Map.Entry遍历集合中的元素Entry是Map中的一个内部累，map.entrySet()可以得到key和value的视图给你一个比较简单的小事例public static void main(String[] args) {Map map = new HashMap();map.put("key1", "value1");map.put("key2", "value2");map.put("key3", "value3");map.put("key4", "value4");Set set = map.keySet();//将map的kye放到set里了Iterator iter = set.iterator();while(iter.hasNext()){String key = (String)iter.next();System.out.PRintln("key=" + key + " value=" + map.get(key));}System.out.println("----------------------------------------------------");Iterator iter1 = map.entrySet().iterator();while(iter1.hasNext()){Map.Entry me = (Map.Entry)iter1.next();System.out.println("key=" + me.getKey() + " value=" + me.getValue());}}