遍历Map集合的方法

创建一个MAP的栗子:

        Map<String, Integer> tempMap = new HashMap<String, Integer>();
        tempMap.put("abc", 1);
        tempMap.put("aoe", 2);
        tempMap.put("xyz", 3);

方法一:

        Iterator<Entry<String, Integer>> it = tempMap.entrySet().iterator();
        while (it.hasNext()) {
            Entry<String, Integer> entry = it.next();
            Object key = entry.getKey();
            Object value = entry.getValue();
            System.out.println("key=" + key + " value=" + value);
        }

方法二:

        for (Map.Entry<String, Integer> entry : tempMap.entrySet()) {
            String key = entry.getKey().toString();
            String value = entry.getValue().toString();
            System.out.println("key=" + key + " value=" + value);
        }

方法三:

        for (Iterator<String> i = tempMap.keySet().iterator(); i.hasNext();) {
            Object obj = i.next();
            System.out.println(obj);
            System.out.println("key=" + obj + " value=" + tempMap.get(obj));
        }
        for (Iterator<Integer> i = tempMap.values().iterator(); i.hasNext();) {
            Object obj = i.next();
            System.out.println(obj);
        }

方法四:

        for (Object o : tempMap.keySet()) {
            System.out.println("key=" + o + " value=" + tempMap.get(o));
        }