java - 处理 json 和表单参数的 Spring MVC 方法

Question

我想在单个 spring mvc 方法中处理内容类型 application/x-www-form-urlencoded 和 application/json。

我在休息服务中要求接受输入作为表单参数或 json。我可以通过编写两种方法来实现这一点。无论是表单参数还是 json，响应始终是 json。

@RequestMapping (method = RequestMethod.POST, produces = {"application/json"},
        consumes = {"application/x-www-form-urlencoded"})
public @ResponseBody Book createBook(Book book)
        throws Exception {
    return book;
}

@RequestMapping (method = RequestMethod.POST, produces = {"application/json"},
        consumes = {"application/json"})
public @ResponseBody Book createBookJSON(@RequestBody Book book)
        throws Exception {
    return book;
} 

是否可以将这两种方法合二为一并使其发挥作用？任何帮助都感激不尽。

编辑

我已经实现了相同的，我的 Controller 和配置如下所示，但是当我发送 json 请求时，我得到空值作为响应。

当我发送表单参数时，它工作正常。帮我找出问题所在。

Controller 方法

 @RequestMapping (method = RequestMethod.POST, produces = {"application/json", "application/xml"}, consumes = {"application/x-www-form-urlencoded", "application/json"})                   
    public @ResponseBody Book createBook(Book book)
            throws Exception {
        return book;
    }

servlet 上下文

<mvc:view-controller path="/" view-name="index"/>

<context:annotation-config />

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

<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>

<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
    <property name="order" value="1" />
    <property name="mediaTypes">
        <map>
            <entry key="xml" value="application/xml" />
            <entry key="json" value="application/json" />
        </map>
    </property>
    <property name="defaultViews">
        <list>
            <!-- JSON View -->
            <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" />

            <!-- JAXB XML View -->
            <bean class="org.springframework.web.servlet.view.xml.MarshallingView">
                <constructor-arg>
                    <ref bean="jaxb2Marshaller" />
                </constructor-arg>
            </bean>

        </list>
    </property>
    <property name="ignoreAcceptHeader" value="true" />
</bean>

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" >
    <property name="order" value="1" />
    <property name="messageConverters">
        <list>
            <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" >
                <property name="supportedMediaTypes" value="application/json"/>
            </bean>

            <bean id="marshallingHttpMessageConverter" class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter">
                <property name="marshaller" ref="jaxb2Marshaller" />
                <property name="unmarshaller" ref="jaxb2Marshaller" />
                <property name="supportedMediaTypes" value="application/xml"/>
            </bean>

            <bean class = "org.springframework.http.converter.FormHttpMessageConverter">
                <property name="supportedMediaTypes" value = "application/x-www-form-urlencoded" />
            </bean>

            <bean class = "org.springframework.http.converter.StringHttpMessageConverter">
                <property name="supportedMediaTypes" value = "text/plain;charset=UTF-8" />
            </bean>
        </list>
    </property>
</bean>

<bean id="jaxb2Marshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller" >
    <property name="classesToBeBound">
        <list>
            <value>com.lt.domain.Book</value>
        </list>
    </property>
</bean>

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="order" value="2" />
    <property name="prefix" value="/WEB-INF/views/"/>
    <property name="suffix" value=".jsp"/>
</bean>

Answer 1

@RequestMapping (method = RequestMethod.POST)
public Book createBook(Book book)
        throws Exception {
    return book;
}

consumes 接受它可以消费的任何字符串数组，spring bean 绑定(bind)应该处理其余部分。问题可能是您没有正确设置 bean 绑定(bind)以便自动编码和解码 json。使用@RequestBody 和@RepsonseBody 并不是最佳选择恕我直言。

确保将 jackson 添加到您的依赖项中

<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>latest</version>
</dependency>

并使用contentnegotiatingviewresolver

<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
    <property name="mediaTypes">
        <map>
            <entry key="htm" value="text/htm"/>
            <entry key="html" value="text/html"/>
            <entry key="json" value="application/json"/>
        </map>
    </property>
    <property name="viewResolvers">
        <list>
            <bean class="org.springframework.web.servlet.view.BeanNameViewResolver"/>
            <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
                <property name="prefix" value="/WEB-INF/jsp/"/>
                <property name="suffix" value=".jsp"/>
            </bean>
        </list>
    </property>

    <property name="defaultViews">
        <list>
            <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView"/>

        </list>
    </property>
</bean>

确保在您的客户端应用程序中将接受 header 设置为所需的值。您还应该能够在 requestmethod 注释中删除所有生产和使用数据