Eclipse tomcat8服务器启动失败错误

Eclipse tomcat8服务器启动失败错误,eclipse,tomcat,Eclipse,Tomcat,我是TomcatApache服务器的新手,我正在尝试编译我的一个web项目。由于某些原因,当我尝试运行tomcat服务器时,出现以下错误: Server Tomcat v8.0 Server at localhost failed to start. 从错误中我不明白问题出在哪里 这是我的输出控制台: Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.digester.SetPropertiesRule begin WARNING: [SetPr

我是TomcatApache服务器的新手,我正在尝试编译我的一个web项目。由于某些原因,当我尝试运行tomcat服务器时,出现以下错误:

Server Tomcat v8.0 Server at localhost failed to start.
从错误中我不明白问题出在哪里

这是我的输出控制台:

 Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:myfirstjsp' did not find a matching property.
Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:RestApi' did not find a matching property.
Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.j2ee.server:springexample' did not find a matching property.
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version:        Apache Tomcat/8.0.30
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Dec 1 2015 22:30:46 UTC
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         8.0.30.0
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Linux
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            3.19.0-49-generic
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             /usr/lib/jvm/java-7-openjdk-amd64/jre
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.7.0_95-b00
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         /home/matant/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         /home/matant/apache-tomcat-8.0.30
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=/home/matant/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=/home/matant/apache-tomcat-8.0.30
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=/home/matant/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=/home/matant/apache-tomcat-8.0.30/endorsed
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=UTF-8
Feb 11, 2016 12:08:42 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: /usr/java/packages/lib/amd64:/usr/lib/x86_64-linux-gnu/jni:/lib/x86_64-linux-gnu:/usr/lib/x86_64-linux-gnu:/usr/lib/jni:/lib:/usr/lib
Feb 11, 2016 12:08:42 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
Feb 11, 2016 12:08:42 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-nio-8009"]
Feb 11, 2016 12:08:42 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
Feb 11, 2016 12:08:42 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 2575 ms
Feb 11, 2016 12:08:43 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Feb 11, 2016 12:08:43 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/8.0.30
Feb 11, 2016 12:08:46 AM 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[/RestApi]]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:188)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    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:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/RestApi]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    ... 6 more
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Class.java:2509)
    at java.lang.Class.getDeclaredFields(Class.java:1819)
    at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
    at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:256)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:132)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
    at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:334)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:774)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:305)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:95)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5154)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
    ... 20 more

Feb 11, 2016 12:08:47 AM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 11, 2016 12:08:49 AM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 11, 2016 12:08:49 AM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
Feb 11, 2016 12:08:49 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'mvc-dispatcher'
Feb 11, 2016 12:08:49 AM org.springframework.web.servlet.DispatcherServlet initServletBean
INFO: FrameworkServlet 'mvc-dispatcher': initialization started
Feb 11, 2016 12:08:49 AM org.springframework.web.context.support.XmlWebApplicationContext prepareRefresh
INFO: Refreshing WebApplicationContext for namespace 'mvc-dispatcher-servlet': startup date [Thu Feb 11 00:08:49 PST 2016]; root of context hierarchy
Feb 11, 2016 12:08:50 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from ServletContext resource [/WEB-INF/mvc-dispatcher-servlet.xml]
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/hello] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/hello.*] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/hello/] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/displayMessage/{msg}] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/displayMessage/{msg}.*] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/displayMessage/{msg}/] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/knainz] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/knainz.*] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/knainz/] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/func1] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/func1.*] onto handler 'helloWorldController'
Feb 11, 2016 12:08:51 AM org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping registerHandler
INFO: Mapped URL path [/helloWorld/func1/] onto handler 'helloWorldController'
Feb 11, 2016 12:08:52 AM org.springframework.web.servlet.DispatcherServlet initServletBean
INFO: FrameworkServlet 'mvc-dispatcher': initialization completed in 2896 ms
Feb 11, 2016 12:08:52 AM 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(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:188)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:441)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:769)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:625)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
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$StartChild.call(ContainerBase.java:1408)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    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:745)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:924)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more

Feb 11, 2016 12:08:52 AM 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:625)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
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:769)
    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:441)
    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:924)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 11 more

Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["http-nio-8080"]
Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["ajp-nio-8009"]
Feb 11, 2016 12:08:52 AM org.apache.catalina.core.StandardService stopInternal
INFO: Stopping service Catalina
Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["http-nio-8080"]
Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol destroy
SEVERE: Failed to destroy end point associated with ProtocolHandler ["http-nio-8080"]
java.lang.NullPointerException
    at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:305)
    at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:481)
    at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:823)
    at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:533)
    at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:859)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:629)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)

Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["ajp-nio-8009"]
Feb 11, 2016 12:08:52 AM org.apache.coyote.AbstractProtocol destroy
SEVERE: Failed to destroy end point associated with ProtocolHandler ["ajp-nio-8009"]
java.lang.NullPointerException
    at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:305)
    at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:481)
    at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:823)
    at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:533)
    at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:859)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:629)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)

Feb 11, 2016 12:08:52 AM org.apache.catalina.core.ApplicationContext log
INFO: Destroying Spring FrameworkServlet 'mvc-dispatcher'
Feb 11, 2016 12:08:52 AM org.springframework.web.context.support.XmlWebApplicationContext doClose
INFO: Closing WebApplicationContext for namespace 'mvc-dispatcher-servlet': startup date [Thu Feb 11 00:08:49 PST 2016]; root of context hierarchy

错误似乎是由以下原因引起的:

java.lang.ClassNotFoundException: org.apache.commons.logging.Log

您似乎忘记在应用程序项目中包含Commons日志JAR。

错误似乎是由以下原因造成的:

java.lang.ClassNotFoundException: org.apache.commons.logging.Log

您似乎忘记了在应用程序项目中包含Commons日志JAR。

如果您还没有解决这个问题,请按照以下步骤操作

我的win7帐户名是JHTA

C:\Users\JHTA.m2\repository

删除所有文件并重新启动eclipse或STS

并等待下载构建过程


修好它

如果您还没有修复该问题,请按照以下步骤操作

我的win7帐户名是JHTA

C:\Users\JHTA.m2\repository

删除所有文件并重新启动eclipse或STS

并等待下载构建过程


修好它

你知道我该如何修复它吗?看看你的webcontent->WEB-INF/lib文件夹中是否有JAR。如果没有,请从下载您知道如何修复它吗?查看您的webcontent->WEB-INF/lib文件夹中是否有JAR。如果没有,请从