json - 配置jacksonObjectMapper在Spring MVC 3中不起作用

Question

我的目标是将spring mvc 3配置为在json响应中不返回“null”对象。
我问了how to configure spring mvc 3 to not return "null" object in json response?问题。我得到的建议是配置ObjectMapper，将序列化包含设置为JsonSerialize.Inclusion.NON_NULL。因此，基于Spring configure @ResponseBody JSON format，我在spring配置文件中进行了以下更改。但是在应用程序启动期间，出现错误“拒绝的bean名称'jacksonObjectMapper':没有URL路径标识为org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping:86-AbstractDetectingUrlHandlerMapping.java”。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- Configures the @Controller programming model -->
    <mvc:annotation-driven />

    <!-- Forwards requests to the "/" resource to the "welcome" view -->
    <!--<mvc:view-controller path="/" view-name="welcome"/>-->

    <!-- Configures Handler Interceptors -->    
    <mvc:interceptors>
        <!-- Changes the locale when a 'locale' request parameter is sent; e.g. /?locale=de -->
        <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor" />
    </mvc:interceptors>

   <!-- Saves a locale change using a cookie -->
    <bean id="localeResolver" class="org.springframework.web.servlet.i18n.CookieLocaleResolver" />


    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                    <property name="objectMapper" ref="jacksonObjectMapper" />
                </bean>
            </list>
        </property>
    </bean>

    <bean id="jacksonObjectMapper" class="org.codehaus.jackson.map.ObjectMapper" />
    <bean id="jacksonSerializationConfig" class="org.codehaus.jackson.map.SerializationConfig"
    factory-bean="jacksonObjectMapper" factory-method="getSerializationConfig" />
    <bean class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
        <property name="targetObject" ref="jacksonSerializationConfig" />
        <property name="targetMethod" value="setSerializationInclusion" />
        <property name="arguments">
            <list>
                <value type="org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion">NON_DEFAULT</value>
            </list>
        </property>
    </bean>


  <!-- Resolves view names to protected .jsp resources within the /WEB-INF/views directory -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

我不知道为什么它被拒绝了。任何建议，不胜感激!

Answer 1

<mvc:annotation-driven />和AnnotationMethodHandlerAdapter不能一起使用。 (引用:spring forum thread)。可能的解决方案

不要使用<mvc:annotation-driven/>。声明bean:DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter以及其他设置(例如验证，格式设置)。

使用spring 3.1，它具有<mvc:message-converters>(ref:Spring jira)