基于Spring Validation自定义校验注解

常用的原生校验注解有：

@NotNull 所有对象判空
@NotBlank 字符串判空
@NotEmpty 集合判空

自定义校验注解实现方式：

引入依赖

如果spring-boot版本小于2.3.x，spring-boot-starter-web会自动传入hibernate-validator依赖。如果spring-boot版本大于2.3.x，则需要手动引入依赖：

    org.hibernate
    hibernate-validator
    6.0.1.Final

定义校验注解

自定义一个校验注解，针对字符串参数校验，校验逻辑是字符串必须是"xzh"。

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE_USE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

/**
 * @author 向振华
 * @date 2022/11/23 16:52
 */
@Documented
@Constraint(validatedBy = {EqualsXzhValidator.class})
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
@Retention(RUNTIME)
public @interface EqualsXzh {

    String message() default "必须是xzh";

    Class[] groups() default { };

    Class[] payload() default { };
}

实现校验逻辑

校验逻辑是字符串必须是"xzh"。

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

/**
 * @author 向振华
 * @date 2022/11/23 16:56
 */
public class EqualsXzhValidator implements ConstraintValidator {

    public EqualsXzhValidator() {
    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        // 自定义校验规则，字段的value必须是"xzh"，否则抛异常
        return "xzh".equals(value);
    }
}

全局异常捕获处理

参数校验会默认抛出MethodArgumentNotValidException异常，通常使用全局异常捕获拦截，然后返回提示信息出去 。

import com.xzh.exception.BusinessException;
import com.xzh.web.ApiResponse;
import lombok.extern.slf4j.Slf4j;
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 javax.servlet.http.HttpServletRequest;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.StringJoiner;

/**
 * 全局异常捕获处理
 *
 * @author 向振华
 * @date 2022/11/23 16:52
 */
@Slf4j
@RestControllerAdvice
public class GlobalExceptionHandler {

    /**
     * 异常处理程序
     *
     * @param request
     * @param exception
     * @return
     */
    @ExceptionHandler(value = Exception.class)
    public Object handler(HttpServletRequest request, Exception exception) {
        String errorLog = this.errorLog(request, exception);
        log.error("全局异常捕获日志 ---> {}", errorLog);

        String message;
        if (exception instanceof MethodArgumentNotValidException) {
            MethodArgumentNotValidException e = (MethodArgumentNotValidException) exception;
            BindingResult bindingResult = e.getBindingResult();
            StringJoiner sj = new StringJoiner("，");
            for (FieldError fieldError : bindingResult.getFieldErrors()) {
                String longField = fieldError.getField();
                String shortField = longField.substring(longField.lastIndexOf(".") + 1);
                String defaultMessage = fieldError.getDefaultMessage();
                sj.add(shortField + defaultMessage);
            }
            message = sj.toString();
        } else if (exception instanceof BusinessException) {
            BusinessException e = (BusinessException) exception;
            message = e.getMessage();
        } else {
            message = "系统异常，请稍后重试";
        }

        return ApiResponse.fail(message);
    }


    private String errorLog(HttpServletRequest request, Exception exception) {
        StringWriter sw = new StringWriter();
        sw.append(String.format("[接口] %s\n", request.getRequestURL()));
        exception.printStackTrace(new PrintWriter(sw));
        return sw.toString();
    }
}

参数校验工具

 参数校验也可以使用工具类进行校验，校验不通过抛出业务异常（也会被全局异常捕获拦截）

import com.xzh.exception.BusinessException;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.Set;
import java.util.StringJoiner;

/**
 * 参数校验工具
 *
 * @author 向振华
 * @date 2022/11/23 16:52
 */
public class ValidatedUtils {

    private static final Validator VALIDATOR;

    static {
        VALIDATOR = Validation.buildDefaultValidatorFactory().getValidator();
    }

    private ValidatedUtils() {
    }

    public static void verify(Object object, Class... groups) {
        Set> constraintViolations = VALIDATOR.validate(object, groups);
        if (!constraintViolations.isEmpty()) {
            StringJoiner sj = new StringJoiner("，");
            for (ConstraintViolation