TextFieldFrame.java

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;

public class TextFieldFrame extends JFrame 
{
   private JTextField textField1; // text field with set size
   private JTextField textField2; // text field constructed with text
   private JTextField textField3; // text field with text and size
   private JPasswordField passwordField; // password field with text

   // TextFieldFrame constructor adds JTextFields to JFrame
   public TextFieldFrame()
   {
      super( "Testing JTextField and JPasswordField" );
      setLayout( new FlowLayout() ); // set frame layout

      // construct textfield with 10 columns
      textField1 = new JTextField( 10 ); 
      add( textField1 ); // add textField1 to JFrame

      // construct textfield with default text
      textField2 = new JTextField( "Enter text here" );
      add( textField2 ); // add textField2 to JFrame

      // construct textfield with default text and 21 columns
      textField3 = new JTextField( "Uneditable text field", 21 );
      textField3.setEditable( false ); // disable editing
      add( textField3 ); // add textField3 to JFrame

      // construct passwordfield with default text
      passwordField = new JPasswordField( "Hidden text" );
      add( passwordField ); // add passwordField to JFrame

      // register event handlers
      TextFieldHandler handler = new TextFieldHandler();
      textField1.addActionListener( handler );
      textField2.addActionListener( handler );
      textField3.addActionListener( handler );
      passwordField.addActionListener( handler );
   } // end TextFieldFrame constructor

   // private inner class for event handling
   private class TextFieldHandler implements ActionListener 
   {
      // process textfield events
      public void actionPerformed( ActionEvent event )
      {
         String string = ""; // declare string to display

         // user pressed Enter in JTextField textField1
         if ( event.getSource() == textField1 )
            string = String.format( "textField1: %s",
               event.getActionCommand() );

         // user pressed Enter in JTextField textField2
         else if ( event.getSource() == textField2 )
            string = String.format( "textField2: %s",
               event.getActionCommand() );

         // user pressed Enter in JTextField textField3
         else if ( event.getSource() == textField3 )
            string = String.format( "textField3: %s", 
               event.getActionCommand() );

         // user pressed Enter in JTextField passwordField
         else if ( event.getSource() == passwordField )
            string = ( "passwordField: " + event.getActionCommand() );

         // display JTextField content
         JOptionPane.showMessageDialog( null, string ); 
      } // end method actionPerformed
   } // end private inner class TextFieldHandler
} // end class TextFieldFrame

TextFieldTest.java

import javax.swing.JFrame;

public class TextFieldTest
{
   public static void main( String[] args )
   { 
      TextFieldFrame textFieldFrame = new TextFieldFrame(); 
      textFieldFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
      textFieldFrame.setSize( 350, 100 ); // set frame size
      textFieldFrame.setVisible( true ); // display frame
   } // end main
} // end class TextFieldTest