org.argeo.cms/src/org/argeo/cms/acr/xml/XmlNormalizer.java

   1 package org.argeo.cms.acr.xml;
   2
   3 import java.io.ByteArrayInputStream;
   4 import java.io.IOException;
   5 import java.io.InputStream;
   6 import java.io.OutputStream;
   7 import java.nio.file.DirectoryStream;
   8 import java.nio.file.Files;
   9 import java.nio.file.Path;
  10 import java.nio.file.Paths;
  11
  12 import javax.xml.parsers.DocumentBuilder;
  13 import javax.xml.parsers.DocumentBuilderFactory;
  14 import javax.xml.parsers.ParserConfigurationException;
  15 import javax.xml.transform.OutputKeys;
  16 import javax.xml.transform.Result;
  17 import javax.xml.transform.Source;
  18 import javax.xml.transform.Transformer;
  19 import javax.xml.transform.TransformerException;
  20 import javax.xml.transform.TransformerFactory;
  21 import javax.xml.transform.TransformerFactoryConfigurationError;
  22 import javax.xml.transform.dom.DOMResult;
  23 import javax.xml.transform.dom.DOMSource;
  24 import javax.xml.transform.stream.StreamResult;
  25 import javax.xml.transform.stream.StreamSource;
  26
  27 import org.w3c.dom.DOMException;
  28 import org.w3c.dom.Document;
  29 import org.xml.sax.SAXException;
  30
  31 /**
  32  * Consistently normalises an XML in order to ease diff (typically in a
  33  * versioning system).
  34  */
  35 public class XmlNormalizer {
  36 //      private final static Logger logger = System.getLogger(XmlNormalizer.class.getName());
  37
  38         private DocumentBuilder documentBuilder;
  39         private TransformerFactory transformerFactory;
  40
  41         private DOMSource stripSpaceXsl;
  42
  43         public XmlNormalizer() {
  44                 this(2);
  45         }
  46
  47         public XmlNormalizer(int indent) {
  48                 try {
  49                         documentBuilder = DocumentBuilderFactory.newNSInstance().newDocumentBuilder();
  50                         transformerFactory = TransformerFactory.newInstance();
  51                         transformerFactory.setAttribute("indent-number", indent);
  52                         try (InputStream in = XmlNormalizer.class.getResourceAsStream("stripSpaces.xsl")) {
  53                                 DOMResult result = new DOMResult();
  54                                 transformerFactory.newTransformer().transform(new StreamSource(in), result);
  55                                 stripSpaceXsl = new DOMSource(result.getNode());
  56                         }
  57                 } catch (ParserConfigurationException | TransformerFactoryConfigurationError | TransformerException
  58                                 | IOException e) {
  59                         throw new IllegalStateException("Cannot initialise document builder and transformer", e);
  60                 }
  61         }
  62
  63         public void normalizeXmlFiles(DirectoryStream<Path> ds) throws IOException {
  64                 for (Path path : ds) {
  65                         normalizeXmlFile(path);
  66                 }
  67         }
  68
  69         public void normalizeXmlFile(Path path) throws IOException {
  70                 byte[] bytes = Files.readAllBytes(path);
  71                 try (ByteArrayInputStream in = new ByteArrayInputStream(bytes);
  72                                 OutputStream out = Files.newOutputStream(path)) {
  73                         normalizeAndIndent(in, out);
  74 //                      logger.log(Level.DEBUG, () -> "Normalized XML " + path);
  75                 }
  76         }
  77
  78         public void normalizeAndIndent(Source source, Result result) {
  79                 try {
  80                         Transformer transformer = transformerFactory.newTransformer(stripSpaceXsl);
  81                         transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
  82                         // transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
  83                         transformer.setOutputProperty(OutputKeys.INDENT, "yes");
  84
  85                         transformer.transform(source, result);
  86                 } catch (TransformerException e) {
  87                         throw new RuntimeException("Cannot strip space from " + source, e);
  88                 }
  89         }
  90
  91         public void normalizeAndIndent(InputStream in, OutputStream out) throws IOException {
  92                 try {
  93                         Document document = documentBuilder.parse(in);
  94
  95                         // clear whitespaces outside tags
  96                         document.normalize();
  97 //                      XPath xPath = XPathFactory.newInstance().newXPath();
  98 //                      NodeList nodeList = (NodeList) xPath.evaluate("//text()[normalize-space()='']", document,
  99 //                                      XPathConstants.NODESET);
 100 //
 101 //                      for (int i = 0; i < nodeList.getLength(); ++i) {
 102 //                              Node node = nodeList.item(i);
 103 //                              node.getParentNode().removeChild(node);
 104 //                      }
 105
 106                         normalizeAndIndent(new DOMSource(document), new StreamResult(out));
 107                 } catch (DOMException | IllegalArgumentException | SAXException | TransformerFactoryConfigurationError e) {
 108                         throw new RuntimeException("Cannot normalise and indent XML", e);
 109                 }
 110         }
 111
 112         public static void print(Source source, int indent) {
 113                 XmlNormalizer xmlNormalizer = new XmlNormalizer(indent);
 114                 xmlNormalizer.normalizeAndIndent(source, new StreamResult(System.out));
 115         }
 116
 117         public static void print(Source source) {
 118                 print(source, 2);
 119         }
 120
 121         public static void main(String[] args) throws IOException {
 122                 Path dir = Paths.get(args[0]);
 123                 XmlNormalizer xmlNormalizer = new XmlNormalizer();
 124                 DirectoryStream<Path> ds = Files.newDirectoryStream(dir, "*.svg");
 125                 xmlNormalizer.normalizeXmlFiles(ds);
 126
 127         }
 128 }