The freemarker dependency package is introduced into the project. However, the red warning caused by the corresponding log level is not configured in the log4j.properties file. as follows:

< dependency >
   < groupId > org.springframework.boot </ groupId >
   < artifactId > spring-boot-starter-freemarker </ artifactId >
</ dependency >

log4j :WARN No appenders could be found for logger (freemarker.cache).
log4j :WARN Please initialize the log4j system properly.
log4j : WARN See HTTP : //logging.apache.org/log4j/1.2/faq.html#noconfig for More info.

Solution: log4j.properties plus the corresponding configuration

log4j.logger.freemarker.cache =ERROR
log4j.logger.freemarker.beans =ERROR