我得到的错误:
Feb 04, 2016 9:20:52 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [dispatcher] in context with path
[/Example] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: Unrecognized Type: [null]] with rootcause
java.lang.IllegalArgumentException: Unrecognized Type: [null]
atcom.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1109)
at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:566)
at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:602)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.getJavaType(AbstractJackson2HttpMessageConverter.java:311)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:249)
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:100)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:222)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:153)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:165)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:80)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at …