Đề 6 KMA

import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class De6 extends Frame implements ActionListener {

    private Label lbForm, lbUser, lbPass;
    private TextField tfUser, tfPass;
    private Button btRegister, btCancel;
    private GridBagLayout gb;
    private GridBagConstraints gbc;

    public De6(String title) {
        super(title);
        this.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent we) {
                System.exit(0);
            }
        });
        lbForm = new Label("Form Test");
        lbUser = new Label("Name:");
        lbPass = new Label("Password:");
        tfUser = new TextField(20);
        tfPass = new TextField(20);
        tfPass.setEchoChar('*');
        btRegister = new Button("Register");
        btCancel = new Button("Cancel");

        gb = new GridBagLayout();
        this.setLayout(gb);
        Them(lbForm,1,0,2,1);
        Them(lbUser,0,1,1,1);
        Them(tfUser,1,1,2,1);
        Them(lbPass,0,2,1,1);
        Them(tfPass,1,2,2,1);
        Them(btRegister,1,3,1,1);
        Them(btCancel,2,3,1,1);

        btRegister.addActionListener(this);
        btCancel.addActionListener(this);
    }

    public void Them(Component comp, int x, int y, int rong, int cao) {
        gbc = new GridBagConstraints();
        gbc.gridx = x;
        gbc.gridy = y;
        gbc.gridwidth = rong;
        gbc.gridheight = cao;
        gb.setConstraints(comp, gbc);
        this.add(comp);
    }

    public void GhiFile(File f) {
        try {
            FileWriter fw = new FileWriter(f);
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(tfUser.getText());
            bw.write("\n");
            bw.write(tfPass.getText());
            bw.close();
            fw.close();
        }
        catch (Exception ex) {
            System.out.println ("Loi roi");
        }
    }

    public void actionPerformed(ActionEvent ae) {
        if (ae.getSource() == btRegister) {
            File file = new File("login.txt");
            GhiFile(file);
        }
        if (ae.getSource() == btCancel) {
            tfUser.setText("");
            tfPass.setText("");
        }
    }

    public static void main(String[] args) {
        De6 fr = new De6("De 6 - Form Test");
        fr.setSize(300,200);
        fr.setVisible(true);
    }
}