SpotBugs - WMI_WRONG_MAP_ITERATOR

Description

WMI: Method makes inefficient use of keySet iterator instead of entrySet iterator

This method accesses the value of a Map entry, using a key that was retrieved from a keySet iterator. It is more efficient to use an iterator on the entrySet of the map, to avoid the Map.get(key) lookup.

先取得keyset去做loop，再透過key去找對應value，造成每次都需要做搜尋的動作。

Solution

要看Code的實做方式決定如何修改。如果loop內要用到value與key，可以用entrySet取代使用keySet的lookup；如果只用到value或key，我認為可以用valueset或keyset取代。

Example

Before:

		for (String id: users.keySet()){
			IUser user = users.get(id);
			logger.debug("check user {} info.", id);
			validateUserInfo(result, user);
		}

After:

		for(  Entry<String, IUser> entry : users.entrySet()){
			logger.debug("check user {} info.", entry.getKey());
			validTimeRanges(result, entry.getValue());
		}