TanSanC

import javax.swing.*;

import java.awt.event.*;

class MyFrame extends JFrame {

       private JButton button;

       private JTextField text, result;

       public MyFrame() {

             setSize(300, 130);

             setTitle("제곱 계산하기");

             setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

             ButtonListener listener = new ButtonListener();   // 리스너 객체 생성

             JPanel panel = new JPanel();

             panel.add(new JLabel("숫자 입력: "));    // 레이블 생성

             text = new JTextField(15);       // 컬럼수가 15인 텍스트 필드 생성

             text.addActionListener(listener);   // 텍스트 필드에 리스너 연결

             panel.add(text);

             panel.add(new JLabel("제곱한 값: "));

             result = new JTextField(15); // 결과를 나타낼 텍스트 필드 

             result.setEditable(false);       // 편집 불가 설정

             panel.add(result);

           button = new JButton("OK");

           button.addActionListener(listener);

           panel.add(button);

           add(panel);

           setVisible(true);

     }

     // 텍스트 필드와 버튼의 액션 이벤트 처리

     private class ButtonListener implements ActionListener {

           public void actionPerformed(ActionEvent e) {

                  if (e.getSource() == button || e.getSource() == text) {

                         String name = text.getText();

                         int value = Integer.parseInt(name);

                         boolean isPrimeNumber = false;

                         // 계산

                         int count = 0;

                         for( int i = 1 ; i <= value ; i++)

                         {

                         //계산

                         if( value % i == 0)

                         {

                             count++;

                         }

                         }

                         if(count == 2)

                         {

                         isPrimeNumber = true;

                         }

                         if(isPrimeNumber)

                         {

                         result.setText("소수입니다.");

                         }

                         else

                         {

                         result.setText("소수가 아닙니다.");

                         }

                         text.requestFocus();

                  }

           }

     }

}

public class TextFieldTest extends JFrame {

     public static void main(String[] args) {

           new MyFrame();

     }

}