preferencesdemo.java

Thinking in JAVA第四版源代码

//: io/PreferencesDemo.java
import java.util.prefs.*;
import static net.mindview.util.Print.*;

public class PreferencesDemo {
  public static void main(String[] args) throws Exception {
    Preferences prefs = Preferences
      .userNodeForPackage(PreferencesDemo.class);
    prefs.put("Location", "Oz");
    prefs.put("Footwear", "Ruby Slippers");
    prefs.putInt("Companions", 4);
    prefs.putBoolean("Are there witches?", true);
    int usageCount = prefs.getInt("UsageCount", 0);
    usageCount++;
    prefs.putInt("UsageCount", usageCount);
    for(String key : prefs.keys())
      print(key + ": "+ prefs.get(key, null));
    // You must always provide a default value:
    print("How many companions does Dorothy have? " +
      prefs.getInt("Companions", 0));
  }
} /* Output: (Sample)
Location: Oz
Footwear: Ruby Slippers
Companions: 4
Are there witches?: true
UsageCount: 53
How many companions does Dorothy have? 4
*///:~