【发布时间】：2014-10-08 08:13:15
【问题描述】：
我在 Tomcat 8.0.12 中运行的 servlet 3.0 Web 应用程序中使用 log4j2 (2.0.2)。我正在尝试使用 weblookup 来获取 Web 应用程序上下文路径以用作日志文件名的一部分。 （我们使用属性在几个不同的上下文中运行相同的war文件来配置它）。
log4j2.xml 文件包括
<RollingFile name="Web" fileName="/srv/dnsnet/logs/web-${web:contextPath}.logfile" filePattern="/srv/dnsnet/logs/web-${web:contextPath}-%d{yyyy-MM-dd}-%i.log.gz" append="true" immediateFlush="false">
<PatternLayout>
<Pattern>%d %-5p [%25.25t] %40.40c{3.} %15X{sysid} %m%n</Pattern>
</PatternLayout>
<Policies>
<TimeBasedTriggeringPolicy />
</Policies>
<DefaultRolloverStrategy max="8"/>
</RollingFile>
但是 web:contextPath 没有得到解决。我的网络应用程序中有 log4j-web-2.0.2.jar。我在WebLookup类中添加了一些消息，问题是LoggerContext的外部上下文为null。
所以我试图查看 LoggerContext 的创建位置。调用 LoggerContext 构造函数时的堆栈跟踪是
at org.apache.logging.log4j.core.LoggerContext.<init>(LoggerContext.java:114)
at org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.locateContext(ClassLoaderContextSelector.java:218)
at org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.getContext(ClassLoaderContextSelector.java:113)
at org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.getContext(ClassLoaderContextSelector.java:80)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:82)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:37)
at org.apache.logging.log4j.LogManager.getContext(LogManager.java:269)
at org.apache.logging.log4j.jcl.LogFactoryImpl$PrivateManager.getContext(LogFactoryImpl.java:108)
at org.apache.logging.log4j.jcl.LogFactoryImpl.getLoggersMap(LogFactoryImpl.java:52)
at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:43)
at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:75)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
at org.apache.myfaces.webapp.AbstractMyFacesListener.<clinit>(AbstractMyFacesListener.java:34)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
at java.lang.Class.newInstance(Class.java:433)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:151)
at org.apache.catalina.core.ApplicationContext.addListener(ApplicationContext.java:1231)
at org.apache.catalina.core.ApplicationContextFacade.addListener(ApplicationContextFacade.java:647)
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:110)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5164)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:581)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1686)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745
但是 ClassLoaderContextSelector 总是为外部上下文传递 null。所以看起来我好像错过了什么。
谁能建议我做错了什么或遗漏了什么？我必须指定不同的 ContextSelector 吗？
【问题讨论】：