Java JList

Java JList

Java JList class inherits from JComponent class.It allows the user to select single or multiple items from a list.

How to Declare Java JList class

This is how java.swing.JList class is declared.

[pclass JList extends JComponent implements Scrollable, Accessible]

Used JList constructors

• JList()-creates empty read-only model JList.
• JList(array [] data)-creates a JList that display elements from a specified array.
• JList(ListModel<array> datamodel)-creates JList that display elements from a model.

JList commonly used methods

• void addListSelectionListener()-adds listener to a list and notifies once selection occurs.
• int getSelectedIndex()-returns smallest selected cell index.
• ListModel getModel()- gets model that holds list data.
• void setListData(Object [] data)-creates ListModel from array.

Java JList Example

[

import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.DefaultListModel;
public class JListExample extends JFrame{

    JListExample()
    {
        super("JFrame Example");

        DefaultListModel<String> model=new DefaultListModel();
        model.addElement("Mango");
        model.addElement("Orange");
        model.addElement("Banana");
        model.addElement("Watermelon");

        JList<String> list=new JList(model);

        list.setBounds(50,50, 75,75);
        add(list);
        setSize(400,400);
        setLayout(null);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }
    public static void main(String args[])
    {
        new JListExample();
    }

}

]

Java JList with ActionListener Example

[

import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.DefaultListModel;
import javax.swing.JLabel;
import javax.swing.JButton;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class JListExample extends JFrame implements ActionListener{
    public JList<String> list;
    public JLabel label;
    JListExample()
    {
        super("JFrame Example");

        DefaultListModel<String> model=new DefaultListModel();
        model.addElement("Mango");
        model.addElement("Orange");
        model.addElement("Banana");
        model.addElement("Watermelon");

        list=new JList(model);

        list.setBounds(50,100, 75,75);
        JButton b=new JButton("Show");
        b.setBounds(50, 200, 100, 30);
        b.addActionListener(this);

        add(b);



        add(list);
        label=new JLabel("Label");
        label.setBounds(50,50,300,50);
        add(label);

        setSize(400,400);
        setLayout(null);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }
    public static void main(String args[])
    {
        new JListExample();
    }

    public void actionPerformed(ActionEvent event)
    {
        String s="";
        if(list.getSelectedIndex()!=-1)
        {
            s="Fruit selected is "+list.getSelectedValue();
            label.setText(s);

        }
    }

}

]

Output:

See also:

Java JTable

Java JComboBox