NullPointerExceptions thrown whenever an ExceptionHandler is called

[andyfields]

I have exception handlers in my controllers. They return the correct values to the client, but an NPE is being put in the log whenever they are called. I was able to reproduce this by creating a very simple app using Spring Initializer and adding a simple controller to it.

I am using spring-boot-starter-data-rest in my app. It is not referenced in the sample program I am enclosing. If I omit it from the pom, the NPE is not thrown in the log. I would be very grateful if you could tell me how to avoid the NPE without omitting this.

Run the app and call the url: http://localhost:8080/test/findAllErr

It returns a 400 status code, but you will also see an NPE in the log that should not be there. The exception is attached:

NPE.rtf.zip

demo 2.zip

[philwebb]

Here's the stack trace

java.lang.NullPointerException: null
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:132) ~[spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.doResolveHandlerMethodException(ExceptionHandlerExceptionResolver.java:384) ~[spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver.doResolveException(AbstractHandlerMethodExceptionResolver.java:59) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:136) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:74) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1218) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1030) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:980) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.7.RELEASE.jar!/:4.3.7.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_111]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_111]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.11.jar!/:8.5.11]
	at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111]

[philwebb]

Thanks for the sample project, it helped me track down the cause. I think we'll need a fix in Spring Data REST. I've raised DATAREST-1031 for that team to look at.

[odrotbohm]

That's just been fixed in Spring Data REST and I verfied the sample project to work with the fix.