map遍历

                // 1.KeySet
		Iterator<String> item = map.keySet().iterator();
		while(item.hasNext()){
			String key = item.next();
			String value = map.get(key);
		}
		
		for(String key: map.keySet()){
			String value = map.get(key);
		}
		
		// 2.entrySet
		Iterator<Entry<String,String>> entry = map.entrySet().iterator();
		while(entry.hasNext()){
			String key = entry.next().getKey();
			String value = entry.next().getValue();
		}
		
		for(Entry<String,String> entry1 : map.entrySet()){
			String key = entry1.getKey();
			String value = entry1.getValue();
		}