/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.ambari.view; import java.util.Collection; /** * View data store. */ public interface DataStore { /** * Save the given entity to persistent storage. The entity must be declared as an * {@code <entity>} in the {@code <persistence>} element of the view.xml. * * @param entity the entity to be persisted. * * @throws PersistenceException thrown if the given entity can not be persisted */ public void store(Object entity) throws PersistenceException; /** * Remove the given entity from persistent storage. * * @param entity the entity to be removed. * * @throws PersistenceException thrown if the given entity can not be removed */ public void remove(Object entity) throws PersistenceException; /** * Find the entity of the given class type that is uniquely identified by the * given primary key. * * @param clazz the entity class * @param primaryKey the primary key * @param <T> the entity type * * @return the entity; null if the entity can't be found * * @throws PersistenceException thrown if an error occurs trying to find the entity */ public <T> T find(Class<T> clazz, Object primaryKey) throws PersistenceException; /** * Find all the entities for the given where clause. Specifying null for the where * clause should return all entities of the given class type. * * @param clazz the entity class * @param whereClause the where clause; may be null * @param <T> the entity type * * @return all of the entities for the given where clause; empty collection if no * entities can be found * * @throws PersistenceException */ public <T> Collection<T> findAll(Class<T> clazz, String whereClause) throws PersistenceException; }