| 1 | // Jomic - a viewer for comic book archives. |
| 2 | // Copyright (C) 2004-2011 Thomas Aglassinger |
| 3 | // |
| 4 | // This program is free software: you can redistribute it and/or modify |
| 5 | // it under the terms of the GNU General Public License as published by |
| 6 | // the Free Software Foundation, either version 3 of the License, or |
| 7 | // (at your option) any later version. |
| 8 | // |
| 9 | // This program is distributed in the hope that it will be useful, |
| 10 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | // GNU General Public License for more details. |
| 13 | // |
| 14 | // You should have received a copy of the GNU General Public License |
| 15 | // along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | package net.sf.jomic.tools; |
| 17 | |
| 18 | import java.io.File; |
| 19 | import java.io.FileWriter; |
| 20 | import java.io.IOException; |
| 21 | import java.io.Writer; |
| 22 | |
| 23 | import javax.xml.parsers.DocumentBuilder; |
| 24 | import javax.xml.parsers.DocumentBuilderFactory; |
| 25 | import javax.xml.parsers.ParserConfigurationException; |
| 26 | |
| 27 | import org.apache.xml.serialize.OutputFormat; |
| 28 | import org.apache.xml.serialize.XMLSerializer; |
| 29 | import org.w3c.dom.Document; |
| 30 | import org.w3c.dom.Element; |
| 31 | import org.xml.sax.SAXException; |
| 32 | |
| 33 | /** |
| 34 | * Various utility methods to simplify processing XML data. |
| 35 | * |
| 36 | * @author Thomas Aglassinger |
| 37 | */ |
| 38 | public final class XmlTools |
| 39 | { |
| 40 | private static final int PRETTY_INDENT = 2; |
| 41 | private static final int PRETTY_LINE_WIDTH = 100; |
| 42 | private static XmlTools instance; |
| 43 | private DocumentBuilder documentBuilder; |
| 44 | private DocumentBuilderFactory documentBuilderFactory; |
| 45 | |
| 46 | private XmlTools() |
| 47 | throws ParserConfigurationException { |
| 48 | documentBuilderFactory = DocumentBuilderFactory.newInstance(); |
| 49 | documentBuilder = documentBuilderFactory.newDocumentBuilder(); |
| 50 | } |
| 51 | |
| 52 | public static synchronized XmlTools instance() { |
| 53 | if (instance == null) { |
| 54 | try { |
| 55 | instance = new XmlTools(); |
| 56 | } catch (Exception error) { |
| 57 | // Tunnel checked exception |
| 58 | LocaleTools localeTools = LocaleTools.instance(); |
| 59 | String message = localeTools.getMessage("errors.cannotSetUpXmlProcessing"); |
| 60 | IllegalStateException error2 = new IllegalStateException(message); |
| 61 | |
| 62 | error2.initCause(error); |
| 63 | throw error2; |
| 64 | } |
| 65 | } |
| 66 | return instance; |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Create new XML document. |
| 71 | * |
| 72 | * @param rootElementName name of the root element to add, or <code>null</code> if the |
| 73 | * document should not have any root just yet |
| 74 | */ |
| 75 | public Document createEmptyDocument(String rootElementName) { |
| 76 | Document result = documentBuilder.newDocument(); |
| 77 | |
| 78 | if (rootElementName != null) { |
| 79 | Element rootElement = result.createElement(rootElementName); |
| 80 | |
| 81 | result.appendChild(rootElement); |
| 82 | } |
| 83 | return result; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Pretty print <code>xmlFile</code>, replacing the original. |
| 88 | */ |
| 89 | public void prettyPrint(File xmlFile) |
| 90 | throws IOException, SAXException { |
| 91 | assert xmlFile != null; |
| 92 | Document document = readDocument(xmlFile); |
| 93 | Writer writer = new FileWriter(xmlFile); |
| 94 | |
| 95 | try { |
| 96 | prettyPrint(document, writer); |
| 97 | } finally { |
| 98 | writer.close(); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * Write <code>document</code> to <code>writer</code>. |
| 104 | */ |
| 105 | public void write(Document document, Writer writer) |
| 106 | throws IOException { |
| 107 | assert document != null; |
| 108 | assert writer != null; |
| 109 | OutputFormat format = new OutputFormat(document); |
| 110 | XMLSerializer serial = new XMLSerializer(writer, format); |
| 111 | |
| 112 | serial.asDOMSerializer(); |
| 113 | serial.serialize(document.getDocumentElement()); |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Pretty print <code>document</code> to <code>writer</code>. |
| 118 | */ |
| 119 | private void prettyPrint(Document document, Writer writer) |
| 120 | throws IOException { |
| 121 | OutputFormat format = new OutputFormat(document); |
| 122 | |
| 123 | format.setLineWidth(PRETTY_LINE_WIDTH); |
| 124 | format.setIndenting(true); |
| 125 | format.setIndent(PRETTY_INDENT); |
| 126 | |
| 127 | XMLSerializer serializer = new XMLSerializer(writer, format); |
| 128 | |
| 129 | serializer.serialize(document); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Read whole document from <code>xmlFile</code>. |
| 134 | */ |
| 135 | private Document readDocument(File xmlFile) |
| 136 | throws IOException, SAXException { |
| 137 | return documentBuilder.parse(xmlFile); |
| 138 | } |
| 139 | |
| 140 | } |