这篇文章主要介绍了springmvc json类型转换错误解决方案,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

在用springmvc做json数据时，返回时，提示类型转换错误

如下，

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class cn.taotao.bean.Role org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) javax.servlet.http.HttpServlet.service(HttpServlet.java:634) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) javax.servlet.http.HttpServlet.service(HttpServlet.java:741) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61) org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108) org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137) org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66) org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:347) org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:263)Root Causejava.lang.IllegalArgumentException: No converter found for return value of type: class cn.taotao.bean.Role org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:187) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:174) org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:113) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:854) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:765) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) javax.servlet.http.HttpServlet.service(HttpServlet.java:634) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) javax.servlet.http.HttpServlet.service(HttpServlet.java:741)

解决办法为

在pom中添加，只要添加上这两个jackson的支持，就可以了。

<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.8.8</version></dependency> <!-- 返回json字符串的支持 --> <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.8.8</version> </dependency>

在springmvc的controller的方法为，如下

@RequestMapping("/getRole/{id}") @ResponseBody public Role getRole(@PathVariable("id") Integer id ) { Role roleById = roleService.getRoleById(id); return roleById; }

若仍不能解决，可以在springmvc配置文件中进行如下配置（待验证）

<mvc:annotation-driven> <mvc:message-converters> <bean class="org.springframework.http.converter.StringHttpMessageConverter"/> <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/> </mvc:message-converters> </mvc:annotation-driven>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。