Java Swing, 2nd Edition

Labels

Swing allows you to create labels that can contain text, images, or both. We’ll begin this chapter with a look at the JLabel class.

The JLabel class allows you to add basic, noninteractive labels to a user interface. Because of its inherent simplicity, there is no model class for JLabel. Figure 4-1 shows a class diagram for JLabel. We’ll get into the two relationships to Icon a little later.

Figure 4-1. JLabel class diagram

JLabel objects may consist of both text and graphics (icons), but for simple text-only labels, the interface with JLabel is very similar to that of java.awt.Label. The code to create and display a very simple text label looks like this:

// SimpleJLabelExample.java
//
import javax.swing.*;

public class SimpleJLabelExample {
  public static void main(String[] args) {
    JLabel label = new JLabel("A Very Simple Text Label");

    JFrame frame = new JFrame( );
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane( ).add(label); // Adds to CENTER
    frame.pack( );
    frame.setVisible(true);
  }
}

Running this simple program produces the display shown in Figure 4-2.

Figure 4-2. A simple JLabel

Properties

The JLabel class contains the properties shown in Table 4-1. The icon and disabledIcon properties specify the icon to be displayed by default and when the label ...