Java tutorial
/** * Copyright (C) 2016 Red Hat, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.syndesis.dao.validation; import java.util.Set; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import io.syndesis.dao.manager.DataManager; import io.syndesis.model.WithId; import io.syndesis.model.integration.Integration; import io.syndesis.model.integration.Integration.Status; import io.syndesis.model.validation.UniqueProperty; import org.hibernate.validator.constraintvalidation.HibernateConstraintValidatorContext; import org.springframework.beans.BeanWrapperImpl; import org.springframework.beans.PropertyAccessor; import org.springframework.beans.factory.annotation.Autowired; public class UniquePropertyValidator implements ConstraintValidator<UniqueProperty, WithId<?>> { @Autowired /* default */ DataManager dataManager; private String property; @Override public void initialize(final UniqueProperty uniqueProperty) { property = uniqueProperty.value(); } @Override public boolean isValid(final WithId<?> value, final ConstraintValidatorContext context) { if (value == null) { return true; } final PropertyAccessor bean = new BeanWrapperImpl(value); final String propertyValue = String.valueOf(bean.getPropertyValue(property)); @SuppressWarnings({ "rawtypes", "unchecked" }) final Class<WithId> modelClass = (Class) value.getKind().modelClass; @SuppressWarnings("unchecked") final Set<String> ids = dataManager.fetchIdsByPropertyValue(modelClass, property, propertyValue); final boolean isUnique = ids.isEmpty() || value.getId().map(id -> ids.contains(id)).orElse(false); if (!isUnique) { if (ids.stream().allMatch(id -> consideredValidByException(modelClass, id))) { return true; } context.disableDefaultConstraintViolation(); context.unwrap(HibernateConstraintValidatorContext.class) .addExpressionVariable("nonUnique", propertyValue) .buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate()) .addPropertyNode(property).addConstraintViolation(); } return isUnique; } /* default */ boolean consideredValidByException(@SuppressWarnings("rawtypes") final Class<WithId> modelClass, final String id) { @SuppressWarnings("unchecked") final WithId<?> modelInstance = dataManager.fetch(modelClass, id); // if we're looking at Integration then we need to make sure that // the Integration in question is not deleted if (modelInstance instanceof Integration) { return ((Integration) modelInstance).getCurrentStatus().map(Status.Deleted::equals).orElse(false); } return false; } }