JList with a DefaultListModel||Java Codes

JList with a DefaultListModel||Java Codes

 DefaultListModel is a ListModel implementation that extends from AbstractListModel class.Below program is example of how you can implement DefaultListModel in a JList

JList with a DefaultListMode Example

[

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JList;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JScrollPane;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JOptionPane;


public class DefaultListModelExample  extends JPanel{

    public JList list;
    public JButton addB,removeB;
    public static JFrame f;
    public DefaultListModel m;
    DefaultListModelExample()
    {
        m=new DefaultListModel();
        list=new JList(m);


        JScrollPane pane = new JScrollPane(list);
        add(pane);
        addB=new JButton("Add");
        addB.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent event)
            {
                String s=JOptionPane.showInputDialog(null,
                        "Enter your favourite programming language",
                        "",JOptionPane.INFORMATION_MESSAGE);
                m.add(0,s);


            }

        });

        add(addB);

        removeB=new JButton("Remove");
        removeB.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent event )
            {
                m.removeElementAt(0);
            }
        });

        add(pane, BorderLayout.NORTH);
        add(addB, BorderLayout.WEST);
        add(removeB, BorderLayout.EAST);

    }
    public static void main(String args[])
    {
        f=new JFrame(" DefaultListModelExample ");
        f.setContentPane(new  DefaultListModelExample ());
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(300,230);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

}

]

Code Explanation

Above class extends JPanel.Code [ f.setContentPane(new DefaultListModelExample ());] gets all JPanel contents and displays them.

The class has two JButtons.One button addElement to DefaultListModel while the other JButton removeElementAt index 0.

Code to addElement at Index 0 is [addB.addActionListener(new ActionListener()

        {
            public void actionPerformed(ActionEvent event)
            {
                String s=JOptionPane.showInputDialog(null,
                        "Enter your favourite programming language",
                        "",JOptionPane.INFORMATION_MESSAGE);
                m.add(0,s);


            }

        });]

[JOptionPane.showInputDialog]-gets the string to be added to DefaultListModel.

Code to remove Element at index 0 is [removeB.addActionListener(new ActionListener()

        {
            public void actionPerformed(ActionEvent event )
            {
                m.removeElementAt(0);
            }
        });

      

    }]

[setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);]-closes JFrame and exits application when close button is clicked.

[ add(pane, BorderLayout.NORTH);

        add(addB, BorderLayout.WEST);

        add(removeB, BorderLayout.EAST);]-this is the code that setLayout of components in JPanel.