Java Program to set the extent in JSlider

To set the extent of the slider, use the setExtent() method. It sets the size of the range covered by the knob −

JSlider slider = new JSlider(JSlider.HORIZONTAL, 0, 100, 70);
slider.setMinorTickSpacing(5);
slider.setMajorTickSpacing(20);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.setExtent(20);

The following is an example to set the extent in JSlider −

Example

package my;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.WindowConstants;
public class SwingDemo {
   public static void main(String[] args) {
      JFrame frame = new JFrame("Frame with Slider");
      JSlider slider = new JSlider(JSlider.HORIZONTAL, 0, 100, 70);
      slider.setMinorTickSpacing(5);
      slider.setMajorTickSpacing(20);
      slider.setPaintTicks(true);
      slider.setPaintLabels(true);
      slider.setExtent(20);
      JPanel panel = new JPanel();
      panel.add(slider);
      frame.add(panel);
      frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      frame.setSize(500, 300);
      frame.setVisible(true);
   }
}

The output is as follows displaying the JSlide −

Now you can’t extend the JSlider to the end since you have set the extent above −