JLabel lblPrimeNumberChecker = new JLabel("Prime number checker");
    lblPrimeNumberChecker.setBounds(160, 11, 117, 14);
    contentPane.add(lblPrimeNumberChecker);


    JButton btnReset = new JButton("Reset");
    btnReset.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            textNum.setText(null);

        }
    });
    btnReset.setBounds(271, 208, 89, 23);
    contentPane.add(btnReset);

    textNum = new JTextField();
    textNum.setBounds(144, 42, 231, 20);
    contentPane.add(textNum);
    textNum.setColumns(10);

    JLabel lblNewLabel = new JLabel("Enter number");
    lblNewLabel.setBounds(62, 45, 82, 14);
    contentPane.add(lblNewLabel);

    JButton btnCheck = new JButton("Check");
    btnCheck.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseClicked(MouseEvent checkPrime) {

        }
        private boolean checkPrime(int n) {
            int num=Integer.parseInt(textNum.getText());
             if(num<2) {
                 return false;
             }
             int h=(int)Math.sqrt(n);
             for(int i=2;i<=h;i++) {
                 if(n%i==0) {
                     return false;
                 }
             }
                    return true;


        }
            void button_clicked() {
                int n=0;
                boolean isPrime=checkPrime(n);
                if(isPrime) {
                    JOptionPane.showMessageDialog(btnCheck, "Prime number", "Result", JOptionPane.INFORMATION_MESSAGE);
                }
                else {
                    JOptionPane.showMessageDialog(btnCheck, "Not prime number", "Result", JOptionPane.INFORMATION_MESSAGE);
                }
            }


            });
    btnCheck.setBounds(62, 208, 89, 23);
    contentPane.add(btnCheck);