Java使用Preference类保存上一次记录的方法

import java.util.prefs.Preferences;
public class PreferrenceTest { 
private Preferences prefs;
public void setPreference() { 
// This will define a node in which the preferences can be stored 
prefs = Preferences.userRoot().node(this.getClass().getName()); 
String ID1 = "Test1"; 
String ID2 = "Test2"; 
String ID3 = "Test3";
// First we will get the values 
// Define a boolean value 
System.out.println(prefs.getBoolean(ID1, true)); 
// Define a string with default "Hello World 
System.out.println(prefs.get(ID2, "Hello World")); 
// Define a integer with default 50 
System.out.println(prefs.getInt(ID3, 50));
// Now set the values 
prefs.putBoolean(ID1, false); 
prefs.put(ID2, "Hello Europa"); 
prefs.putInt(ID3, 45);
// Delete the preference settings for the first value 
prefs.remove(ID1); 
System.out.println(prefs.get(ID2, "")); 
}
public static void main(String[] args) { 
PreferrenceTest test = new PreferrenceTest(); 
test.setPreference(); 
} 
}

Preferences pref = Preferences.userRoot().node(this.getClass().getName()); 
String lastPath = pref.get("lastPath", ""); 
   JFileChooser chooser = null; 
   if(!lastPath.equals("")){ 
   chooser = new JFileChooser(lastPath); 
   } 
   else 
   chooser=new JFileChooser();
//MyFileFilter 是自己写的一个文件过滤类，只接受xls格式文件
    MyFileFilter filter = new MyFileFilter("xls","只接受xls格式文件,即Excel 2003版文件");
   chooser.setFileFilter(filter);
 int state; //文件选择器返回状态
 state=chooser.showOpenDialog(null);//显示打开文件对话框
 File file = chooser.getSelectedFile(); //得到选择的文件
 pref.put("lastPath",file.getPath());
import java.io.File;
import javax.swing.filechooser.FileFilter;
//文件过滤器
public class MyFileFilter extends FileFilter
{
 public String ends; //文件后缀
 public String description; //文件描述文字
  public MyFileFilter (String ends, String description)
  { //构造函数
    this.ends = ends; //设置文件后缀
    this.description=description; //设置文件描述文字
  }
  public boolean accept (File file)
  { //重载FileFilter中的accept方法
    if (file.isDirectory ()) //如果是目录,则返回true
      return true;
    String fileName = file.getName (); //得到文件名称
    if (fileName.toUpperCase ().endsWith (ends.toUpperCase ()))
    //把文件后缀与可接受后缀转成大写后比较
      return true;
    else
      return false;
  }
 public String getEnds() {
 return ends;
 }
 public void setEnds(String ends) {
 this.ends = ends;
 }
 public String getDescription() {
 return description;
 }
 public void setDescription(String description) {
 this.description = description;
 }
}