下面是官方文件對於@ResponseBody註解的解釋：

Mapping the response body with the @ResponseBody annotation

The @ResponseBody annotation is similar to @RequestBody. This annotation can be put on a method and indicates that the return type should be written straight to the HTTP response body (and not placed in a Model, or interpreted as a view name). For example:

@RequestMapping(path = "/something", method = RequestMethod.PUT)
@ResponseBody
public String helloWorld() {
    return "Hello World";
}
The above example will result in the text Hello World being written to the HTTP response stream.

As with @RequestBody, Spring converts the returned object to a response body by using an HttpMessageConverter. For more information on these converters, see the previous section and Message Converters.
 

怎麼配置呢 ？需要配置MessageConverter:

<bean  
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
        <property name="messageConverters">  
            <list>  
                <ref bean="mappingJackson2HttpMessageConverter" />  
            </list>  
        </property>  
    </bean>  
    <bean id="mappingJackson2HttpMessageConverter"  
        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">  
        <property name="supportedMediaTypes">  
            <list>  
                <value>text/html;charset=UTF-8</value>  
                <value>text/json;charset=UTF-8</value>  
                <value>application/json;charset=UTF-8</value>  
            </list>  
        </property>  
    </bean>  
 

這個需要jackson jar包支援，需要 jackson-annotations,jackson-core,jackson-databind三個包，：

控制器程式碼：

@RequestMapping("House/ClassManager/addByAjax")
	@ResponseBody
	public HanBlog_Class ClassManager_addByAjax(HttpServletRequest request){
		if(request.getSession().getAttribute("hanblog_uid")==null) return null;
		HanBlog_Class objClass=new HanBlog_Class();
		return objClass;
	}
 

//|增加
		$("#hanblog_add_btn").click(function(){
			var classname=$("#add_input_name").val();
			var classintroduction=$("#add_input_introduction").val();
			alert("分類名稱:"+classname+"分類介紹:"+classintroduction);
			$.get("<c:url value="/House/ClassManager/addByAjax.do" />",function(result){
				alert(result);
			});
		});