JList basic tutorial and examples

countryList.addListSelectionListener(new ListSelectionListener() { 
    @Override 
    public void valueChanged(ListSelectionEvent e) 
    { 
        if(!e.getValueIsAdjusting()) { 
            final List<String> selectedValuesList = countryList.getSelectedValuesList(); 
            System.out.println(selectedValuesList); 
        } 
    } 
});    

The above code registers a ListSelectionListener using the addListSelectionListener() method. We use an anonymous inner class to implement the event listener interface. We implement the valueChanged() method. We call the handy method getSelectedValuesList() on the JList instance which returns a List<String>, as in our case, we had declared the JList to contain only String values. For illustration purposes, we simply print this list on the console which prints the list of values selected.

Now, run the program and select a few items (single, multiple, contiguous, non-contiguous) and check the output on the console. Now, deselect all items in the list and check the output on the console. It will print an empty list.

We use extra if condition in the code which checks if the list is still adjusting the status. If it is not, we retrieve the selected items.

Here is the full source code of our GUI:

package net.codejava.swing;

import java.util.List;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

/**
 * JList basic tutorial and example
 *
 * @author wwww.codejava.net
 */
public class JListExample extends JFrame {

    private JList<String> countryList;

    public JListExample() {
        //create the model and add elements
        DefaultListModel<String> listModel = new DefaultListModel<>();
        listModel.addElement("USA");
        listModel.addElement("India");
        listModel.addElement("Vietnam");
        listModel.addElement("Canada");
        listModel.addElement("Denmark");
        listModel.addElement("France");
        listModel.addElement("Great Britain");
        listModel.addElement("Japan");

        //create the list
        countryList = new JList<>(listModel);
        countryList.addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent e) {
                if (!e.getValueIsAdjusting()) {
                    final List<String> selectedValuesList = countryList.getSelectedValuesList();
                    System.out.println(selectedValuesList);
                }
            }
        });

        add(new JScrollPane(countryList));

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("JList Example");
        this.setSize(200, 200);
        this.setLocationRelativeTo(null);
        this.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new JListExample();
            }
        });
    }
}

Other Java Swing Tutorials:

• Java Swing Hello World Tutorial for Beginners Using Text Editor
• JFrame basic tutorial and examples
• JPanel basic tutorial and examples
• JLabel basic tutorial and examples
• JTextField basic tutorial and examples
• JButton basic tutorial and examples
• JComboBox basic tutorial and examples
• JCheckBox basic tutorial and examples
• JTree basic tutorial and examples

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