JFileChooser 如何保存上次打开文件时的路径

转载：http://zhidao.baidu.com/link?url=mcf9LDgq-WC14HUooxYd80PsksD9O8tQnEL3eLnAdNBE05xU_BngIflQgd9J3KRsDSYGMRJ6sk0erXMI60XUy_
package itcast.cn.gui.JFileChooser;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
/**
* JFileChooser打开上次的路径
* @author windpower3
*
*/

public class FileChooser extends JFrame implements ActionListener {

private JButton open;
private JFileChooser chooser;
private String latestPath;
private Profile profile;

public FileChooser() {
profile = new Profile();// 每次运行程序时创建配置文件Profile对象
latestPath = (profile.read() ? profile.latestPath : "C:/");// 读取配置文件里的参数Profile并赋值给latestPath
open = new JButton("open");
this.add(open);
this.setSize(200, 150);
this.setLocationRelativeTo(null);// 窗口居中
this.setVisible(true);
open.addActionListener(this);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
profile.write(latestPath);// 每次退出程序时把最后一次打开的目录写入到配置文件
}
});
}

public static void main(String[] args) {
//    File f=new File("c:/users/windpower3/Pictures/4.png");
//    System.out.println(f.getParent());
new FileChooser();
}

@Override
public void actionPerformed(ActionEvent e) {
if (!new File(latestPath).exists()) {
latestPath = "C:/";
} else {
chooser = new JFileChooser(latestPath);
int returnVal = chooser.showOpenDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
File file = chooser.getSelectedFile();
// 其他操作...
latestPath = file.getParent();// 每次退出文件选择器后更新目录Properties
}

}

}

class Profile {
String latestPath = "C:/";
File file = new File("C:/JavaCode/FileChooser/set.ini");

public Profile() {
}

boolean create() {
boolean b = true;
if (file != null) {
File directory = file.getParentFile();// 获得文件的父目录
if (!directory.exists()) {// 目录不存在时
b = directory.mkdirs();// 创建目录
} else {// 存在目录
if (!file.exists()) {// 配置文件不存在时
try {
b = file.createNewFile();// 创建配置文件
} catch (IOException e) {
b = false;
}
}
}
}
return b;
}

boolean read() {
Properties pro;// 属性集
FileInputStream is = null;
boolean b = true;
if (!file.exists()) {// 配置文件不存在时
b = create();// 创建一个
if (b)// 创建成功后
b = write(latestPath);// 初始化
else// 创建失败即不存在配置文件时弹出对话框提示错误
JOptionPane.showConfirmDialog(null, "对不起，不存在配置文件！", "错误", JOptionPane.YES_NO_OPTION,
JOptionPane.ERROR_MESSAGE);
} else {
try {
is = new FileInputStream(file);
pro = new Properties();
pro.load(is);// 读取属性
latestPath = pro.getProperty("latestPath");// 读取配置参数latestPath的值
is.close();
} catch (IOException ex) {
ex.printStackTrace();
b = false;
}
}
return b;
}

boolean write(String latestPath) {
this.latestPath = latestPath;
Properties pro = null;
FileOutputStream os = null;
boolean b = true;
try {
os = new FileOutputStream(file);
pro = new Properties();

pro.setProperty("latestPath", latestPath);

pro.store(os, null); // 将属性写入
os.flush();
os.close();

System.out.println("latestPath=" + latestPath);

} catch (IOException ioe) {
b = false;
ioe.printStackTrace();
}
return b;
}
}
}