Springmvc 4.x利用@ResponseBody返回Json數據的方法

更新時間：2018年04月19日 14:12:28 作者：涵涵YH

這篇文章主要介紹了Springmvc 4.x利用@ResponseBody返回Json數據的方法，小編覺得挺不錯的，現在分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

下面是官方文檔對于@ResponseBody注解的解釋：

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.

@ResopnseBody注解能夠直接把控制器返回變量（String）直接返回給瀏覽器,也可以通過配置后，把對象序列化成Json數據返回給瀏覽器！如果為 null 就會返回空白。

怎么配置呢？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>

下面貼出在官方文檔中的位置：

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

控制器代碼：

@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; 
  }

jquery代碼：

//|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); 
      }); 
    });

運行返回例子：