请教log4j如何将不同的级别输入不同的文件

目前我希望将log4j的日志内容按照其不同的级别输出到不同的日志文件中，在google和自己摸索后没有成功，具体配置文件如下

log4j.threshold=DEBUG
log4j.rootLogger= debug, stdout, DebugAppender, InfoAppender, WarnAppender, ErrorAppender

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%c %d{ISO8601} -- %p -- %m%n

log4j.logger.DebugAppender.access=DEBUG
log4j.appender.DebugAppender=org.apache.log4j.RollingFileAppender
log4j.appender.DebugAppender.File=F:/workspace/test/logs/app-debug.log
log4j.appender.DebugAppender.MaxFileSize=500KB
log4j.appender.DebugAppender.MaxBackupIndex=10
log4j.appender.DebugAppender.threshold = DEBUG
log4j.appender.DebugAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.DebugAppender.layout.ConversionPattern=%c %d{ISO8601} -- %p -- %m%n

log4j.logger.InfoAppender.access=INFO
log4j.appender.InfoAppender=org.apache.log4j.RollingFileAppender
log4j.appender.InfoAppender.File=F:/workspace/test/logs/app-info.log
log4j.appender.InfoAppender.MaxFileSize=500KB
log4j.appender.InfoAppender.MaxBackupIndex=10
log4j.appender.InfoAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.InfoAppender.threshold = INFO
log4j.appender.InfoAppender.layout.ConversionPattern=%c %d{ISO8601} -- %p -- %m%n

log4j.logger.WarnAppender.access=WARN
log4j.appender.WarnAppender=org.apache.log4j.RollingFileAppender
log4j.appender.WarnAppender.File=F:/workspace/test/logs/app-warn.log
log4j.appender.WarnAppender.MaxFileSize=500KB
log4j.appender.WarnAppender.MaxBackupIndex=10
log4j.appender.WarnAppender.threshold = WARN
log4j.appender.WarnAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.WarnAppender.layout.ConversionPattern=%c %d{ISO8601} -- %p -- %m%n

log4j.logger.ErrorAppender.access=ERROR
log4j.appender.ErrorAppender=org.apache.log4j.RollingFileAppender
log4j.appender.ErrorAppender.File=F:/workspace/test/logs/app-error.log
log4j.appender.ErrorAppender.MaxFileSize=500KB
log4j.appender.ErrorAppender.MaxBackupIndex=10
log4j.appender.ErrorAppender.threshold = ERROR
log4j.appender.ErrorAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.ErrorAppender.layout.ConversionPattern=%c %d{ISO8601} -- %p -- %m%n

目前的效果是文件都能够生成，但是每个文件内日志的级别都全部输出，并没有只输出我指定的级别。希望各位能够指点一下：）