springmvc 返回json数据

1、在lib中加入jackson.jar包

2、在请求函数上进行标注返回类型，ResponseBody也可以放上边

    @RequestMapping(value="/json",method=RequestMethod.GET, produces="application/json;charset=UTF-8")
    public @ResponseBody User getUserJson(){
        User user = new User();
        user.setId(12);
        user.setName("zhangsan");
        return user;
    }