001/* 002 * (C) Copyright 2006-2007 Nuxeo SAS (http://nuxeo.com/) and contributors. 003 * 004 * All rights reserved. This program and the accompanying materials 005 * are made available under the terms of the GNU Lesser General Public License 006 * (LGPL) version 2.1 which accompanies this distribution, and is available at 007 * http://www.gnu.org/licenses/lgpl.html 008 * 009 * This library is distributed in the hope that it will be useful, 010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 012 * Lesser General Public License for more details. 013 * 014 * Contributors: 015 * <a href="mailto:at@nuxeo.com">Anahide Tchertchian</a> 016 * 017 * $Id: IORelationGraphHelper.java 25081 2007-09-18 14:57:22Z atchertchian $ 018 */ 019 020package org.nuxeo.ecm.platform.relations.io; 021 022import java.io.InputStream; 023import java.io.OutputStream; 024import java.util.List; 025import java.util.Map; 026 027import org.nuxeo.ecm.platform.relations.api.Graph; 028import org.nuxeo.ecm.platform.relations.api.Statement; 029import org.nuxeo.ecm.platform.relations.jena.JenaGraph; 030 031/** 032 * Relation graph importer/exporter. 033 * <p> 034 * relies on Jena memory graphs to perform serialization and deserialization of memory graphs. 035 * 036 * @author <a href="mailto:at@nuxeo.com">Anahide Tchertchian</a> 037 */ 038public class IORelationGraphHelper { 039 040 protected final Map<String, String> namespaces; 041 042 protected List<Statement> statements; 043 044 public IORelationGraphHelper(Map<String, String> namespaces, List<Statement> statements) { 045 this.namespaces = namespaces; 046 this.statements = statements; 047 } 048 049 public List<Statement> getStatements() { 050 return statements; 051 } 052 053 protected Graph createMemoryGraph() { 054 JenaGraph graph = new JenaGraph(); 055 graph.setNamespaces(namespaces); 056 return graph; 057 } 058 059 public void write(OutputStream out) { 060 Graph graph = createMemoryGraph(); 061 if (statements != null) { 062 graph.add(statements); 063 } 064 graph.write(out, null, null); 065 } 066 067 public void read(InputStream in) { 068 Graph graph = createMemoryGraph(); 069 if (statements != null) { 070 graph.add(statements); 071 } 072 graph.read(in, null, null); 073 // update current statements with new ones 074 statements = graph.getStatements(); 075 } 076 077 public Graph getGraph() { 078 Graph graph = createMemoryGraph(); 079 if (statements != null) { 080 graph.add(statements); 081 } 082 return graph; 083 } 084 085}