log4j 突然不打印记录，提示：No appenders could be found for logge，处理方法

log4j 一直都在使用正常，log4j.xml配置、代码都没有修改，突然不打印记录，出现下面提示：

log4j:WARN No appenders could be found for logger (com.fc.htgl.testcases.TestOrderPrice).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

处理方法：eclipse  project >clean