textfieldtest.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.awt.*;
import java.awt.event.*;
import javax.swing.*;
 public class TextFieldTest extends JFrame {
   private JLabel label1,label2;
   private JTextField textField1,textField2;
   private JPasswordField passwordField;
   private JTextArea textArea;
   public TextFieldTest(){
     super( "Testing JTextField and JPasswordField" );
     Container container = getContentPane();
     container.setLayout( new FlowLayout() );
     label1=new JLabel("Enter text here" );
     container.add(label1);
     textField1 = new JTextField( 10 );
     container.add( textField1 );
     label1=new JLabel("Enter password here" );
     container.add(label1);
     passwordField = new JPasswordField(10);
     container.add( passwordField );
     textField2 = new JTextField( "Uneditable text field", 20 );
     textField2.setEditable( false );
     container.add( textField2 );
     textArea=new JTextArea("This is a textarea",5,20);
     container.add(textArea);
     TextFieldHandler handler = new TextFieldHandler();
     textField1.addActionListener( handler );
     textField2.addActionListener( handler );
     passwordField.addActionListener( handler );
     setSize( 325, 230 );
     setVisible( true );
   }
  public static void main( String args[] ){
    TextFieldTest application = new TextFieldTest();
    application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
  }
  private class TextFieldHandler implements ActionListener {
    public void actionPerformed( ActionEvent event ){
      String string = "";
      if ( event.getSource() == textField1 )
      string = "textField1: " + event.getActionCommand();
      else if ( event.getSource() == textField2 )
        string = "textField2: " + event.getActionCommand();
      else if ( event.getSource() == passwordField ) {
        JPasswordField pwd =( JPasswordField ) event.getSource();
        string = "passwordField: " +new String( passwordField.getPassword() );
      }
      JOptionPane.showMessageDialog( null, string );
    }
  }
}