How to disable close button on a JFrame in Java?

To disable the close button, let us first create a frame −

JFrame frame = new JFrame("Login!");

Use the setDefaultCloseOperation() to set the status of the close button. Set it to DO_NOTHING_ON_CLOSE to disable it −

frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

The following is an example to disable close button on a JFrame in Java −

Example

package my; import java.awt.GridLayout; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPasswordField; import javax.swing.JTextField; import javax.swing.SwingConstants; public class SwingDemo {    public static void main(String[] args) throws Exception {       JFrame frame = new JFrame("Login!");       JLabel label1, label2, label3;       frame.setLayout(new GridLayout(2, 2));       label1 = new JLabel("DeptId", SwingConstants.CENTER);       label2 = new JLabel("SSN", SwingConstants.CENTER);       label3 = new JLabel("Password", SwingConstants.CENTER);       JTextField deptid = new JTextField(20);       JTextField ssn = new JTextField(20);       JPasswordField passwd = new JPasswordField();       passwd.setEchoChar('*');       frame.add(label1); frame.add(label2); frame.add(label3); frame.add(deptid); frame.add(ssn); frame.add(passwd);       frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); frame.setSize(550, 400);       frame.setVisible(true);    } }

The output is as follows displaying the close button but it won’t work since we disabled it above −

Output