slf4j 版本与 Tomcat 和 WebApplicationInitializer 不匹配答案

【问题标题】：Mismatch slf4j version with Tomcat and WebApplicationInitializerslf4j 版本与 Tomcat 和 WebApplicationInitializer 不匹配
【发布时间】：2013-09-04 16:06:41
【问题描述】：

当我尝试在 Tomcat 上部署我的应用程序时出现以下错误。

04-Sep-2013 17:59:29.424 SEVERE [AsyncFileHandlerWriter-1626573634] org.apache.catalina.core.StandardContext.startInternal Error during ServletContainerInitializer processing
 javax.servlet.ServletException: Failed to instantiate WebApplicationInitializer class
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:165)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5370)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:977)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1655)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.LinkageError: loader constraint violation: when resolving method "org.slf4j.impl.StaticLoggerBinder.getLoggerFactory()Lorg/slf4j/ILoggerFactory;" the class loader (instance of org/springframework/instrument/classloading/tomcat/TomcatInstrumentableClassLoader) of the current class, org/slf4j/LoggerFactory, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/slf4j/impl/StaticLoggerBinder, have different Class objects for the type LoggerFactory; used in the signature
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:299)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:269)
    at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:156)
    at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:132)
    at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
    at org.springframework.web.context.AbstractContextLoaderInitializer.<init>(AbstractContextLoaderInitializer.java:42)
    at org.springframework.web.servlet.support.AbstractDispatcherServletInitializer.<init>(AbstractDispatcherServletInitializer.java:58)
    at org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer.<init>(AbstractAnnotationConfigDispatcherServletInitializer.java:40)
    at com.bravofly.wfcobrand.configuration.web.ServletConfiguration.<init>(ServletConfiguration.java:10)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at java.lang.Class.newInstance(Class.java:374)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:162)
    ... 13 more

我已经发现问题出在 lib 目录中的库中：slf4j-api-1.5.11.jar。

将org.slf4j:slf4j-api:1.7.1 和org.slf4j:jcl-over-slf4j:1.7.1 放入其中解决了我的问题。

我想知道是否可以在我的应用中做一些事情来解决这个问题。我正在使用 gradle，所以我放了：

  compile ... other dependencies
          "org.slf4j:slf4j-api:1.7.1",
          "org.slf4j:jcl-over-slf4j:1.7.1"

但这并没有解决问题。有没有办法优先考虑我的构建文件中定义的库？

【问题讨论】：

PS：我知道 Tomcat 会优先考虑我的 webapp 中的库来加载它们，但是我遇到了同样的错误，所以我猜当涉及到不同版本的同一个库

标签： java spring tomcat7 gradle slf4j

【解决方案1】：

虽然我仍然不确定为什么，但共享 lib 目录中的 servlet 容器是另一个项目的旧版本。因此，当我们删除它时，一切正常。

我们使用的是 Tomcat 7，我相信应用程序库具有优先权，但显然如果它的某个版本已经加载，它就会丢弃我们的。

【讨论】：