1.遇到问题 log4j:WARN No appenders could be found for logger (com.mvn.spring.Tt). log4j:WARN Please initialize the log4j system properly. log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noc
# Set root logger level to WARN and append to stdoutlog4j.rootLogger=WARN, stdout, error#WARN为log输出级别，stdout，error为该log的别名，下面将用到log4j.appender.stdout=...
