如何使用swing/SWT，点一个按钮就能打开本地的一个文件？

Question

想用eclipse做一个可视化界面，使点击一个按钮就能打开本地已经存在的文件

Answer 1

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

public class wenjian
extends Frame
implements ActionListener {
FileDialog open = new FileDialog(this, "打开文件",
FileDialog.LOAD);
String fileName;
Button b_dakai = new Button("打开");
TextArea text = new TextArea();
wenjian() {
super("文件的打开");
setBounds(400, 200, 400, 300);
b_dakai.addActionListener(this);
add(text);
add(b_dakai, "South");
setVisible(true);
}

public void actionPerformed(ActionEvent e) {
if (e.getSource() == b_dakai) {
open.show();
fileName = open.getDirectory() + open.getFile();
if (fileName != null) {
readFile(fileName);
}
}
}

// 这是一个打开文件文件的方法
public void readFile(String fileName) {
try {
File file = new File(fileName);
FileReader readIn = new FileReader(file);
int size = (int) file.length();
int charsRead = 0;
char[] content = new char[size];
while (readIn.ready()) {
charsRead += readIn.read(content, charsRead, size - charsRead);
}
readIn.close();
text.setText(new String(content, 0, charsRead));
}
catch (IOException e) {
System.out.println("Error Opening file");
}
}

public static void main(String args[]) {
new wenjian().addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
};
});
;
}
}