SSM框架之SpringMVC报错No converter found for return value of type解决方法！亲测有效！

青旅半醒 2021-06-24 16:10 346阅读 0赞

本人先把出现的错误信息展示出来，相信大家跟我的错误相差无几

org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: class java.util.ArrayList
    	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.doGet(FrameworkServlet.java:866)
    	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
    	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

然后本人查阅了很多的博客，其他博主的说法都相差无几，无非就是添加三个json包或依赖，版本问题，配置文件问题，但很遗憾的是本人试遍所有的方法都没有成功解决，绝望ing。。。。。

后来干脆不用jackson-databind,jackson-annotation,jackson-core这三个包了，改用fastjson，亲测成功了！

fastjson是阿里巴巴集团推出的针对返回json格式的字符串的一个功能包，快速便捷稳定。

下面给出解决方法：

1. 导入fastjson包或添加依赖，本人以依赖方式给出

<dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.2.8</version>
    </dependency>

2. 在Springmvc配置文件中添加如下配置

<mvc:annotation-driven>
            <mvc:message-converters register-defaults="true">
                
                <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                    <property name="supportedMediaTypes">
                        <list>
                            <value>text/html;charset=UTF-8</value>
                            <value>application/json</value>
                        </list>
                    </property>
                    <property name="features">
                        <list>
                            <value>WriteMapNullValue</value>
                            <value>QuoteFieldNames</value>
                        </list>
                    </property>
                </bean>
            </mvc:message-converters>
        </mvc:annotation-driven>

之后就测试成功了！希望这篇博客能对你们有帮助，让你们少走弯路！