How to set vertical alignment for a component in Java?

For vertical alignment, create a frame and set the layout using the BoxLayout manager −

JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));

Above, we have set the BoxLayout to set the alignment since it is a layout manager that allows multiple components to be laid out either vertically or horizontally. We have set vertical alignment here −

BoxLayout.X_AXIS

The following is an example to set vertical alignment for a component −

Example

package my;
import java.awt.Component;
import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class SwingDemo {
   public static void main(String[] args) {
      JFrame frame = new JFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
      JPanel panel = new JPanel();
      JButton btn1 = new JButton("Clear");
      JButton btn2 = new JButton("Reset");
      JButton btn3 = new JButton("Submit");
      panel.add(btn1);
      panel.add(btn2);
      panel.add(btn3);
      panel.setAlignmentX(Component.LEFT_ALIGNMENT);
      panel.setPreferredSize(new Dimension(100, 500));
      panel.setMaximumSize(new Dimension(100, 500));
      panel.setBorder(BorderFactory.createTitledBorder("demo"));
      frame.getContentPane().add(panel);
      frame.setSize(550, 300);
      frame.setVisible(true);
   }
}

Output