我在使用log4j时遇到了以下错误。任何人都可以猜出可能是什么问题？ 提前致谢
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 [sun.misc.Launcher$AppClassLoader@43540a77] whereas object of type
log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by [WebAppClassLoader].
log4j:ERROR Could not instantiate appender named "stdout".
这些是用log4j.properties文件
编写的行log4j.rootLogger=error, stdout
log4j.logger.java.sql=error
log4j.logger.com.example.test=error
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{DATE} %5p %c{1}:%L - %m%n