GUI Notepad Sample

import java.awt.BorderLayout;

import java.awt.EventQueue;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.border.EmptyBorder;

import javax.swing.JButton;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import javax.swing.JTextArea;

import java.io.*;

import javax.swing.*;

public class Notepad extends JFrame {

String str;

private JPanel contentPane;

public static void main(String[] args) {

EventQueue.invokeLater(new Runnable() {

public void run() {

try {

Notepad frame = new Notepad();

frame.setVisible(true);

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

public Notepad() {

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 450, 300);

contentPane = new JPanel();

contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

setContentPane(contentPane);

contentPane.setLayout(null);

JTextArea textArea = new JTextArea();

textArea.setLineWrap(true);

textArea.setBounds(19, 19, 406, 218);

contentPane.add(textArea);

try {

File inFile = new File("notepad.txt");

FileReader fileReader = new FileReader(inFile);

BufferedReader bufReader = new BufferedReader(fileReader);

String tmp = "";

while (true) {

str = bufReader.readLine();

if(str == null) {

break;

}

tmp = tmp + str + "\n";

}

str = tmp;

bufReader.close();

} catch (IOException e) {

System.out.println("File error");

}

textArea.setText(str);

JScrollPane jsp = new JScrollPane(textArea);

jsp.setBounds(61, 41, 330, 182);

contentPane.add(jsp);

JButton btnBack = new JButton("Save");

btnBack.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

str = textArea.getText();

try {

File outFile = new File("notepad.txt");

FileOutputStream outFileStream = new FileOutputStream(outFile);

PrintWriter outStream = new PrintWriter(outFileStream);

outStream.println(str);

JOptionPane.showMessageDialog(null, "File Saved: " + str);

outStream.close();

} catch (IOException e1) {

System.out.println("File error");

}

}

});

btnBack.setBounds(108, 235, 117, 29);

contentPane.add(btnBack);

JButton btnClear = new JButton("Exit");

btnClear.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

System.exit(0);

}

});

btnClear.setBounds(237, 235, 117, 29);

contentPane.add(btnClear);

}

}