package me.yanand.pojo;
import javax.validation.constraints.Max;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
public class User {
  @NotBlank(message = "姓名不能為空")
  private String name;
  @NotNull(message = "年齡不能為空")
  @Max(value = 100,message = "年齡太大")
  private Integer age;
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public Integer getAge() {
    return age;
  }
  public void setAge(Integer age) {
    this.age = age;
  }

package me.yanand.controller;
import me.yanand.pojo.User;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.validation.Valid;
@RestController
public class TestController {
  @RequestMapping("/")
  String hello(@RequestBody @Valid User user, BindingResult bindingResult){
    if(bindingResult.hasErrors()){
      return bindingResult.getFieldError().getDefaultMessage();
    }
    return "ok";
  }
}