导入依赖

        <!--springboot 引入Hibernate校验-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

link:https://www.imooc.com/article/22115

自定义一个Controller

import com.example.demo.pojo.User;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
 
import javax.validation.Valid;
/**
 * @Author: betsyxw
 * @Date: 
 */
@RestController
public class ValiController {
    @PostMapping(value = "/",produces = "application/json;charset=UTF-8")
    public User vali(@RequestBody @Valid User user){
        return user;
    }
}

自定义实体类

import javax.validation.constraints.Max;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
 
/**
 * @Author: betsyxw
 * @Date: 
 */
public class User {
    @NotBlank(message = "这个姓名不能为空")
    private String name;
    @NotNull(message = "这个年龄不能为空")
    @Max(value = 105,message = "太大了")
    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;
    }
}

自定义全局异常处理器

import com.example.demo.pojo.ErrorMsg;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ResponseBody;
 
import java.util.ArrayList;
import java.util.List;
 
/**
 * @Author: betsyxw
 * @Date: 
 */
@ControllerAdvice
public class ExceptionHandlerContrller {
 
 
    @ExceptionHandler(MethodArgumentNotValidException.class)
    @ResponseBody
    public List<ErrorMsg> exception(MethodArgumentNotValidException e) {
        BindingResult bindingResult = e.getBindingResult();
        List<ObjectError> allErrors = bindingResult.getAllErrors();
        List<ErrorMsg> errorMsgs = new ArrayList<>();
 
        allErrors.forEach(objectError -> {
            ErrorMsg errorMsg = new ErrorMsg();
            FieldError fieldError = (FieldError)objectError;
            errorMsg.setField(fieldError.getField());
            errorMsg.setObjectName(fieldError.getObjectName());
            errorMsg.setMessage(fieldError.getDefaultMessage());
            errorMsgs.add(errorMsg);
        });
        return errorMsgs;
    }
}

PostMan测试下

[
    {
        "field": "name",
        "message": "这个姓名不能为空",
        "objectName": "user"
    },
    {
        "field": "age",
        "message": "这个年龄不能为空",
        "objectName": "user"
    }
]