Solution: log4j:warn please initialize the log4j system properly

background ：
springboot+maven+mybatis project , An error is as follows ：

resolvent ：
stay resources New file in directory log4j.properties, Add the following code ：

log4j.rootLogger=WARN, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n

The relevant screenshots are as follows ：

Link to the original text ：https://blog.csdn.net/lezeqe/article/details/103805338