filechooserdemo.java

java经典的源代码 我非常喜欢这个源代码 对于编程很有好处

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class fileChooserDemo extends JFrame {
 private ObjectInputStream input;
 private JButton openButton;
 public fileChooserDemo(){
   super( "File chooser" );
   openButton=new JButton( "Open File" );
   openButton.addActionListener(new ActionListener() {
     public void actionPerformed( ActionEvent event ){
       openFile();
     }
   }); // end call to addActionListener
   addWindowListener( new WindowAdapter() {
     public void windowClosing( WindowEvent event ){
       System.exit( 0 );
     }
   } );
   Container contentPane = getContentPane();
   contentPane.setLayout(new FlowLayout());
   contentPane.add(openButton);
   pack();
   setSize( 200, 100 );
   show();
 } // end ReadSequentialFile constructor
 private void openFile(){
   JFileChooser fileChooser = new JFileChooser();
   fileChooser.setFileSelectionMode( JFileChooser.FILES_ONLY );
   int result = fileChooser.showOpenDialog( this );
   if ( result == JFileChooser.CANCEL_OPTION )
     return;
   File fileName = fileChooser.getSelectedFile();
   if ( fileName == null || fileName.getName().equals( "" ) )
     JOptionPane.showMessageDialog(this,"Invalid File Name","Invalid File Name",JOptionPane.ERROR_MESSAGE );
   else {
     try {
       input = new ObjectInputStream(new FileInputStream( fileName ) );
       openButton.setEnabled( false );
     }
     catch ( IOException ioException ) {
       JOptionPane.showMessageDialog(this, "Error Opening File", "Error", JOptionPane.ERROR_MESSAGE );
     }
   } // end else
 }
 public static void main( String args[] ){
   fileChooserDemo app=new fileChooserDemo();
 }
}