TurtleDB
A mini distributed database system
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00001 /*------------------------------------------------------------------------- 00002 Simple distributed database engine 00003 Copyright (C) 2012 Sylvain Hallé 00004 00005 This program is free software: you can redistribute it and/or modify 00006 it under the terms of the GNU General Public License as published by 00007 the Free Software Foundation, either version 3 of the License, or 00008 (at your option) any later version. 00009 00010 This program is distributed in the hope that it will be useful, 00011 but WITHOUT ANY WARRANTY; without even the implied warranty of 00012 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00013 GNU General Public License for more details. 00014 00015 You should have received a copy of the GNU General Public License 00016 along with this program. If not, see <http://www.gnu.org/licenses/>. 00017 -------------------------------------------------------------------------*/ 00018 package ca.uqac.dim.turtledb; 00019 00020 import java.io.StringWriter; 00021 import javax.xml.transform.*; 00022 import javax.xml.transform.dom.DOMSource; 00023 import javax.xml.transform.stream.StreamResult; 00024 import org.w3c.dom.*; 00025 00036 public class XmlQueryFormatter 00037 { 00043 public static Document toXmlDocument(Relation q) 00044 { 00045 XmlQueryVisitor v = new XmlQueryVisitor(); 00046 try 00047 { 00048 q.accept(v); 00049 } 00050 catch (EmptyQueryVisitor.VisitorException e) 00051 { 00052 e.printStackTrace(); 00053 } 00054 return v.getDocument(); 00055 } 00056 00063 public static String toXmlString(Relation q) 00064 { 00065 Document doc = toXmlDocument(q); 00066 try 00067 { 00068 DOMSource domSource = new DOMSource(doc); 00069 StringWriter writer = new StringWriter(); 00070 StreamResult result = new StreamResult(writer); 00071 TransformerFactory tf = TransformerFactory.newInstance(); 00072 tf.setAttribute("indent-number", new Integer(2)); 00073 Transformer transformer = tf.newTransformer(); 00074 transformer.setOutputProperty(OutputKeys.INDENT, "yes"); 00075 transformer.transform(domSource, result); 00076 return writer.toString(); 00077 } 00078 catch(TransformerException ex) 00079 { 00080 ex.printStackTrace(); 00081 return null; 00082 } 00083 } 00084 }