Question

获取此依赖项的问题，尽管它未在我的pom.xml中显式引用为依赖项。实际的maven依赖是：

  <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.2.5</version>
    </dependency>

我的控制台的堆栈跟踪是：

 java.lang.NoClassDefFoundError: org/apache/http/impl/conn/PoolingClientConnectionManager
at com.gbi.gsa.Bridge.createClient(Bridge.java:50)
at com.gbi.gsa.Bridge.<init>(Bridge.java:46)
at com.gbi.gsa.SimpleBridge.<init>(SimpleBridge.java:34)
at   com.gbi.quickstart.controller.NavigationController.handleRequestInternal(NavigationController.java:114)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:755)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:669)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1336)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1307)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:453)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:560)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1072)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:382)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1006)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:255)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:154)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:365)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:485)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:937)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:998)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:856)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:240)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:628)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.ClassNotFoundException:   org.apache.http.impl.conn.PoolingClientConnectionManager
at   org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:430)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:383)
... 41 more

我尝试删除我的.m2 / repositories目录并下载我的依赖项（通过maven）但它仍然无法正常工作。

Answer 1

您的问题可能与依赖项无关。 NoClassDefFoundError与ClassNotFoundException不同。这意味着该类在编译时可用，但无法初始化，通常是由于静态块中的异常。这个答案有好油。 What causes and what are the differences between NoClassDefFoundError and ClassNotFoundException?

Answer 2

尝试将httpClient版本从4.2.5更改为4.3.4 ......这对我有用......

Answer 3

因为它适用于我，请发布您的原始pom。同时检查您是否在代理服务器后面，并且您的.m2 /设置有效。

Answer 4

请检查您在项目中使用的servlet-api的版本，以及Spring-web，httclient等第三方jar的poms。如果使用servlet版本3.0.1和httpclient编译spring jar或者它的依赖项是用servlet 2.5.6编译的，那么可能会出现这个问题。

在升级项目的某些第三方依赖项时，我遇到了类似的问题。

java.lang.NoClassDefFoundError：org / apache / http / impl / conn / PoolingClientConnectionManager

4 个答案: