
}
//--核心代码结束
}
});
Container contentPane=testFrame.getContentPane();
contentPane.setLayout(new FlowLayout());
contentPane.add(button);
contentPane.add(TextField);
testFrame.setSize(,);
testFrame.setVisible(true);
}}