错误无法实例化类 [org.apache.log4j.rolling.RollingFileAppender]答案

【问题标题】：ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender]错误无法实例化类 [org.apache.log4j.rolling.RollingFileAppender]
【发布时间】：2018-07-06 10:19:34
【问题描述】：

我正在使用 log4j-1.2.17.jar 和 apache-log4j-extras-1.2.17.jar。

我想启用滚动文件，但是当我尝试启动服务器时出现错误..

My log4j.properties file looks like this.

log4j.appender.LOG_CRON_SIJ=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.LOG_CRON_SIJ.append=true
log4j.appender.LOG_CRON_SIJ.encoding=UTF-8
log4j.appender.LOG_CRON_SIJ.rollingPolicy=org.apache.log4j.rolling.TimeBasedRollingPolicy
log4j.appender.LOG_CRON_SIJ.rollingPolicy.FileNamePattern=${rootLog}/agendaNojCRONSIJ_%d{dd-MM-yyyy HH-mm-ss}.log
log4j.appender.LOG_CRON_SIJ.rollingPolicy.activeFileName=${rootLog}/agendaNojCRONSIJ.log
log4j.appender.LOG_CRON_SIJ.triggeringPolicy=org.apache.log4j.rolling.SizeBasedTriggeringPolicy
log4j.appender.LOG_CRON_SIJ.triggeringPolicy.maxFileSize=52428800
log4j.appender.LOG_CRON_SIJ.layout=org.apache.log4j.EnhancedPatternLayout
log4j.appender.LOG_CRON_SIJ.layout.ConversionPattern=%d %-5p %c - %m%n

错误：

   log4j:ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender].
java.lang.ClassNotFoundException: org.apache.log4j.rolling.RollingFileAppender
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:171)
    at org.apache.log4j.helpers.Loader.loadClass(Loader.java:198)
    at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:327)
    at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:124)
    at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:785)
    ...
    ...
    ...
log4j:ERROR Could not instantiate appender named "LOG_CRON_SIJ".
log4j:ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender].
java.lang.ClassNotFoundException: org.apache.log4j.rolling.RollingFileAppender
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:171)
    at org.apache.log4j.helpers.Loader.loadClass(Loader.java:198)
    at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:327)
    at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:124)
    ....
    ....

log4j:WARN Failed to set property [triggeringPolicy] to value "org.apache.log4j.rolling.SizeBasedTriggeringPolicy". 
log4j:WARN Failed to set property [rollingPolicy] to value "org.apache.log4j.rolling.TimeBasedRollingPolicy". 
log4j:WARN Please set a rolling policy for the RollingFileAppender named 'LOG_CRON_SIJ'

谁能帮帮我？？？

【问题讨论】：

看来你在运行时没有apache-log4j-extras-1.2.17，你是如何添加依赖项的？

标签： java log4j

【解决方案1】：

请检查您的类路径中是否有RollingFileAppender (Apache Log4j 1.2.17 API) 所需的依赖项。如果在您的类路径中未找到任何实际在某处实例化的类，您将遇到此类错误。所以请检查日志依赖。

【讨论】：