Java Spring Boot应用程序中的自定义constraintvalidator不会被调用

我正在try 为某些类创建自定义验证器 我定义的约束如下(根据不同的样本，例如从here)

@Target({ TYPE, ANNOTATION_TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = { MyClassValidator.class })
@Documented
public @interface MyClassValid {
    String message() default "The password2 does not comply with the rules";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

然后我创建了相应的验证器:

 public class MyClassValidator implements ConstraintValidator<MyClassValid, ChangePasswordBody> {
        @Override
        public boolean isValid(ChangePasswordBody value, ConstraintValidatorContext context) {
            
/*This check only for sample . Ot can be replaced by other logic*/
if (value.getNewPassword().length() > 2 ) {
                return true;
            }
            return false;
        }
    }

要验证的类:

@MyClassValid
public class ChangePasswordBody {
    private String oldPassword;
    private String newPassword;

    public String getOldPassword() {
        return oldPassword;
    }

    public void setOldPassword(String oldPassword) {
        this.oldPassword = oldPassword;
    }

    public String getNewPassword() {
        return newPassword;
    }
    
    public void setNewPassword(String newPassword) {
        this.newPassword = newPassword;
    }
}

这是使用ChangePasswordBody的代码

private static void testChangePwd(ApplicationContext applicationContext) {
    //...
    ChangePasswordBody pwdBody = new ChangePasswordBody();
    isValidPassword(pwdBody);
    //...
}
private static void isValidPassword(ChangePasswordBody pwdBody) {
    pwdBody.setNewPassword("l"); 
}

我看到在执行testChangePwd方法时-MyClassValidator.isValid没有被调用.代码中有什么遗漏/错误吗？提前谢谢你