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. 

<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> 

@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); 
      }); 
    });