java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0

java.lang.reflect.InvocationTargetException
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 cmcc.gz.platform.app.utils.AppSIUtil.executeAppMethod(AppSIUtil.java:686)
at cmcc.gz.platform.app.web.controller.CommonAppSiDefineController.executeAppV3SI(CommonAppSiDefineController.java:259)
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.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at cmcc.gz.platform.core.web.filter.PermissionChecksFilter.doFilter(PermissionChecksFilter.java:114)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
at cmcc.gz.interfaces.service.IClientAppQuestionnaireService.queryQuestionnaire(IClientAppQuestionnaireService.java:32)

... 51 more

今天调试接口的时候遇到这个 反射的异常, 在网上百度了一下 ,有的人说是jar包的问题,有的说是代码的问题,首先我先说说我的问题:    我编写了一个 普通的接口  我使用controller调用的时候 没有任何问题 但是在客户端调用我的接口的时候却出现了问题,首先  我是获取 客户端 用户的信息, 而这些信息都被封装 到了一个类的里面 

public Map queryQuestionnaire(AppUserBean userBean, Map parameter){
    Map resultMap = new HashMap();
    String floworbill = parameter.get("floworbill").toString();

客户端调用的时候出现 了  他们传递了 

String floworbill = parameter.get("floworbill").toString();

floworbill  这个值 但是后台一直拿不到 一直为 null  但是使用其中的某一个参数的话都是可行的  后来使用项目的调试工具  还是报反射异常,  

那么问题来了, 客户端他们传递数据,项目配置的时候 都是按照反射的原理来的,既然上面说了  单独测试的时候 也就是 传其中的某一个参数的时候 都是没问题的  那参数肯定是没问题的

原因: 

public Map queryQuestionnaire(Map parameter, AppUserBean userBean){
    Map resultMap = new HashMap();
    String floworbill = parameter.get("floworbill").toString();

   把两个参数对调下位置就可以成功了

因为是用了反射的原理,所以有很多的接口 那程序是怎么知道你到底是调用了哪一个接口呢, 我个人认为 它应该是使用了重载的原理 ,它是根据你的参数来进行判断的 ,  可能这样的参数形式它们都已经实现了重载  :

public Map queryQuestionnaire(Map parameter, AppUserBean userBean){

public Map queryQuestionnaire(Map parameter){

public Map queryQuestionnaire(AppUserBean userBean){

下面的额是没有实现重载的方法:

public Map queryQuestionnaire(AppUserBean userBean, Map parameter){

因为他是根据参数的位置还有个数来调用执行调用哪个方法的,   巨坑啊, 第一次遇到这种异常, 而且菜鸟一枚 ,勿喷