log4j. properties 에서 log4j. rootLogger 와 log4j. rootCategory 는 어떤 차이 가 있 습 니까?

원본 주소:http://blog.csdn.net/caolaosanahnu/article/details/7553999
다음은 log4j 공식 API 에서 쓴 것 으로 logger 와 category 의 차 이 를 설명 할 수 있 습 니 다.

public class Category
     
     
     
     

extends java.lang.Object
implements
AppenderAttachable
This class has been deprecated and replaced by the Logger subclass. It will be kept around to preserve backward compatibility until mid 2003. Logger is a subclass of Category, i.e. it extends Category. In other words, a loggeris a category. Thus, all operations that can be performed on a category can be performed on a logger. Internally, whenever log4j is asked to produce a Category object, it will instead produce a Logger object. Log4j 1.2 willnever produce Category objects but only Logger instances. In order to preserve backward compatibility, methods that previously accepted category objects still continue to accept category objects.
For example, the following are all legal and will work as expected.

       // Deprecated form:
       Category cat = Category.getInstance("foo.bar")

       // Preferred form for retrieving loggers:
       Logger logger = Logger.getLogger("foo.bar")
   

The first form is deprecated and should be avoided.
There is absolutely no need for new client code to use or refer to the Category class. Whenever possible, please avoid referring to it or using it.
See the short manual for an introduction on this class.
See the document entitled preparing for log4j 1.3 for a more detailed discussion.
Author:
Ceki Gülcü, Anders Kristensen
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