001 /* 002 * JBoss DNA (http://www.jboss.org/dna) 003 * See the COPYRIGHT.txt file distributed with this work for information 004 * regarding copyright ownership. Some portions may be licensed 005 * to Red Hat, Inc. under one or more contributor license agreements. 006 * See the AUTHORS.txt file in the distribution for a full listing of 007 * individual contributors. 008 * 009 * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA 010 * is licensed to you under the terms of the GNU Lesser General Public License as 011 * published by the Free Software Foundation; either version 2.1 of 012 * the License, or (at your option) any later version. 013 * 014 * JBoss DNA is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 017 * Lesser General Public License for more details. 018 * 019 * You should have received a copy of the GNU Lesser General Public 020 * License along with this software; if not, write to the Free 021 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 022 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 023 */ 024 package org.jboss.dna.connector.store.jpa.util; 025 026 import java.util.HashMap; 027 import java.util.Map; 028 import javax.persistence.EntityManager; 029 import net.jcip.annotations.NotThreadSafe; 030 import org.jboss.dna.connector.store.jpa.model.common.NamespaceEntity; 031 032 /** 033 * @author Randall Hauch 034 */ 035 @NotThreadSafe 036 public class Namespaces { 037 038 private final EntityManager entityManager; 039 private final Map<String, NamespaceEntity> cache = new HashMap<String, NamespaceEntity>(); 040 041 public Namespaces( EntityManager manager ) { 042 this.entityManager = manager; 043 } 044 045 public NamespaceEntity get( String namespaceUri, 046 boolean createIfRequired ) { 047 NamespaceEntity entity = cache.get(namespaceUri); 048 if (entity == null) { 049 entity = NamespaceEntity.findByUri(entityManager, namespaceUri, createIfRequired); 050 if (entity != null) { 051 cache.put(namespaceUri, entity); 052 } 053 } 054 return entity; 055 } 056 }