严重：servlet jsp 的 Servlet.service() 引发异常 java.lang.LinkageError：加载程序约束违规 [重复]答案

【问题标题】：SEVERE: Servlet.service() for servlet jsp threw exception java.lang.LinkageError: loader constraint violation [duplicate]严重：servlet jsp 的 Servlet.service() 引发异常 java.lang.LinkageError：加载程序约束违规 [重复]
【发布时间】：2013-09-25 01:04:10
【问题描述】：

我正在使用 Spring 并尝试使用 tomcat 7 启动应用程序，但我不断收到此错误，并且在与 Spring 相关的 Linkeage 错误上找不到太多信息。

这是完整的错误：

Sep 24, 2013 7:54:15 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.LinkageError: loader constraint violation: when resolving interface method "javax.servlet.jsp.JspApplicationContext.getExpressionFactory()Ljavax/el/ExpressionFactory;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/WEB_002dINF/views/home_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, javax/servlet/jsp/JspApplicationContext, have different Class objects for the type avax/el/ExpressionFactory; used in the signature
    at org.apache.jsp.WEB_002dINF.views.home_jsp._jspInit(home_jsp.java:23)
    at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:171)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
    at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
    at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:262)
    at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1180)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:950)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)

【问题讨论】：

在我看来，您的类路径中有两个 jsp-api.jars。你用的是maven吗？如果是这样，请发布您的 pom.xml。否则，请在WEB-INF/lib 中发布您的内容。

标签： java spring jsp servlets spring-mvc

【解决方案1】：

我在 tomcat 6.0 上部署应用时遇到了同样的错误

我在发行说明中发现 el-api JAR 文件已默认包含在内。 Tomcat 正在尝试加载它不喜欢的两个不同的 JAR。

删除 WEB-INF/lib 文件夹中的 el-api JAR，然后重试。

【讨论】：

【解决方案2】：

在尝试 Spring roo 应用程序时遇到了同样的错误。感谢 user1724646，通过注释掉 pom.xml 中的 el-api.jar 解决了这个问题

 <!--<dependency>
        <groupId>javax.el</groupId>
        <artifactId>el-api</artifactId>
        <version>2.2</version>
        <scope>provided</scope>
 </dependency> -->

【讨论】：

【解决方案3】：

这个问题是由两个版本的el-api 加载引起的。默认情况下，Tomcat 7 Common 类加载器加载 el-api 2.2 更多信息可以在 http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html 上找到。这个类加载器加载的 jars 位于$CATALINA_HOME/lib。解决方案是从您的 Web 应用程序中删除 el-api jar（即WEB-INF/lib）。

【讨论】：