SpringMVC返回json數據的三種方式

1、第一種方式是spring2時代的產物，也就是每個json視圖controller配置一個Jsoniew。

如：<bean id="defaultJsonView" class="org.springframework.web.servlet.view.json.MappingJacksonJsonView"/>

或者<bean id="defaultJsonView" class="org.springframework.web.servlet.view.json.MappingJackson2JsonView"/>

同樣要用jackson的jar包。

2、第二種使用JSON工具將對象序列化成json，常用工具Jackson，fastjson，gson。

利用HttpServletResponse，然後獲取response.getOutputStream()或response.getWriter()

直接輸出。

示例：

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public class JsonUtil  

{  

    private static Gson gson=new Gson();  

    /** 

     * @MethodName : toJson 

     * @Description : 將對象轉爲JSON串，此方法能夠滿足大部分需求 

     * @param src 

     *            :將要被轉化的對象 

     * @return :轉化後的JSON串 

     */  

    public static String toJson(Object src) {  

        if (src == null) {  

            return gson.toJson(JsonNull.INSTANCE);  

        }  

        return gson.toJson(src);  

    }  

}

3、第三種利用spring mvc3的註解@ResponseBody

例如：

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@ResponseBody  

  @RequestMapping("/list")  

  public List<String> list(ModelMap modelMap) {  

    String hql = "select c from Clothing c ";  

    Page<Clothing> page = new Page<Clothing>();  

    page.setPageSize(6);  

    page  = clothingServiceImpl.queryForPageByHql(page, hql);  

    return page.getResult();  

  }

然後使用spring mvc的默認配置就可以返回json了，不過需要jackson的jar包哦。

注意：當springMVC-servlet.xml中使用<mvc:annotation-driven />時，如果是3.1之前已經默認注入AnnotationMethodHandlerAdapter，3.1之後默認注入RequestMappingHandlerAdapter只需加上上面提及的jar包即可!

如果是手動注入RequestMappingHandlerAdapter 可以這樣設置

配置如下：

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background-color: inherit;">  </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">        <span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">p:ignoreDefaultModelOnRedirect</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"true"</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">            <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">property</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">name</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"messageConverters"</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">                <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">list</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">                    <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">bean</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">class</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">/></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">                <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">list</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">            <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">property</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">        <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">bean</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); font-weight: bold; background-color: inherit;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li></ol></div>

添加包
jackson-mapper-asl-*.jar
jackson-core-asl-*.jar