項目用tomcat啓動時，控制檯報如下錯誤，雖然不影響業務正常使用，但還是要把它解決。
"org.apache.log4j.ConsoleAppender" object is not assignable to a "org.apache.log4j.Appender" variable
Could not instantiate appender named "Console".
log4j:ERROR A "org.apache.log4j.ConsoleAppender" object is not assignable to a "org.apache.log4j.Appender" variable.
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
log4j:ERROR [org.apache.catalina.loader.StandardClassLoader@1175e2db] whereas object of type
log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by [WebappClassLoader
context: /ifs_core
delegate: false
repositories:
/WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@1175e2db
].
log4j:ERROR Could not instantiate appender named "Console".
log4j:ERROR A "org.apache.log4j.DailyRollingFileAppender" object is not assignable to a "org.apache.log4j.Appender" variable.
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
log4j:ERROR [org.apache.catalina.loader.StandardClassLoader@1175e2db] whereas object of type
log4j:ERROR "org.apache.log4j.DailyRollingFileAppender" was loaded by [WebappClassLoader
context: /ifs_core
delegate: false
repositories:
/WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@1175e2db
].
log4j:ERROR Could not instantiate appender named "R".
log4j:ERROR A "org.apache.log4j.DailyRollingFileAppender" object is not assignable to a "org.apache.log4j.Appender" variable.
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
log4j:ERROR [org.apache.catalina.loader.StandardClassLoader@1175e2db] whereas object of type
log4j:ERROR "org.apache.log4j.DailyRollingFileAppender" was loaded by [WebappClassLoader
context: /ifs_core
delegate: false
repositories:
/WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@1175e2db
解決方法：
這種情況多半的jar包衝突導致，發現項目中有log4j-1.2.16.jar，也有log4j-2.3.jar，排除log4j-1.2.16.jar後問題解決。
在此安利下IDEA插件Maven Helper，解決jar包衝突相當方便。
