在访问 webService 时获取 NullPointerException.我该如何解决 [英] getting NullPointerException whill accessing a webService. How can I resolve it
问题描述
我一直在编写一个项目，该项目充当服务器并启动并运行可供客户端使用的服务.我的服务器应用程序是一个基于 Spring MVC 3 框架的简单 CRUD 应用程序.在名为 Person 的单个表的记录上.我的 WebServices 是 SOAP1.1 servcies，并且在我在 TomCat 上部署我的项目时处于活动状态.我可以在本地主机上访问它的 wsdl，我可以通过在 tomcat 上运行和部署该项目来访问这些 web 服务.我通过重新调整 Service 方法中的标志来测试服务.现在的问题是.如果我通过其控制器在 Web 上运行服务器应用程序，我就可以通过 Web 界面正确执行 crud.所有组件 Repository、Service DAO 都被正确注释并在网络上工作.但是当我尝试通过我的服务做同样的工作时.我得到了 Autowired 对象的 NullPointerExceptions.
I have been writing a project who acts as a server and have services up and running available to be consumed by client side. My Server application is a Simple CRUD application based on Spring MVC 3 framework. over records of a single table named Person. My WebServices are SOAP1.1 servcies and are live when once I deploy my project on TomCat. I can access its wsdl on localhost and I can these webservices by running and deploying that project over tomcat. I have tested serives by retuning flags from Service methods. Now issue is that. If I run Server application over the web through its controller, I am able to do crud through web interface properly. All the components Repository, Service DAO's are properly annotated and works over web. But when I try to do same work through my services. I get NullPointerExceptions for Autowired objects.
以下是一个例外.请帮助并在评论中表达您的想法.
Following is an exception. Please help and through your thoughts in comments.
WARN org.apache.cxf.phase.PhaseInterceptorChain - Application {http://service.accounting.cassit.com/}personService#{http://service.accounting.cassit.com/}deletePerson has thrown exception, unwinding now
org.apache.cxf.interceptor.Fault
at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:155)
at org.apache.cxf.jaxws.AbstractJAXWSMethodInvoker.createFault(AbstractJAXWSMethodInvoker.java:86)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:121)
at org.apache.cxf.jaxws.JAXWSMethodInvoker.invoke(JAXWSMethodInvoker.java:61)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:75)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at org.apache.cxf.workqueue.SynchronousExecutor.execute(SynchronousExecutor.java:37)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:106)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:255)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:113)
at org.apache.cxf.transport.servlet.ServletDestination.invoke(ServletDestination.java:102)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:464)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:188)
at org.apache.cxf.transport.servlet.AbstractCXFServlet.invoke(AbstractCXFServlet.java:148)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:179)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:103)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:159)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at com.cassit.accounting.service.PersonServiceImpl.deletePerson(PersonServiceImpl.java:47)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:173)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:89)
查看此行并检查第 47 行或相应的 java 文件时.我开始知道我正在访问 AutoWired 属性.为什么会这样?
When look at this line and inspected line number 47 or respective java file. I come to know that I was accessing an AutoWired property. Why is it so?
Caused by: java.lang.NullPointerException
at com.cassit.accounting.service.PersonServiceImpl.deletePerson(PersonServiceImpl.java:47)
最好的问候，
推荐答案
参见 第 4.9 节，基于注解的容器配置，在 Spring 参考中.
See Section 4.9, Annotation-based container configuration, in the Spring Reference.
重要的一点是第 4.9.1 节之前的注释，引用:
The important bit is the note right before Section 4.9.1, quoting:
<context:annotation-config/> 放在 WebApplicationContext 的 DispatcherServlet 中，它只会检查 @Autowired beans 在您的控制器中，而不是您的服务中.参见 第 16.2 节，DispatcherServlet" 了解更多信息.
<context:annotation-config/>only looks for annotations on beans in the same application context in which it is defined. This means that, if you put<context:annotation-config/>in aWebApplicationContextfor aDispatcherServlet, it only checks for@Autowiredbeans in your controllers, and not your services. See Section 16.2, "The DispatcherServlet" for more information.
很可能你的 @Service 注释类没有被扫描；试试:
It is likely your @Service-annotated classes are not being scanned; try:
<context:component-scan base-package="your.service.package" />
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