Springboot @validated

<parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.7.2</version>
</parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.7.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
        </dependency>
		<!-- 数据验证的依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
    </dependencies>

package com.hopeful.pojo;
import lombok.Data;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.io.Serializable;
@Data
public class User implements Serializable {
    private Integer id;
    @NotNull(message = "姓名不能为空")
    private String name;
    @NotNull
    @Size(min = 6,message = "密码不能没空，且不能少于6位")
    private String pwd;
}

package com.hopeful;
import com.hopeful.pojo.User;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
@RequestMapping("/user")
@RestController
public class controller {
    @RequestMapping("/hello")
    public String hello() {
        return "hello";
    }
    @PostMapping("/insertUser")
    public String insert2(@Validated @RequestBody User user) {
        System.out.println(user);
        return "新增成功";
    }
}

package com.hopeful;
import com.hopeful.pojo.User;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RequestMapping("/user")
@RestController
public class controller {
    @RequestMapping("/hello")
    public String hello() {
        return "hello";
    }
    @GetMapping("/insertUser")
    public User insert(@Validated User user) {
        return user;
    }
    @PostMapping("/insertUser")
    public String insert2(@Validated @RequestBody User user, BindingResult bindingResult) {
        if(bindingResult.hasErrors()) {
            String msg = "";
            msg = getString(bindingResult, msg);
            return msg;
        }
        System.out.println(user);
        return "新增成功";
    }
    public static String getString(BindingResult bindingResult, String msg) {
        List<FieldError> fieldErrors = bindingResult.getFieldErrors();
        int size = fieldErrors.size();
        for (int i = 0; i < size; i++) {
            FieldError fieldError = fieldErrors.get(i);
            if(fieldError != null) {
                msg += fieldError.getDefaultMessage();
            }
            if(i < size - 1) {
                msg += ";";
            }
        }
        return msg;
    }
}

package com.hopeful.pojo.common;
import org.springframework.validation.BindException;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import javax.validation.ConstraintViolationException;
import javax.validation.ValidationException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@ControllerAdvice
@ResponseBody
public class globalException extends RuntimeException {
    @ExceptionHandler(value = {BindException.class, ValidationException.class,MethodArgumentNotValidException.class})
    public String MethodArgumentNotValidException(Exception e) {
        String msg = "";
        if (e instanceof MethodArgumentNotValidException) {
            BindingResult bindingResult = ((MethodArgumentNotValidException) e).getBindingResult();
            // getFieldError获取的是第一个不合法的参数(P.S.如果有多个参数不合法的话)
            //FieldError fieldError = bindingResult.getFieldError();
            //if (fieldError != null) {
            //    msg = fieldError.getDefaultMessage();
            //}
            List<FieldError> fieldErrors = bindingResult.getFieldErrors();
            int size = fieldErrors.size();
            for (int i = 0; i < size; i++) {
                FieldError fieldError = fieldErrors.get(i);
                if(fieldError != null) {
                    msg += fieldError.getDefaultMessage();
                }
                if(i < size - 1) {
                    msg += ";";
                }
            }
        } else if (e instanceof BindException) {
            // getFieldError获取的是第一个不合法的参数(P.S.如果有多个参数不合法的话)
            FieldError fieldError = ((BindException) e).getFieldError();
            if (fieldError != null) {
                msg = fieldError.getDefaultMessage();
            }
        } else if (e instanceof ConstraintViolationException) {
            /*
             * ConstraintViolationException的e.getMessage()形如
             *     {方法名}.{参数名}: {message}
             *  这里只需要取后面的message即可
             */
            msg = e.getMessage();
            if (msg != null) {
                int lastIndex = msg.lastIndexOf(':');
                if (lastIndex >= 0) {
                    msg = msg.substring(lastIndex + 1).trim();
                }
            }
            /// ValidationException 的其它子类异常
        } else {
            msg = "处理参数时异常";
        }
        return msg;
    }
}