SpringMVC返回json格式的数据

一 . 通过 jackson 返回JSON数据

1. 引入JAR包

  jackson-core-asl-1.9.13.jar

    jackson-core-lgpl-1.9.13.jar

    jackson-mapper-asl-1.9.13.jar

    jackson-mapper-lgpl-1.9.13.jar

2. Spring配置文件添加

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

        

3. Controller里面修改返回值类型

@RequestMapping(value = "{username}") public @ResponseBody  User find(@PathVariable String username, Model model, HttpServletResponse response) {     User u = users.get(username);    return u; }

二 . 通过 PrintWriter 输出字符串返回JSON数据

@RequestMapping(value = "{username}") public void find2_1(@PathVariable String username, HttpServletResponse response) {      Gson gson = new Gson();      User u = users.get(username);      String us = gson.toJson(u);     // 需要设置编码格式,否则可能出现乱码      response.setContentType("application/json");      response.setCharacterEncoding("UTF-8");      try {           PrintWriter out = response.getWriter();           out.print(us);      } catch (IOException e) {           e.printStackTrace();      } }