JLabel Example in Java for Beginners

The following example illustrates JLabel example in Java swing for beginners. This example covers all the core methods of javax.swing.JLabel class.

import javax.swing.*;
import java.awt.*;
class JLabelExample extends JFrame
{
JTextField jt1,jt2;
JLabel l1,l2,l3,l4,l5,l6;
ImageIcon i1,i2,i3,i4,i5;
Font f;

    public JLabelExample()
    {
        createAndShowGUI();
    }
   
    private void createAndShowGUI()
    {
       
        // Set frame properties
        setTitle("JLabel Demo");
        setSize(400,400);
        setLayout(new FlowLayout());
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Create a font
        f=new Font("Myriad Pro",Font.PLAIN,22);
       
        // Create image icons
        i1=new ImageIcon("icon1.png");
        i2=new ImageIcon("icon2.png");
        i3=new ImageIcon("pictures.png");
        i4=new ImageIcon("finder.png");
        i5=new ImageIcon("picturesdisabled.png");
       
        // Create JTextFields
        jt1=new JTextField(20);
        jt2=new JTextField(20);
       
        // First constructor
        // Takes no parameter
        // JLabel comes with
        // no icon, text and enabled
        l1=new JLabel();
       
        // Second constructor
        // Takes an Icon
        l2=new JLabel(i1);
       
        // Third constructor
        // Takes icon and horizontal alignment
        // of the label
        l3=new JLabel(i2,SwingConstants.CENTER);
       
        // Fourth constructor
        // Takes String text that comes
        // on the JLabel
        l4=new JLabel("Label 4");
       
        // Fifth constructor
        // Takes String text with an icon and horizontal
        // alignment of label
        l5=new JLabel("Label 5",i3,SwingConstants.LEADING);
       
        // Sixth constructor
        // Takes String text with horizontal alignment
        l6=new JLabel("<html><h2>Label <u>6</u></h2></html>",SwingConstants.TRAILING);
       
        // Set some text
        l1.setText("Label 1");
        l2.setText("Label 2");
       
        // Get text
        System.out.println("Text on l1 is "+l1.getText());
        System.out.println("Text on l2 is "+l2.getText());
       
        // Set some font
        l1.setFont(f);
        l2.setFont(f);
       
        // Get font
        System.out.println("Font of l1 is "+l1.getFont());
        System.out.println("Font of l2 is "+l2.getFont());
       
        // Set icon
        l4.setIcon(i4);
       
        // Set icon text gap
        // Default value is 4
        // This is relative to
        // the alignment
        l4.setIconTextGap(8);
       
        // Get icon text gap
        System.out.println("Icon text gap for l4 is "+l4.getIconTextGap());
       
        // Set mnemonic
        // When user presses this key
        // with alt pressed, requestFocus()
        // is called on the corresponding
        // label
        l1.setDisplayedMnemonic('1');
        l2.setDisplayedMnemonic('2');
        l6.setDisplayedMnemonic((int)'6');
       
        // Get displayed mnemonics
        System.out.println("Displayed mnemonic for l1 is "+l1.getDisplayedMnemonic());
        System.out.println("Displayed mnemonic for l2 is "+l2.getDisplayedMnemonic());
        System.out.println("Displayed mnemonic for l5 is "+l6.getDisplayedMnemonic());
       
        // Set displayed mnemonic index
        // The character at this index
        // in JLabel will be underrlined
        //l6.setDisplayedMnemonicIndex(16);
       
        // Set vertical text position
        l4.setVerticalTextPosition(SwingConstants.BOTTOM);
       
        // Get vertical text position
        System.out.println("Vertical text position for l4 "+l4.getVerticalTextPosition());
       
        // Set horizontal text position
        l4.setHorizontalTextPosition(SwingConstants.CENTER);
       
        // Get horizontal text position
        System.out.println("Horizontal text position for l4 "+l4.getHorizontalTextPosition());
       
        // Now the text on l4 will appear
        // below the icon (vertical) and at
        // the center looks pretty much like desktop icon
       
        // Set label for some component.
        // Whenever the user fires the mnemonic
        // requestFocus() is called on the component
        // associated with the label provided that
        // the component is focusable
        // Otherwise, focus gets transferred to the
        // label itself
        l1.setLabelFor(jt1);
        l6.setLabelFor(jt2);

        // Set some background,foreground
        // to make alignment visible
       
        // Before setting background,
        // JLabel must be made opaque
        // By default isOpaque() returns false
       
        // Set opaque
        l6.setOpaque(true);
       
        // Print is opaque
        System.out.println("l6 is "+(l6.isOpaque()?"opaque":"not opaque"));
       
        // Set background,foreground
        l6.setBackground(Color.DARK_GRAY);
        l6.setForeground(Color.WHITE);
       
        // Get background,foreground
        System.out.println("Background for l6 is "+l6.getBackground());
        System.out.println("Foreground for l6 is "+l6.getForeground());
       
        // Also increase size
        l6.setPreferredSize(new Dimension(100,50));
       
        // Get preferred size
        System.out.println("The preferred size of l6 is "+l6.getPreferredSize());
       
        // Set vertical alignment
        l6.setVerticalAlignment(SwingConstants.TOP);
       
        // Get vertical alignment
        System.out.println("Vertical alignment of l6 is "+l6.getVerticalAlignment());
       
        // Set horizontal alignment
        l6.setHorizontalAlignment(SwingConstants.RIGHT);
       
        // Get horizontal alignment
        System.out.println("Horizontal alignment of l6 is "+l6.getHorizontalAlignment());
       
        // Disable l5
        l5.setEnabled(false);
       
        // is enabled
        System.out.println("l5 is "+(l5.isEnabled()?"enabled":"disabled"));
       
        // The icon is also greyed out
        // Alternatively, one can also
        // set disabled icon
        l5.setDisabledIcon(i5);
       
        // Add all components
        add(l1);
        add(jt1);
        add(l2);
        add(l3);
        add(l4);
        add(l5);
        add(l6);
        add(jt2);
    }   
   
    public static void main(String args[])
    {
        SwingUtilities.invokeLater(new Runnable(){
            public void run()
            {
                new JLabelExample();
            }
        });
    }
}

Screenshot of JLabel Example
 


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Tags: Swing Components,