java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.Has

今天使用了一个开源项目 是基于SpringMVC架构编写的项目  发现在Controller里加入@ResponseBody注解之后 返回的类型转换成JSON对象会出错 

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org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.HashMap

    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:622)

    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)

    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

 

java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.HashMap

    org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:158)

    org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:133)

    org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:165)

    org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:80)

    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126)

    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:806)

    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:729)

    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)

    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)

    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)

    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:622)

    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)

    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note The full stack trace of the root cause is available in the Apache Tomcat/8.0.21 logs.

 

Apache Tomcat/8.0.21

spring-mvc里加入

   <bean id="mappingJacksonHttpMessageConverter"

          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">

        <property name="supportedMediaTypes">

            <list>

                <value>application/json;charset=UTF-8</value>

            </list>

        </property>

    </bean>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">

        <property name="messageConverters">

            <list>

                <ref bean="mappingJacksonHttpMessageConverter"/>

            </list>

        </property>

    </bean>

pom文件里加入

<dependency><groupId>org.codehaus.jackson</groupId><artifactId>jackson-mapper-asl</artifactId><version>1.9.13</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-annotations</artifactId><version>2.6.1</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-core</artifactId><version>2.6.1</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.6.1</version></dependency><dependency><groupId>org.json</groupId><artifactId>json</artifactId><version>20140107</version></dependency>