java.util.WeakHashMap.entrySet() 方法

package com.codingdict;

import java.util.Map;
import java.util.Set;
import java.util.WeakHashMap;

public class WeakHashMapDemo {
   public static void main(String[] args) {
   Map<String, String> weakHashMap = new WeakHashMap<String, String>();

      // put keys and values in the Map      
      weakHashMap.put("1", "first");
      weakHashMap.put("2", "two");
      weakHashMap.put("3", "three");

      // printing the Map
      System.out.println("Map: "+weakHashMap);

      // returns a Set view of the Map
      Set set = weakHashMap.entrySet();

      // printing the set
      System.out.println("Set: "+set);

      // change Map value
      System.out.println("Changing map");
      weakHashMap.put("3", "new value");

      // print Map and set
      System.out.println("Changed Map: "+weakHashMap);
      System.out.println("Changed Set: "+set);
   }     
}