Java中如何在AbstractValidator中跳过classId验证规则？

方案1：通过条件判断动态启用规则 #

在classId的验证规则中添加when()条件，根据业务场景的标识决定是否执行验证。比如可以给MyStudent增加一个业务场景标识字段，或者通过外部上下文判断：

public class MyValidator extends AbstractValidator<MyStudent> {

  public MyValidator() {
    ruleFor(myStudent -> myStudent.getStudentId())
        .must(getStudentId -> CommonValidatorUtils.isValidUUID(getStudentId))
        .withMessage("The getStudentId value is invalid");

    ruleFor(myStudent -> myStudent.getGradeId())
        .must(getGradeId -> !Strings.isNullOrEmpty(getGradeId))
        .withMessage("The getGradeId is invalid");

    ruleFor(myStudent -> myStudent.getEmail())
        .must(CommonValidatorUtils::isEmailValidTemplate)
        .withMessage("The email is invalid value");

    ruleFor(myStudent::getClassId)
        .must(CommonValidatorUtils::isValidUUID)
        .withMessage("The getClassId value is invalid.")
        // 仅当不需要跳过classId验证时执行规则，条件可根据实际业务调整
        .when(myStudent -> !myStudent.isSkipClassIdValidation());
  }

}

使用时，在无需验证classId的业务场景中，给MyStudent对象设置skipClassIdValidation=true即可。

方案2：拆分验证器，按需选择使用 #

将通用验证规则抽离到基础验证器，再分别创建包含/不包含classId验证的子类，业务场景根据需求选择对应的验证器：

// 基础验证器：包含通用规则
public class BaseStudentValidator extends AbstractValidator<MyStudent> {
  public BaseStudentValidator() {
    ruleFor(myStudent -> myStudent.getStudentId())
        .must(getStudentId -> CommonValidatorUtils.isValidUUID(getStudentId))
        .withMessage("The getStudentId value is invalid");

    ruleFor(myStudent -> myStudent.getGradeId())
        .must(getGradeId -> !Strings.isNullOrEmpty(getGradeId))
        .withMessage("The getGradeId is invalid");

    ruleFor(myStudent -> myStudent.getEmail())
        .must(CommonValidatorUtils::isEmailValidTemplate)
        .withMessage("The email is invalid value");
  }
}

// 需要验证classId的场景用这个
public class StudentWithClassIdValidator extends BaseStudentValidator {
  public StudentWithClassIdValidator() {
    super();
    ruleFor(myStudent::getClassId)
        .must(CommonValidatorUtils::isValidUUID)
        .withMessage("The getClassId value is invalid.");
  }
}

// 不需要验证classId的场景用这个
public class StudentWithoutClassIdValidator extends BaseStudentValidator {
  public StudentWithoutClassIdValidator() {
    super();
    // 不添加classId验证规则
  }
}

方案3：通过构造参数控制规则开关 #

给验证器添加一个布尔参数，在实例化时决定是否启用classId验证：

public class MyValidator extends AbstractValidator<MyStudent> {

  public MyValidator(boolean enableClassIdValidation) {
    ruleFor(myStudent -> myStudent.getStudentId())
        .must(getStudentId -> CommonValidatorUtils.isValidUUID(getStudentId))
        .withMessage("The getStudentId value is invalid");

    ruleFor(myStudent -> myStudent.getGradeId())
        .must(getGradeId -> !Strings.isNullOrEmpty(getGradeId))
        .withMessage("The getGradeId is invalid");

    ruleFor(myStudent -> myStudent.getEmail())
        .must(CommonValidatorUtils::isEmailValidTemplate)
        .withMessage("The email is invalid value");

    // 根据传入的开关决定是否添加classId验证规则
    if (enableClassIdValidation) {
      ruleFor(myStudent::getClassId)
          .must(CommonValidatorUtils::isValidUUID)
          .withMessage("The getClassId value is invalid.");
    }
  }

}

使用示例：

// 需要验证classId时
MyValidator validatorWithClassId = new MyValidator(true);
// 不需要验证classId时
MyValidator validatorWithoutClassId = new MyValidator(false);

方案4：使用规则分组（Rule Sets） #

利用FluentValidation的规则分组功能，将classId验证归类到单独分组，验证时按需指定是否包含该分组：

首先定义分组标识：

public interface ValidateClassIdGroup {}

修改验证器：

public class MyValidator extends AbstractValidator<MyStudent> {

  public MyValidator() {
    // 通用规则，默认分组
    ruleFor(myStudent -> myStudent.getStudentId())
        .must(getStudentId -> CommonValidatorUtils.isValidUUID(getStudentId))
        .withMessage("The getStudentId value is invalid");

    ruleFor(myStudent -> myStudent.getGradeId())
        .must(getGradeId -> !Strings.isNullOrEmpty(getGradeId))
        .withMessage("The getGradeId is invalid");

    ruleFor(myStudent -> myStudent.getEmail())
        .must(CommonValidatorUtils::isEmailValidTemplate)
        .withMessage("The email is invalid value");

    // classId验证规则，指定到自定义分组
    ruleFor(myStudent::getClassId)
        .must(CommonValidatorUtils::isValidUUID)
        .withMessage("The getClassId value is invalid.")
        .configure(config -> config.AddGroup(ValidateClassIdGroup.class));
  }

}

验证时的用法：

MyValidator validator = new MyValidator();
MyStudent student = new MyStudent();

// 仅验证通用规则（跳过classId）
ValidationResult resultWithoutClassId = validator.validate(student);

// 验证通用规则 + classId规则
ValidationResult resultWithClassId = validator.validate(student, options -> {
    options.IncludeRuleSets(ValidateClassIdGroup.class);
});

内容的提问来源于stack exchange，提问作者Tina