Java JPanel Basic Tutorial

JPanel Basic Tutorial

Java JPanel is a container class that provides space for application to attach other components.This class it inherits from JComponent class.
Note that JPanel class has no menubar like JFrame JMenuBar.

How to declare Java JPanel class

[class JPanel extends JComponent implements Accessible
 

]

Java JPanel Constructors

• JPanel()-creates a JPanel with a doule buffer and flow layout.
• JPanel(boolean isBuffered)-creates JPanel with flowLayout and specified buffering strategy.
• JPanel(LayoutManager layout)-create JPanel with specified Layout.

Java JPanel Example

[

/** * This program creates A JFrame and adds JPanel  

* with two buttons

 * * @author Eric */

import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
public class JavaJPanel extends JFrame {
    JavaJPanel()
    {
        super("JFrame Example");
        JPanel panel=new JPanel();

        panel.setBounds(10,20,200,100);
        panel.setBackground(Color.BLUE);
        JButton b1=new JButton("Button 1");
        b1.setBounds(10,100,80,30);
        b1.setBackground(Color.PINK);
        JButton b2=new JButton("Button 2");
        b2.setBounds(100,100,80,30);
        b2.setBackground(Color.MAGENTA);
        panel.add(b1); panel.add(b2);
        add(panel);
        setSize(300,200);
        setLocationRelativeTo(null);
        setLayout(null);
        setVisible(true);



    }
    public static void main(String args[])
    {
        new JavaJPanel();
    }

}

]

Java JPanel Example adding ActionListener

[

/** * This program creates A JFrame and adds JPanel 

 * with two buttons which implement ActionListener *

 * @author Eric */

import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JOptionPane;
public class JavaJPanel extends JFrame implements ActionListener{
    public   JButton b1,b2;
    JavaJPanel()
    {
        super("JFrame Example");
        JPanel panel=new JPanel();

        panel.setBounds(10,20,150,100);
        panel.setBackground(Color.BLUE);
        b1=new JButton("Button 1");
        b1.setBounds(10,100,80,30);
        b1.setBackground(Color.PINK);
        b1.addActionListener(this);

        b2=new JButton("Button 2");
        b2.addActionListener(this);
        b2.setBounds(100,100,80,30);
        b2.setBackground(Color.MAGENTA);
        panel.add(b1); panel.add(b2);
        add(panel);
        setSize(300,200);
        setLocationRelativeTo(null);
        setLayout(null);
        setVisible(true);
    }
    public void actionPerformed(ActionEvent evt)
    {
        if(evt.getSource()==b1)
        {
            JOptionPane.showMessageDialog(this,"You clicked Button 1",
                    "JPanel Example",JOptionPane.INFORMATION_MESSAGE);
        }

        if(evt.getSource()==b2)
        {
            JOptionPane.showMessageDialog(this,"You clicked Button 2",
                    "JPanel Example",JOptionPane.INFORMATION_MESSAGE);
        }

    }
    public static void main(String args[])
    {
        new JavaJPanel();
    }

}

]

Related Tutorials

• JOptionPane Examples

• Add actionListener to JButton

• Simple Java JDialog Example