在java中怎样把文本区域里的内容保存成txt格式的文件

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import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class Test extends JFrame {

private static final long serialVersionUID = 1L;
private JTextArea txtArea;

private BufferedWriter buf;

public static void main(String args[]) {
try {
Test frame = new Test();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}

public Test() {
super();
getContentPane().setLayout(null);
setName("frame");
setResizable(false);
setTitle("Test");
setBounds(100, 100, 300, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

txtArea = new JTextArea();
txtArea.setBounds(48, 54, 200, 63);
getContentPane().add(txtArea);

final JButton btn = new JButton();
btn.addActionListener(new ActionListener() {
public void actionPerformed(final ActionEvent e) {
try {
buf = new BufferedWriter(new FileWriter("祥含F:\\test.txt"));
String str = txtArea.getText();
buf.write(str);
buf.flush();
} catch (IOException e1) {
e1.printStackTrace();
}
}
});
btn.setText("竖宴没余纳Save");
btn.setBounds(95, 149, 106, 26);
getContentPane().add(btn);
}
}

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import java.io.BufferedWriter;
import java.io.FileWriter;

public class Test {
public static void main(String[] args) throws Exception {
String txt = "文慧弊本内型碧禅容";
BufferedWriter writer = new BufferedWriter(new FileWriter("aa.txt"卜尘));
writer.write(txt);
writer.flush();
writer.close();
}
}

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