SpringMVC解析或者返回json：三步曲

1. 導入jar包（三個jar包版本要一樣，否則可能會異常）
   

2. controller
   例子：
   url自行替換

   @Controller
   @RequestMapping("user")
   public class UserController {
       @Resource
       private UserService userService;
   
       @RequestMapping(value = "/login", method = RequestMethod.POST, consumes="application/json")
       @ResponseBody
       public User testUser(@RequestBody User inUser) {
           User outUser = userService.selectByLoginnameAndPassword(inUser);
           return outUser;
       }
   }

3. 前臺json字段要和後臺javabean字段一致，區分大小寫