src/de/j32/util/XmlUtil.java

   1 package de.j32.util;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.io.StringReader;
   6 import java.util.Iterator;
   7
   8 import javax.xml.parsers.DocumentBuilder;
   9 import javax.xml.parsers.DocumentBuilderFactory;
  10 import javax.xml.parsers.ParserConfigurationException;
  11
  12 import org.w3c.dom.Document;
  13 import org.w3c.dom.Node;
  14 import org.w3c.dom.NodeList;
  15 import org.xml.sax.EntityResolver;
  16 import org.xml.sax.InputSource;
  17 import org.xml.sax.SAXException;
  18
  19 public class XmlUtil
  20 {
  21     public static Document parse(InputStream is) throws SAXException, IOException
  22     {
  23         try {
  24             DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  25             factory.setValidating(false);
  26             factory.setExpandEntityReferences(false);
  27             DocumentBuilder builder = factory.newDocumentBuilder();
  28             builder.setEntityResolver(new EntityResolver() {
  29                 public InputSource resolveEntity(String publicId, String systemId)
  30                         throws SAXException, IOException
  31                 {
  32                     return new InputSource(new StringReader(""));
  33                 }
  34             });
  35             return builder.parse(is);
  36         }
  37         catch (ParserConfigurationException e) {
  38             throw new AssertionError("SAX/DOM parser configuration error");
  39         }
  40     }
  41
  42     public static <E extends Node> Iterable<E> iterate(final NodeList nodes, final Class<E> type)
  43     {
  44         return new Iterable<E>() {
  45             public Iterator<E> iterator()
  46             {
  47                 return new NodeListIterator<E>(nodes, type);
  48             }
  49         };
  50     }
  51
  52     static class NodeListIterator<E extends Node> implements Iterator<E>
  53     {
  54         Class<E> nodeType_;
  55         NodeList nodes_;
  56         int i_ = 0;
  57         E next_;
  58
  59         public NodeListIterator(NodeList nodes, Class<E> nodeType)
  60         {
  61             nodes_ = nodes;
  62             nodeType_ = nodeType;
  63             advance();
  64         }
  65
  66         @Override
  67         public boolean hasNext()
  68         {
  69             return next_ != null;
  70         }
  71
  72         @Override
  73         public E next()
  74         {
  75             E rv = next_;
  76             advance();
  77             return rv;
  78         }
  79
  80         @Override
  81         public void remove()
  82         {
  83             throw new UnsupportedOperationException();
  84         }
  85
  86         @SuppressWarnings("unchecked")
  87         void advance()
  88         {
  89             while (i_ < nodes_.getLength()) {
  90                 Node n = nodes_.item(i_);
  91                 ++i_;
  92                 if (nodeType_.isInstance(n)) {
  93                     next_ = (E) n;
  94                     return;
  95                 }
  96             }
  97             next_ = null;
  98         }
  99     }
 100 }