在使用httpclient时报错，org.apache.http.ssl.SSLContexts找不到

Question

今天下午测试时，使用httpclient调用子系统服务时，报错org.apache.http.ssl.SSLContexts找不到。tomcat启动没报错，就是再调用service时，我的service实现类里调用了httpclient的API，
从日志里看貌似时这句话里面错了CloseableHttpClient httpclient = HttpClients.createDefault();httpclient4.5.1.jar和httpcore4.4.3.jar在maven里都引入了，网上说换高版本的也都换了，还是不行。并且这个类在httpcore.jar包里也能找到。看到这里报了两个错NoClassDefFoundError和ClassNotFoundException。后两句标红的内容是说明tomcat也出错了吗？求解决问题，谢了具体错误信息：
严重: Servlet.service() for servlet [jayo-portal] in context with path [] threw exception [Handler dispatch failed; nested exception is java.lang.NoClassDefFoundError: org/apache/http/ssl/SSLContexts] with root cause
java.lang.ClassNotFoundException: org.apache.http.ssl.SSLContexts
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:966)
at org.apache.http.impl.client.HttpClients.createDefault(HttpClients.java:58)
at com.jayo.common.utils.HttpClientUtil.doGet(HttpClientUtil.java:27)
at com.jayo.common.utils.HttpClientUtil.doGet(HttpClientUtil.java:66)
at com.jayo.portal.service.impl.ContentServiceImpl.getContentList(ContentServiceImpl.java:29)
at com.jayo.portal.controller.IndexController.showIndex(IndexController.java:18)
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:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
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)

Answer 1

资源找不到要么是真的没有这个资源，要么是资源多了重复，冲突了，估计你是jar重复了

Answer 2

不会吧，maven引入的jar包我看了，确实只有一个。你的意思是多个jar包同时依赖了某个jar，造成版本冲突？

Answer 3

问题解决了，原因是什么我还不清楚，最后我把仓库里的httpclient相关的JAR包删了，又让eclipse重新下了一遍就行了