SWING - JFrame Class

Introduction

The class JFrame is an extended version of java.awt.Frame that adds support for the JFC/Swing component architecture.

Class Declaration

Following is the declaration for javax.swing.JFrame class −

public class JFrame
   extends Frame
      implements WindowConstants, Accessible, RootPaneContainer

Field

Following are the fields for java.awt.Component class −

• protected AccessibleContext accessibleContext −The accessible context property.

• static int EXIT_ON_CLOSE − The exit application default window close operation.

• protected JRootPane rootPane − The JRootPane instance that manages the contentPane and optional menuBar for this frame, as well as the glassPane.

• protected boolean rootPaneCheckingEnabled − If true then calls to add and setLayout will be forwarded to the contentPane.

Class Constructors

Class Methods

Methods Inherited

This class inherits methods from the following classes −

• java.awt.Frame
• java.awt.Window
• java.awt.Container
• java.awt.Component
• java.lang.Object

JFrame Example

Create the following Java program using any editor of your choice in say D:/ > SWING > com > tutorialspoint > gui >

SwingContainerDemo.java

package com.tutorialspoint.gui;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SwingContainerDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;
   private JLabel msglabel;

   public SwingContainerDemo(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingContainerDemo  swingContainerDemo = new SwingContainerDemo();  
      swingContainerDemo.showJFrameDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java Swing Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new JLabel("", JLabel.CENTER);        
      statusLabel = new JLabel("",JLabel.CENTER);    
      statusLabel.setSize(350,100);
      msglabel = new JLabel("Welcome to TutorialsPoint SWING Tutorial.", JLabel.CENTER);

      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showJFrameDemo(){
      headerLabel.setText("Container in action: JFrame");   
      final JFrame frame = new JFrame();
      frame.setSize(300, 300);
      frame.setLayout(new FlowLayout());       
      frame.add(msglabel);
      
      frame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            frame.dispose();
         }        
      });    
      JButton okButton = new JButton("Open a Frame");
      okButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            statusLabel.setText("A Frame shown to the user.");
            frame.setVisible(true);
         }
      });
      controlPanel.add(okButton);
      mainFrame.setVisible(true);  
   }
}

Compile the program using the command prompt. Go to D:/ > SWING and type the following command.

D:\SWING>javac com\tutorialspoint\gui\SwingContainerDemo.java

If no error occurs, it means the compilation is successful. Run the program using the following command.

D:\SWING>java com.tutorialspoint.gui.SwingContainerDemo

Verify the following output.