java - Intellij 严重 tomcat 错误 : failing to start component

Question

我在尝试将 Web 部署到本地主机时遇到 Intellij 的奇怪问题。

各种搜索推断问题是由于与java版本不一致，但我看不出是怎么回事。

我有一个工作站点，siteA。损坏的站点 siteB “几乎”是 siteA 的副本，尤其是在涉及 spring 配置等方面。这样做的真正原因是我不擅长配置并且更喜欢处理“有趣”的东西。这似乎是我的垮台。

但是，我已经比较了两个项目的部署选项，它们是相同的，poms/versions/xml 等也是如此。名称已更改以反射(reflect)不同的项目，但最终它们'重新使用相同的设置。

然后我从 siteA 导出了所有 intelliJ 设置并将这些设置导入到 siteB - 仍然是同样的错误。

有人可以解释一下吗？

提前致谢!

编辑:我已经为 servlet-api 添加了 provided 到 pom，这样错误消息就不再存在了。错误:

 SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]`

完整的堆栈跟踪:

    /Library/Tomcat/bin/catalina.sh run
[2015-09-05 11:00:57,845] Artifact RatedPlate:war exploded: Server is not connected. Deploy is not available.
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log

INFO: Server version:        Apache Tomcat/7.0.61
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Mar 27 2015 12:03:56 UTC
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         7.0.61.0
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Mac OS X
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.10.5
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          x86_64
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.8.0_45-b14
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         /Users/SteveGreen/Library/Caches/IntelliJIdea14/tomcat/Unnamed_RatedPlate_2
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         /Library/Tomcat
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.config.file=/Users/SteveGreen/Library/Caches/IntelliJIdea14/tomcat/Unnamed_RatedPlate_2/conf/logging.properties
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote=
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.port=2099
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.ssl=false
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.authenticate=false
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.rmi.server.hostname=127.0.0.1
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=/Library/Tomcat/endorsed
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=/Users/SteveGreen/Library/Caches/IntelliJIdea14/tomcat/Unnamed_RatedPlate_2
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=/Library/Tomcat
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.io.tmpdir=/Library/Tomcat/temp
Sep 05, 2015 11:00:58 AM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /Users/SteveGreen/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
Sep 05, 2015 11:00:58 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8081"]
Sep 05, 2015 11:00:58 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 573 ms
Sep 05, 2015 11:00:58 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Sep 05, 2015 11:00:58 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.61
Sep 05, 2015 11:00:58 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8081"]
Sep 05, 2015 11:00:58 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
Sep 05, 2015 11:00:58 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 56 ms
Connected to server
[2015-09-05 11:00:58,731] Artifact RatedPlate:war exploded: Artifact is being deployed, please wait...
Sep 05, 2015 11:00:58 AM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/Users/SteveGreen/Development/Dev Workspace/RatedPlate_Java/RatedPlate/target/ratedplate-1.0-SNAPSHOT/WEB-INF/lib/servlet-api-2.5.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
Sep 05, 2015 11:00:59 AM org.apache.catalina.core.StandardContext checkUnusualURLPattern
INFO: Suspicious url pattern: "/pdfs/**" in context [] - see sections 12.1 and 12.2 of the Servlet specification
Sep 05, 2015 11:00:59 AM org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    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:652)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1779)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1466)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1307)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1399)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:828)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$254(TCPTransport.java:683)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$1/306620140.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    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)
Caused by: java.lang.IllegalArgumentException: Servlet mapping specifies an unknown servlet name Devolution
    at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3320)
    at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3299)
    at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1438)
    at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1357)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
    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:5416)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 43 more

Sep 05, 2015 11:00:59 AM org.apache.tomcat.util.modeler.BaseModelMBean invoke
SEVERE: Exception invoking method manageApp
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:904)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1779)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1466)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1307)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1399)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:828)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$254(TCPTransport.java:683)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$1/306620140.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    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)

Sep 05, 2015 11:00:59 AM org.apache.tomcat.util.modeler.BaseModelMBean invoke
SEVERE: Exception invoking method createStandardContext
javax.management.RuntimeOperationsException: Exception invoking method manageApp
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:309)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1466)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1307)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1399)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:828)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$254(TCPTransport.java:683)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$1/306620140.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    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)
Caused by: java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:904)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1779)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    ... 34 more

[2015-09-05 11:00:59,544] Artifact RatedPlate:war exploded: Error during artifact deployment. See server log for details.
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /Library/Tomcat/webapps/docs
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /Library/Tomcat/webapps/docs has finished in 62 ms
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /Library/Tomcat/webapps/examples
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /Library/Tomcat/webapps/examples has finished in 110 ms
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /Library/Tomcat/webapps/host-manager
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /Library/Tomcat/webapps/host-manager has finished in 23 ms
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /Library/Tomcat/webapps/manager
Sep 05, 2015 11:01:08 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /Library/Tomcat/webapps/manager has finished in 25 ms

Answer 1

查看堆栈跟踪中的行:

Caused by: java.lang.IllegalArgumentException: Servlet mapping specifies an unknown servlet name Devolution

错误是由您的 xml 文件中名为 Devolution 的 servlet 引起的。