在运行一个简单的Struts 2应用程序时遇到错误我正在使用Struts 2.5.10.1

Question

This is content of my Error blog

    May 01, 2017 1:40:03 PM org.apache.catalina.core.AprLifecycleListener init
    INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre1.8.0_102\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre1.8.0_102/bin/server;C:/Program Files/Java/jre1.8.0_102/bin;C:/Program Files/Java/jre1.8.0_102/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\java\eclipse-jee-juno-SR2-win32-x86_64;;.
    May 01, 2017 1:40:03 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
    WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:StrutsTrial' did not find a matching property.
    May 01, 2017 1:40:03 PM org.apache.coyote.AbstractProtocol init
    INFO: Initializing ProtocolHandler ["http-bio-8080"]
    May 01, 2017 1:40:03 PM org.apache.coyote.AbstractProtocol init
    INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
    May 01, 2017 1:40:03 PM org.apache.catalina.startup.Catalina load
    INFO: Initialization processed in 861 ms
    May 01, 2017 1:40:03 PM org.apache.catalina.core.StandardService startInternal
    INFO: Starting service Catalina
    May 01, 2017 1:40:03 PM org.apache.catalina.core.StandardEngine startInternal
    INFO: Starting Servlet Engine: Apache Tomcat/7.0.56
    May 01, 2017 1:40:04 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
    INFO: validateJarFile(D:\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\StrutsTrial\WEB-INF\lib\servlet-api.jar)
- jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
    May 01, 2017 1:40:05 PM org.apache.catalina.core.ContainerBase startInternal
    SEVERE: A child container failed during start
    java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/StrutsTrial]]
        at java.util.concurrent.FutureTask.report(Unknown Source)
        at java.util.concurrent.FutureTask.get(Unknown Source)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:816)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
    Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/StrutsTrial]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        ... 6 more
    Caused by: java.lang.NoClassDefFoundError: Lorg/apache/logging/log4j/Logger;
        at java.lang.Class.getDeclaredFields0(Native Method)
        at java.lang.Class.privateGetDeclaredFields(Unknown Source)
        at java.lang.Class.getDeclaredFields(Unknown Source)
        at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
        at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:270)
        at org.apache.catalina.startup.WebAnnotationSet.loadApplicationFilterAnnotations(WebAnnotationSet.java:109)
        at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:64)
        at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:415)
        at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:892)
        at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
        at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5380)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 6 more
    Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
        ... 20 more

    May 01, 2017 1:40:05 PM org.apache.catalina.core.ContainerBase startInternal
    SEVERE: A child container failed during start
    java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
        at java.util.concurrent.FutureTask.report(Unknown Source)
        at java.util.concurrent.FutureTask.get(Unknown Source)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
    Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
    Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:816)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 6 more

    May 01, 2017 1:40:05 PM org.apache.catalina.startup.Catalina start
    SEVERE: The required Server component failed to start so Tomcat is unable to start.
    org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
    Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 7 more
    Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 9 more
    Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 11 more

It is also showing a dialogbox that contains:

"Starting tomcat v7.0 Server at localhost has encountered a problem.Server Tomcat v7.0 Server at localhost failed to start."

This is My web.xml file

> <?xml version="1.0" encoding="UTF-8"?> <web-app
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xmlns="http://java.sun.com/xml/ns/javaee"
> xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
> xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
> http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID"
> version="2.5">   <display-name>StrutsTrial</display-name>  
> <welcome-file-list>
>     <welcome-file>form1.html</welcome-file>   </welcome-file-list>   <filter>   <filter-name>struts2</filter-name>   <filter-class>
> org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
> </filter> <filter-mapping> <filter-name>struts2</filter-name>
> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>

Answer 1

The class is missing org.apache.logging.log4j.Logger

to fix the issue add Maven dependency to your project

  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.4.1</version>
  </dependency>