Java tutorial
/* * The MIT License (MIT) * * Copyright (c) 2013 Brien L. Wheeler (brienwheeler@yahoo.com) * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.brienwheeler.svc.users.validation; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.util.StringUtils; import com.brienwheeler.lib.email.EmailAddress; import com.brienwheeler.svc.users.IUserEmailAddressService; public class EmailAddressNotExistValidator implements ConstraintValidator<EmailAddressNotExist, String>, ApplicationContextAware { private ApplicationContext applicationContext; private EmailAddressNotExist constraintAnnotation; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; } @Override public void initialize(EmailAddressNotExist constraintAnnotation) { this.constraintAnnotation = constraintAnnotation; } @Override public boolean isValid(String value, ConstraintValidatorContext context) { if (!StringUtils.hasText(value)) return !constraintAnnotation.failOnEmpty(); if (!EmailAddress.isValid(value)) return true; // invalid email addresses don't exist in the system IUserEmailAddressService userEmailAddressService = applicationContext .getBean(constraintAnnotation.userEmailAddressService(), IUserEmailAddressService.class); return userEmailAddressService.findByEmailAddress(new EmailAddress(value)) == null; } }