Jackson 和 fastJSON 导包异常

内容

一、异常信息

HTTP Status 400 - type Status report

message

org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type

二、解决办法

1、异常

1. 异常截图
   

2. 详细信息

exception
org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: class com.yy.homework.qo.JsonResult
	org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:226)
	org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:180)
	org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.37 logs.

3. 错误原因
   使用 JSON 时，导入的包是 fastJSON 或者没有导包，我们应该导入 jackson 包

2、解决

导入 Jackson 包即可，fastJSON 包有时候有问题