springMVC 处理json ------ HttpMessageConverter 接口

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.8.7</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.8.7</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.7</version>
</dependency>

@Controller
@RequestMapping("/user")
public class UserController
{
    @Autowired
    private UserService userService;
    
    @RequestMapping("/getUserList")
    @ResponseBody
    public Map<String, Object> getUserList(Model model)
    {
        List<User> userlist = userService.getUserList();
        Map<String, Object> map = new HashMap<>();
        map.put("aaData", userlist);
        return map;
    }
}