Spring MVC No converter found for return value of type 解决方法

1.在pom.xml中配置

 <properties>    <jackson.version>2.8.5</jackson.version></properties><!-- jackson -->    <dependency>        <groupId>com.fasterxml.jackson.core</groupId>        <artifactId>jackson-core</artifactId>        <version>${jackson.version}</version>    </dependency>    <dependency>        <groupId>com.fasterxml.jackson.core</groupId>        <artifactId>jackson-databind</artifactId>        <version>${jackson.version}</version>    </dependency>    <dependency>        <groupId>com.fasterxml.jackson.core</groupId>        <artifactId>jackson-annotations</artifactId>        <version>${jackson.version}</version>    </dependency>

在 spring mvc 的配置文件 dispatcher-servlet.xml 中配置

<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>

如果需要返回的一个对象的JSON，一定要确保相应的对象有对应的set 和 get函数，否则也会报错

type Exception reportmessage Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayListdescription The server encountered an internal error that prevented it from fulfilling this request.exceptionorg.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList    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 causejava.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList    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:132)    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)    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/8.5.11 logs.