Automatically Removing an Unreferenced Element from a Hash Table : Map « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. Map

import java.util.Iterator;
import java.util.Map;
import java.util.WeakHashMap;

public class Main {
  public static void main(String[] argv) throws Exception {
    Map weakMap = new WeakHashMap();
    Object keyObject = "";
    Object valueObject = "";
    weakMap.put(keyObject, valueObject);

    Iterator it = weakMap.keySet().iterator();
    while (it.hasNext()) {
      Object key = it.next();
    }
  }
}