文件的读与写

Happy boy：

老师布置的作业，写的不是很好哦，仅供参考！

求大师指点。

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.*;

import javax.swing.*;

class IO extends JFrame implements ActionListener {

JButton button1, button2;

JTextArea text;

JPanel pan1, pan2;

public IO() {

super("TF");

button1 = new JButton("打开文件");

button2 = new JButton("写入文件");

button1.addActionListener(this);//添加事件监听器

button2.addActionListener(this);

text = new JTextArea(15, 30);

text.setBounds(10, 10, 150, 100);

text.setEnabled(true);

JScrollPane scr = new JScrollPane(text,//加入滚动条

JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,

JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

pan1 = new JPanel();

pan2 = new JPanel();

pan1.setLayout(new FlowLayout());

pan1.add(button1);

pan1.add(button2);

// pan2.add(text);

add(pan1, BorderLayout.NORTH);

add(pan2, BorderLayout.CENTER);

pan2.add(scr);

setBounds(200, 300, 400, 400);

setVisible(true);

}

public void write(String str) {//写入文件

File file = new File("d:" + File.separator + "test.txt");

OutputStream out = null;

try {

out = new FileOutputStream(file, true);

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

byte b[] = str.getBytes();

try {

out.write(b);

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

try {

out.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public byte[] read() {//读出文件

File file = new File("d:" + File.separator + "test.txt");

InputStream in = null;

try {

in = new FileInputStream(file);

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

byte b[] = new byte[(int) file.length()];

try {

in.read(b);

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

try {

in.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return b;

}

@Override

public void actionPerformed(ActionEvent e) {//事件处理函数

// TODO Auto-generated method stub

if (e.getSource() == button1) {

String str2;

str2 = new String(read());

text.setText(str2);

} else if (e.getSource() == button2) {

String str1 = text.getText();

write(str1);

}

}

}

public class IoExperiment {//主类

public static void main(String[] args) {

IO io = new IO();

}

}