依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

规范内嵌的约束注解

异常统一处理

import com.fan.entity.Result;
import lombok.extern.slf4j.Slf4j;
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.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.HashMap;
import java.util.Map;

/**
 * 校验异常拦截
 */
@Slf4j
@RestControllerAdvice(basePackages = "com.fan.controller")
public class ValidationExceptionConfig {

    @ExceptionHandler(value = {MethodArgumentNotValidException.class, BindException.class})
    public Result<Map<String, String>> handleValidationException(Exception e) {
        BindingResult bindingResult = null;
        if (e instanceof MethodArgumentNotValidException) {
            bindingResult = ((MethodArgumentNotValidException) e).getBindingResult();
        } else if (e instanceof BindException) {
            bindingResult = ((BindException) e).getBindingResult();
        }
        Map<String, String> errorMap = new HashMap<>();
        assert bindingResult != null;
        // 获取所有错误参数
        bindingResult.getFieldErrors().forEach((fieldError ->
                errorMap.put(fieldError.getField(), fieldError.getDefaultMessage())));
        // 获取第一个错误参数
        String msg = "";
        for (FieldError fieldError : bindingResult.getFieldErrors()) {
            msg = fieldError.getDefaultMessage();
            break;
        }
        return Result.build(Result.CODE_FAIL, msg, errorMap);
    }

}

或者

import com.fan.model.Result;
import lombok.extern.slf4j.Slf4j;
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.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.Map;
import java.util.Objects;

/**
 * 校验异常拦截
 */
@Slf4j
@RestControllerAdvice(basePackages = "com.fan.controller")
public class ValidationExceptionConfig {

    /**
     * 拦截参数校验错误的消息
     */
    @ExceptionHandler(value = {MethodArgumentNotValidException.class, BindException.class})
    public Result<Map<String, String>> handleValidationException(Exception e) {
        BindingResult bindingResult = null;
        if (e instanceof MethodArgumentNotValidException) {
            bindingResult = ((MethodArgumentNotValidException) e).getBindingResult();
        } else if (e instanceof BindException) {
            bindingResult = ((BindException) e).getBindingResult();
        }
        // 获取第一个错误参数
        String msg = "请求参数错误";
        if (Objects.nonNull(bindingResult)) {
            for (FieldError fieldError : bindingResult.getFieldErrors()) {
                msg = fieldError.getDefaultMessage();
                break;
            }
        }
        return Result.failMsg(msg);
    }

}

使用示例

使用@Valid指定需要校验。

/**
 * 登录接口
 */
@RequestMapping("/login")
public Result<String> login(@RequestBody @Valid LoginDto loginDto) {
    try {
        System.out.println(loginDto);
        return Result.successMsg("登录成功");
    } catch (Exception e) {
        log.error("登录异常：" + e);
        return Result.errorMsg(e.getMessage());
    }
}

校验示例

public class StudentBean implements Serializable{
    @NotBlank(message = "用户名不能为空")
    private String name;
    @Min(value = 18, message = "年龄不能小于18岁")
    private Integer age;
    @Pattern(regexp = "^((13[0-9])|(14[5,7,9])|(15([0-3]|[5-9]))|(166)|(17[0,1,3,5,6,7,8])|(18[0-9])|(19[8|9]))\\d{8}$", message = "手机号格式错误")
    private String phoneNum;
    @Email(message = "邮箱格式错误")
    private String email;
    @MyConstraint
    private String className;
    @Size(min=2, max=30, message="Name must be between 2 and 30 characters")
    private String name;
 
    @NotNull(message = "任课老师不能为空")
    @Size(min = 1, message = "至少有一个老师")
    private List<TeacherBean> teacherBeans;
}