git-svn-id: https://joinup.ec.europa.eu/svn/moa-idspss/tags/1.4.5@1131 d688527b-c9ab-4aba-bd8d-4036d912da1d

1 files changed, 986 insertions, 0 deletions

diff --git a/common/src/main/java/at/gv/egovernment/moa/util/DOMUtils.java b/common/src/main/java/at/gv/egovernment/moa/util/DOMUtils.java
new file mode 100644
index 000000000..b403961d8
--- /dev/null
+++ b/common/src/main/java/at/gv/egovernment/moa/util/DOMUtils.java
@@ -0,0 +1,986 @@
+/*
+* Copyright 2003 Federal Chancellery Austria
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+package at.gv.egovernment.moa.util;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.Vector;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.w3c.dom.Attr;
+import org.w3c.dom.Document;
+import org.w3c.dom.DocumentFragment;
+import org.w3c.dom.Element;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+import org.apache.xerces.parsers.DOMParser;
+import org.apache.xerces.parsers.SAXParser;
+import org.apache.xerces.parsers.XMLGrammarPreparser;
+import org.apache.xerces.util.SymbolTable;
+import org.apache.xerces.util.XMLGrammarPoolImpl;
+import org.apache.xerces.xni.grammars.XMLGrammarDescription;
+import org.apache.xerces.xni.grammars.XMLGrammarPool;
+import org.apache.xerces.xni.parser.XMLInputSource;
+import org.xml.sax.EntityResolver;
+import org.xml.sax.ErrorHandler;
+import org.xml.sax.InputSource;
+import org.xml.sax.SAXException;
+
+
+import at.gv.egovernment.moa.logging.Logger;
+
+/**
+ * Various utility functions for handling XML DOM trees.
+ * 
+ * The parsing methods in this class make use of some features internal to the
+ * Xerces DOM parser, mainly for performance reasons. As soon as JAXP
+ * (currently at version 1.2) is better at schema handling, it should be used as
+ * the parser interface.
+ * 
+ * @author Patrick Peck
+ * @version $Id$
+ */
+public class DOMUtils {
+
+  /** Feature URI for namespace aware parsing. */
+  private static final String NAMESPACES_FEATURE =
+    "http://xml.org/sax/features/namespaces";
+  /** Feature URI for validating parsing. */
+  private static final String VALIDATION_FEATURE =
+    "http://xml.org/sax/features/validation";
+  /** Feature URI for schema validating parsing. */
+  private static final String SCHEMA_VALIDATION_FEATURE =
+    "http://apache.org/xml/features/validation/schema";
+  /** Feature URI for normalization of element/attribute values. */
+  private static final String NORMALIZED_VALUE_FEATURE =
+    "http://apache.org/xml/features/validation/schema/normalized-value";
+  /** Feature URI for parsing ignorable whitespace. */
+  private static final String INCLUDE_IGNORABLE_WHITESPACE_FEATURE =
+    "http://apache.org/xml/features/dom/include-ignorable-whitespace";
+  /** Feature URI for creating EntityReference nodes in the DOM tree. */
+  private static final String CREATE_ENTITY_REF_NODES_FEATURE =
+    "http://apache.org/xml/features/dom/create-entity-ref-nodes";
+  /** Property URI for providing external schema locations. */
+  private static final String EXTERNAL_SCHEMA_LOCATION_PROPERTY =
+    "http://apache.org/xml/properties/schema/external-schemaLocation";
+  /** Property URI for providing the external schema location for elements 
+   * without a namespace. */
+  private static final String EXTERNAL_NO_NAMESPACE_SCHEMA_LOCATION_PROPERTY =
+    "http://apache.org/xml/properties/schema/external-noNamespaceSchemaLocation";
+  /** Property URI for the Xerces grammar pool. */
+  private static final String GRAMMAR_POOL =
+    org.apache.xerces.impl.Constants.XERCES_PROPERTY_PREFIX
+      + org.apache.xerces.impl.Constants.XMLGRAMMAR_POOL_PROPERTY;
+  /** A prime number for initializing the symbol table. */
+  private static final int BIG_PRIME = 2039;
+  /** Symbol table for the grammar pool. */
+  private static SymbolTable symbolTable = new SymbolTable(BIG_PRIME);
+  /** Xerces schema grammar pool. */
+  private static XMLGrammarPool grammarPool = new XMLGrammarPoolImpl();
+  /** Set holding the NamespaceURIs of the grammarPool, to prevent multiple
+    * entries of same grammars to the pool */
+  private static Set grammarNamespaces; 
+
+  static {
+    grammarPool.lockPool();
+    grammarNamespaces = new HashSet();
+  }
+
+  /**
+   * Preparse a schema and add it to the schema pool.
+   * The method only adds the schema to the pool if a schema having the same
+   * <code>systemId</code> (namespace URI) is not already present in the pool.
+   * 
+   * @param inputStream An <code>InputStream</code> providing the contents of
+   * the schema.
+   * @param systemId The systemId (namespace URI) to use for the schema.
+   * @throws IOException An error occurred reading the schema.
+   */
+  public static void addSchemaToPool(InputStream inputStream, String systemId)
+    throws IOException {
+    XMLGrammarPreparser preparser;
+
+    if (!grammarNamespaces.contains(systemId)) { 
+
+      grammarNamespaces.add(systemId);
+    
+      // unlock the pool so that we can add another grammar
+      grammarPool.unlockPool();
+	
+      // prepare the preparser
+      preparser = new XMLGrammarPreparser(symbolTable);
+      preparser.registerPreparser(XMLGrammarDescription.XML_SCHEMA, null);
+      preparser.setProperty(GRAMMAR_POOL, grammarPool);
+      preparser.setFeature(NAMESPACES_FEATURE, true);
+      preparser.setFeature(VALIDATION_FEATURE, true);
+	
+      // add the grammar to the pool
+      preparser.preparseGrammar(
+      XMLGrammarDescription.XML_SCHEMA,
+        new XMLInputSource(null, systemId, null, inputStream, null));
+	
+      // lock the pool again so that schemas are not added automatically
+      grammarPool.lockPool();
+    }
+  }
+
+  /**
+   * Parse an XML document from an <code>InputStream</code>.
+   * 
+   * @param inputStream The <code>InputStream</code> containing the XML
+   * document.
+   * @param validating If <code>true</code>, parse validating.
+   * @param externalSchemaLocations A <code>String</code> containing namespace
+   * URI to schema location pairs, the same way it is accepted by the <code>xsi:
+   * schemaLocation</code> attribute. 
+   * @param externalNoNamespaceSchemaLocation The schema location of the
+   * schema for elements without a namespace, the same way it is accepted by the
+   * <code>xsi:noNamespaceSchemaLocation</code> attribute.
+   * @param entityResolver An <code>EntityResolver</code> to resolve external
+   * entities (schemas and DTDs). If <code>null</code>, it will not be set.
+   * @param errorHandler An <code>ErrorHandler</code> to decide what to do
+   * with parsing errors. If <code>null</code>, it will not be set.
+   * @return The parsed XML document as a DOM tree.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * parser.
+   */
+  public static Document parseDocument(
+    InputStream inputStream,
+    boolean validating,
+    String externalSchemaLocations,
+    String externalNoNamespaceSchemaLocation,
+    EntityResolver entityResolver,
+    ErrorHandler errorHandler)
+    throws  SAXException, IOException, ParserConfigurationException {
+
+    DOMParser parser;
+
+
+
+		//if Debug is enabled make a copy of inputStream to enable debug output in case of SAXException
+		byte buffer [] = null;
+		ByteArrayInputStream baStream = null;
+		if(true == Logger.isDebugEnabled()) {
+			int len = inputStream.available();
+			buffer = new byte[len];
+			inputStream.read(buffer);
+			baStream = new ByteArrayInputStream(buffer);
+		}	
+			
+    // create the DOM parser
+    if (symbolTable != null) {
+      parser = new DOMParser(symbolTable, grammarPool);
+    } else {
+      parser = new DOMParser();
+    }
+
+    // set parser features and properties
+    try {
+	    parser.setFeature(NAMESPACES_FEATURE, true);
+	    parser.setFeature(VALIDATION_FEATURE, validating);
+	    parser.setFeature(SCHEMA_VALIDATION_FEATURE, validating);
+	    parser.setFeature(NORMALIZED_VALUE_FEATURE, false);
+	    parser.setFeature(INCLUDE_IGNORABLE_WHITESPACE_FEATURE, true);
+	    parser.setFeature(CREATE_ENTITY_REF_NODES_FEATURE, false);
+	
+	    if (validating) {
+	      if (externalSchemaLocations != null) {
+	        parser.setProperty(
+	          EXTERNAL_SCHEMA_LOCATION_PROPERTY,
+	          externalSchemaLocations);
+	      }
+	      if (externalNoNamespaceSchemaLocation != null) {
+	        parser.setProperty(
+	          EXTERNAL_NO_NAMESPACE_SCHEMA_LOCATION_PROPERTY,
+	          externalNoNamespaceSchemaLocation);
+	      }
+	    }
+	
+	    // set entity resolver and error handler
+	    if (entityResolver != null) {
+	      parser.setEntityResolver(entityResolver);
+	    }
+	    if (errorHandler != null) {
+	      parser.setErrorHandler(errorHandler);
+	    }
+	
+	    // parse the document and return it
+	    // if debug is enabled: use copy of strem (baStream) else use orig stream
+	    if(null != baStream)
+	    	parser.parse(new InputSource(baStream));
+	    else 
+				parser.parse(new InputSource(inputStream));
+    } catch(SAXException e) {
+			if(true == Logger.isDebugEnabled() && null != buffer) {
+				String xmlContent = new String(buffer);
+				Logger.debug("SAXException in:\n" + xmlContent);				 
+			} 
+		  throw(e);
+    }
+
+    return parser.getDocument();
+  }
+
+  /**
+   * Parse an XML document from an <code>InputStream</code>.
+   * 
+   * It uses a <code>MOAEntityResolver</code> as the <code>EntityResolver</code>
+   * and a <code>MOAErrorHandler</code> as the <code>ErrorHandler</code>.
+   * 
+   * @param inputStream The <code>InputStream</code> containing the XML
+   * document.
+   * @param validating If <code>true</code>, parse validating.
+   * @param externalSchemaLocations A <code>String</code> containing namespace
+   * URI to schema location pairs, the same way it is accepted by the <code>xsi:
+   * schemaLocation</code> attribute. 
+   * @param externalNoNamespaceSchemaLocation The schema location of the
+   * schema for elements without a namespace, the same way it is accepted by the
+   * <code>xsi:noNamespaceSchemaLocation</code> attribute.
+   * @return The parsed XML document as a DOM tree.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * parser.
+   */
+  public static Document parseDocument(
+    InputStream inputStream,
+    boolean validating,
+    String externalSchemaLocations,
+    String externalNoNamespaceSchemaLocation)
+    throws SAXException, IOException, ParserConfigurationException {
+
+    return parseDocument(
+      inputStream,
+      validating,
+      externalSchemaLocations,
+      externalNoNamespaceSchemaLocation,
+      new MOAEntityResolver(),
+      new MOAErrorHandler());
+  }
+
+  /**
+   * Parse an XML document from a <code>String</code>.
+   * 
+   * It uses a <code>MOAEntityResolver</code> as the <code>EntityResolver</code>
+   * and a <code>MOAErrorHandler</code> as the <code>ErrorHandler</code>.
+   * 
+   * @param xmlString The <code>String</code> containing the XML document.
+   * @param encoding The encoding of the XML document.
+   * @param validating If <code>true</code>, parse validating.
+   * @param externalSchemaLocations A <code>String</code> containing namespace
+   * URI to schema location pairs, the same way it is accepted by the <code>xsi:
+   * schemaLocation</code> attribute. 
+   * @param externalNoNamespaceSchemaLocation The schema location of the
+   * schema for elements without a namespace, the same way it is accepted by the
+   * <code>xsi:noNamespaceSchemaLocation</code> attribute.
+   * @return The parsed XML document as a DOM tree.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * parser.
+   */
+  public static Document parseDocument(
+    String xmlString,
+    String encoding,
+    boolean validating,
+    String externalSchemaLocations,
+    String externalNoNamespaceSchemaLocation)
+    throws SAXException, IOException, ParserConfigurationException {
+
+    InputStream in = new ByteArrayInputStream(xmlString.getBytes(encoding));
+    return parseDocument(
+      in,
+      validating,
+      externalSchemaLocations,
+      externalNoNamespaceSchemaLocation);
+  }
+
+  /**
+   * Parse an UTF-8 encoded XML document from a <code>String</code>.
+   * 
+   * @param xmlString The <code>String</code> containing the XML document.
+   * @param validating If <code>true</code>, parse validating.
+   * @param externalSchemaLocations A <code>String</code> containing namespace
+   * URI to schema location pairs, the same way it is accepted by the <code>xsi:
+   * schemaLocation</code> attribute. 
+   * @param externalNoNamespaceSchemaLocation The schema location of the
+   * schema for elements without a namespace, the same way it is accepted by the
+   * <code>xsi:noNamespaceSchemaLocation</code> attribute.
+   * @return The parsed XML document as a DOM tree.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * parser.
+   */
+  public static Document parseDocument(
+    String xmlString,
+    boolean validating,
+    String externalSchemaLocations,
+    String externalNoNamespaceSchemaLocation)
+    throws SAXException, IOException, ParserConfigurationException {
+
+    return parseDocument(
+      xmlString,
+      "UTF-8",
+      validating,
+      externalSchemaLocations,
+      externalNoNamespaceSchemaLocation);
+  }
+
+  /**
+   * A convenience method to parse an XML document validating.
+   * 
+   * @param inputStream The <code>InputStream</code> containing the XML
+   * document.
+   * @return The root element of the parsed XML document.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * parser.
+   */
+  public static Element parseXmlValidating(InputStream inputStream)
+    throws ParserConfigurationException, SAXException, IOException {
+    return DOMUtils
+      .parseDocument(inputStream, true, Constants.ALL_SCHEMA_LOCATIONS, null)
+      .getDocumentElement();
+  }
+
+  /**
+   * Schema validate a given DOM element.
+   * 
+   * @param element The element to validate.
+   * @param externalSchemaLocations A <code>String</code> containing namespace
+   * URI to schema location pairs, the same way it is accepted by the <code>xsi:
+   * schemaLocation</code> attribute. 
+   * @param externalNoNamespaceSchemaLocation The schema location of the
+   * schema for elements without a namespace, the same way it is accepted by the
+   * <code>xsi:noNamespaceSchemaLocation</code> attribute.
+   * @return <code>true</code>, if the <code>element</code> validates against
+   * the schemas declared in it.
+   * @throws SAXException An error occurred parsing the document.
+   * @throws IOException An error occurred reading the document from its
+   * serialized representation.
+   * @throws ParserConfigurationException An error occurred configuring the XML
+   * @throws TransformerException An error occurred serializing the element.
+   */
+  public static boolean validateElement(
+    Element element,
+    String externalSchemaLocations,
+    String externalNoNamespaceSchemaLocation)
+    throws
+      ParserConfigurationException,
+      IOException,
+      SAXException,
+      TransformerException {
+
+    byte[] docBytes;
+    SAXParser parser;
+
+    // create the SAX parser
+    if (symbolTable != null) {
+      parser = new SAXParser(symbolTable, grammarPool);
+    } else {
+      parser = new SAXParser();
+    }
+
+    // serialize the document
+    docBytes = serializeNode(element, "UTF-8");
+
+    // set up parser features and attributes
+    parser.setFeature(NAMESPACES_FEATURE, true);
+    parser.setFeature(VALIDATION_FEATURE, true);
+    parser.setFeature(SCHEMA_VALIDATION_FEATURE, true);
+    if (externalSchemaLocations != null) {
+      parser.setProperty(
+        EXTERNAL_SCHEMA_LOCATION_PROPERTY,
+        externalSchemaLocations);
+    }
+    if (externalNoNamespaceSchemaLocation != null) {
+      parser.setProperty(
+        EXTERNAL_NO_NAMESPACE_SCHEMA_LOCATION_PROPERTY,
+        "externalNoNamespaceSchemaLocation");
+    }
+
+    // set up entity resolver and error handler
+    parser.setEntityResolver(new MOAEntityResolver());
+    parser.setErrorHandler(new MOAErrorHandler());
+
+    // parse validating
+    parser.parse(new InputSource(new ByteArrayInputStream(docBytes)));
+    return true;
+  }
+
+  /**
+   * Serialize the given DOM node.
+   * 
+   * The node will be serialized using the UTF-8 encoding.
+   * 
+   * @param node The node to serialize.
+   * @return String The <code>String</code> representation of the given DOM
+   * node.
+   * @throws TransformerException An error occurred transforming the
+   * node to a <code>String</code>.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static String serializeNode(Node node)
+    throws TransformerException, IOException {
+    return new String(serializeNode(node, "UTF-8", false), "UTF-8");
+  }
+
+
+  /**
+   * Serialize the given DOM node.
+   * 
+   * The node will be serialized using the UTF-8 encoding.
+   * 
+   * @param node The node to serialize.
+   * @param omitXmlDeclaration The boolean value for omitting the XML Declaration.
+   * @return String The <code>String</code> representation of the given DOM
+   * node.
+   * @throws TransformerException An error occurred transforming the
+   * node to a <code>String</code>.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static String serializeNode(Node node, boolean omitXmlDeclaration)
+    throws TransformerException, IOException {
+    return new String(serializeNode(node, "UTF-8", omitXmlDeclaration), "UTF-8");
+  }
+
+  /**
+   * Serialize the given DOM node.
+   * 
+   * The node will be serialized using the UTF-8 encoding.
+   * 
+   * @param node The node to serialize.
+   * @param omitXmlDeclaration The boolean value for omitting the XML Declaration.
+   * @param lineSeperator Sets the line seperator String of the parser
+   * @return String The <code>String</code> representation of the given DOM
+   * node.
+   * @throws TransformerException An error occurred transforming the
+   * node to a <code>String</code>.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static String serializeNode(Node node, boolean omitXmlDeclaration, String lineSeperator)
+    throws TransformerException, IOException {
+    return new String(serializeNode(node, "UTF-8", omitXmlDeclaration, lineSeperator), "UTF-8");
+  }
+  
+  /**
+   * Serialize the given DOM node to a byte array.
+   * 
+   * @param node The node to serialize.
+   * @param xmlEncoding The XML encoding to use.
+   * @return The serialized node, as a byte array. Using a compatible encoding
+   * this can easily be converted into a <code>String</code>.
+   * @throws TransformerException An error occurred transforming the node to a 
+   * byte array.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static byte[] serializeNode(Node node, String xmlEncoding)
+  throws TransformerException, IOException {
+    return serializeNode(node, xmlEncoding, false);
+  }
+  
+  /**
+   * Serialize the given DOM node to a byte array.
+   * 
+   * @param node The node to serialize.
+   * @param xmlEncoding The XML encoding to use.
+   * @param omitDeclaration The boolean value for omitting the XML Declaration.
+   * @return The serialized node, as a byte array. Using a compatible encoding
+   * this can easily be converted into a <code>String</code>.
+   * @throws TransformerException An error occurred transforming the node to a 
+   * byte array.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static byte[] serializeNode(Node node, String xmlEncoding, boolean omitDeclaration)
+    throws TransformerException, IOException {
+    return serializeNode(node, xmlEncoding, omitDeclaration, null);
+  }
+
+
+  /**
+   * Serialize the given DOM node to a byte array.
+   * 
+   * @param node The node to serialize.
+   * @param xmlEncoding The XML encoding to use.
+   * @param omitDeclaration The boolean value for omitting the XML Declaration.
+   * @param lineSeperator Sets the line seperator String of the parser
+   * @return The serialized node, as a byte array. Using a compatible encoding
+   * this can easily be converted into a <code>String</code>.
+   * @throws TransformerException An error occurred transforming the node to a 
+   * byte array.
+   * @throws IOException An IO error occurred writing the node to a byte array.
+   */
+  public static byte[] serializeNode(Node node, String xmlEncoding, boolean omitDeclaration, String lineSeperator)
+    throws TransformerException, IOException {
+
+    TransformerFactory transformerFactory = TransformerFactory.newInstance();
+    Transformer transformer = transformerFactory.newTransformer();
+    ByteArrayOutputStream bos = new ByteArrayOutputStream(16384);
+
+    transformer.setOutputProperty(OutputKeys.METHOD, "xml");
+    transformer.setOutputProperty(OutputKeys.ENCODING, xmlEncoding);
+    String omit = omitDeclaration ? "yes" : "no";
+    transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, omit);
+    if (null!=lineSeperator) {
+      transformer.setOutputProperty("{http://xml.apache.org/xalan}line-separator", lineSeperator);//does not work for xalan <= 2.5.1
+    }
+    transformer.transform(new DOMSource(node), new StreamResult(bos));
+
+    bos.flush();
+    bos.close();
+
+    return bos.toByteArray();
+  }
+
+  /**
+    * Return the text that a node contains. 
+    * 
+    * This routine:
+    * <ul>
+    * <li>Ignores comments and processing instructions.</li>
+    * <li>Concatenates TEXT nodes, CDATA nodes, and the results recursively
+    * processing EntityRef nodes.</li>
+    * <li>Ignores any element nodes in the sublist. (Other possible options are
+    * to recurse into element sublists or throw an exception.)</li>
+    * </ul>
+    * 
+    * @param node A DOM node from which to extract text.
+    * @return A String representing its contents.
+    */
+  public static String getText(Node node) {
+    if (!node.hasChildNodes()) {
+      return "";
+    }
+
+    StringBuffer result = new StringBuffer();
+    NodeList list = node.getChildNodes();
+
+    for (int i = 0; i < list.getLength(); i++) {
+      Node subnode = list.item(i);
+      if (subnode.getNodeType() == Node.TEXT_NODE) {
+        result.append(subnode.getNodeValue());
+      } else if (subnode.getNodeType() == Node.CDATA_SECTION_NODE) {
+        result.append(subnode.getNodeValue());
+      } else if (subnode.getNodeType() == Node.ENTITY_REFERENCE_NODE) {
+        // Recurse into the subtree for text
+        // (and ignore comments)
+        result.append(getText(subnode));
+      }
+    }
+    return result.toString();
+  }
+
+  /**
+   * Build the namespace prefix to namespace URL mapping in effect for a given
+   * node.
+   * 
+   * @param node The context node for which build the map.
+   * @return The namespace prefix to namespace URL mapping (
+   * a <code>String</code> value to <code>String</code> value mapping).
+   */
+  public static Map getNamespaceDeclarations(Node node) {
+    Map nsDecls = new HashMap();
+    int i;
+
+    do {
+      if (node.hasAttributes()) {
+        NamedNodeMap attrs = node.getAttributes();
+
+        for (i = 0; i < attrs.getLength(); i++) {
+          Attr attr = (Attr) attrs.item(i);
+
+          // add prefix mapping if none exists
+          if ("xmlns".equals(attr.getPrefix())
+            || "xmlns".equals(attr.getName())) {
+
+            String nsPrefix =
+              attr.getPrefix() != null ? attr.getLocalName() : "";
+
+            if (nsDecls.get(nsPrefix) == null) {
+              nsDecls.put(nsPrefix, attr.getValue());
+            }
+          }
+        }
+      }
+    } while ((node = node.getParentNode()) != null);
+
+    return nsDecls;
+  }
+
+  /**
+   * Add all namespace declarations declared in the parent(s) of a given
+   * element and used in the subtree of the given element to the given element.  
+   * 
+   * @param context The element to which to add the namespaces.
+   */
+  public static void localizeNamespaceDeclarations(Element context) {
+    Node parent = context.getParentNode();
+
+    if (parent != null) {
+      Map namespaces = getNamespaceDeclarations(context.getParentNode());
+      Set nsUris = collectNamespaceURIs(context);
+      Iterator iter;
+
+      for (iter = namespaces.entrySet().iterator(); iter.hasNext();) {
+        Map.Entry e = (Map.Entry) iter.next();
+
+        if (nsUris.contains(e.getValue())) {
+          String prefix = (String) e.getKey();
+          String nsUri = (String) e.getValue();
+          String nsAttrName = "".equals(prefix) ? "xmlns" : "xmlns:" + prefix;
+
+          context.setAttributeNS(Constants.XMLNS_NS_URI, nsAttrName, nsUri);
+        }
+      }
+    }
+  }
+
+  /**
+   * Collect all the namespace URIs used in the subtree of a given element.
+   * 
+   * @param context The element that should be searched for namespace URIs.
+   * @return All namespace URIs used in the subtree of <code>context</code>,
+   * including the ones used in <code>context</code> itself.
+   */
+  public static Set collectNamespaceURIs(Element context) {
+    Set result = new HashSet();
+
+    collectNamespaceURIsImpl(context, result);
+    return result;
+  }
+
+  /**
+   * A recursive method to do the work of <code>collectNamespaceURIs</code>.
+   * 
+   * @param context The context element to evaluate.
+   * @param result The result, passed as a parameter to avoid unnecessary
+   * instantiations of <code>Set</code>.
+   */
+  private static void collectNamespaceURIsImpl(Element context, Set result) {
+    NamedNodeMap attrs = context.getAttributes();
+    NodeList childNodes = context.getChildNodes();
+    String nsUri;
+    int i;
+
+    // add the namespace of the context element
+    nsUri = context.getNamespaceURI();
+    if (nsUri != null && nsUri != Constants.XMLNS_NS_URI) {
+      result.add(nsUri);
+    }
+
+    // add all namespace URIs from attributes
+    for (i = 0; i < attrs.getLength(); i++) {
+      nsUri = attrs.item(i).getNamespaceURI();
+      if (nsUri != null && nsUri != Constants.XMLNS_NS_URI) {
+        result.add(nsUri);
+      }
+    }
+
+    // add all namespaces from subelements
+    for (i = 0; i < childNodes.getLength(); i++) {
+      Node node = childNodes.item(i);
+
+      if (node.getNodeType() == Node.ELEMENT_NODE) {
+        collectNamespaceURIsImpl((Element) node, result);
+      }
+    }
+  }
+
+  /**
+   * Check, that each attribute node in the given <code>NodeList</code> has its
+   * parent in the <code>NodeList</code> as well.
+   * 
+   * @param nodes The <code>NodeList</code> to check.
+   * @return <code>true</code>, if each attribute node in <code>nodes</code>
+   * has its parent in <code>nodes</code> as well.
+   */
+  public static boolean checkAttributeParentsInNodeList(NodeList nodes) {
+    Set nodeSet = new HashSet();
+    int i;
+
+    // put the nodes into the nodeSet
+    for (i = 0; i < nodes.getLength(); i++) {
+      nodeSet.add(nodes.item(i));
+    }
+
+    // check that each attribute node's parent is in the node list
+    for (i = 0; i < nodes.getLength(); i++) {
+      Node n = nodes.item(i);
+
+      if (n.getNodeType() == Node.ATTRIBUTE_NODE) {
+        Attr attr = (Attr) n;
+        Element owner = attr.getOwnerElement();
+
+        if (owner == null) {
+          if (!isNamespaceDeclaration(attr)) {
+            return false;
+          }
+        }
+
+        if (!nodeSet.contains(owner) && !isNamespaceDeclaration(attr)) {
+          return false;
+        }
+      }
+    }
+
+    return true;
+  }
+
+  /**
+   * Convert an unstructured <code>NodeList</code> into a 
+   * <code>DocumentFragment</code>.
+   *
+   * @param nodeList Contains the node list to be converted into a DOM 
+   * DocumentFragment.
+   * @return the resulting DocumentFragment. The DocumentFragment will be 
+   * backed by a new DOM Document, i.e. all noded of the node list will be 
+   * cloned.
+   * @throws ParserConfigurationException An error occurred creating the
+   * DocumentFragment.
+   * @precondition The nodes in the node list appear in document order
+   * @precondition for each Attr node in the node list, the owning Element is 
+   * in the node list as well.
+   * @precondition each Element or Attr node in the node list is namespace 
+   * aware.
+   */
+  public static DocumentFragment nodeList2DocumentFragment(NodeList nodeList)
+    throws ParserConfigurationException {
+
+    DocumentBuilder builder =
+      DocumentBuilderFactory.newInstance().newDocumentBuilder();
+    Document doc = builder.newDocument();
+    DocumentFragment result = doc.createDocumentFragment();
+
+    if (null == nodeList || nodeList.getLength() == 0) {
+      return result;
+    }
+
+    int currPos = 0;
+    currPos =
+      nodeList2DocumentFragment(nodeList, currPos, result, null, null) + 1;
+
+    while (currPos < nodeList.getLength()) {
+      currPos =
+        nodeList2DocumentFragment(nodeList, currPos, result, null, null) + 1;
+    }
+    return result;
+  }
+
+  /**
+   * Helper method for the <code>nodeList2DocumentFragment</code>.
+   * 
+   * @param nodeList The <code>NodeList</code> to convert.
+   * @param currPos The current position in the <code>nodeList</code>.
+   * @param result The resulting <code>DocumentFragment</code>.
+   * @param currOrgElem The current original element.
+   * @param currClonedElem The current cloned element.
+   * @return The current position.
+   */
+  private static int nodeList2DocumentFragment(
+    NodeList nodeList,
+    int currPos,
+    DocumentFragment result,
+    Element currOrgElem,
+    Element currClonedElem) {
+
+    while (currPos < nodeList.getLength()) {
+      Node currentNode = nodeList.item(currPos);
+      switch (currentNode.getNodeType()) {
+        case Node.COMMENT_NODE :
+        case Node.PROCESSING_INSTRUCTION_NODE :
+        case Node.TEXT_NODE :
+          {
+            // Append current node either to resulting DocumentFragment or to 
+            // current cloned Element
+            if (null == currClonedElem) {
+              result.appendChild(
+                result.getOwnerDocument().importNode(currentNode, false));
+            } else {
+              // Stop processing if current Node is not a descendant of 
+              // current Element
+              if (!isAncestor(currOrgElem, currentNode)) {
+                return --currPos;
+              }
+
+              currClonedElem.appendChild(
+                result.getOwnerDocument().importNode(currentNode, false));
+            }
+            break;
+          }
+
+        case Node.ELEMENT_NODE :
+          {
+            Element nextCurrOrgElem = (Element) currentNode;
+            Element nextCurrClonedElem =
+              result.getOwnerDocument().createElementNS(
+                nextCurrOrgElem.getNamespaceURI(),
+                nextCurrOrgElem.getNodeName());
+
+            // Append current Node either to resulting DocumentFragment or to 
+            // current cloned Element
+            if (null == currClonedElem) {
+              result.appendChild(nextCurrClonedElem);
+              currOrgElem = nextCurrOrgElem;
+              currClonedElem = nextCurrClonedElem;
+            } else {
+              // Stop processing if current Node is not a descendant of
+              // current Element
+              if (!isAncestor(currOrgElem, currentNode)) {
+                return --currPos;
+              }
+
+              currClonedElem.appendChild(nextCurrClonedElem);
+            }
+
+            // Process current Node (of type Element) recursively
+            currPos =
+              nodeList2DocumentFragment(
+                nodeList,
+                ++currPos,
+                result,
+                nextCurrOrgElem,
+                nextCurrClonedElem);
+
+            break;
+          }
+
+        case Node.ATTRIBUTE_NODE :
+          {
+            Attr currAttr = (Attr) currentNode;
+
+            // GK 20030411: Hack to overcome problems with IAIK IXSIL
+            if (currAttr.getOwnerElement() == null)
+              break;
+            if (currClonedElem == null)
+              break;
+
+            // currClonedElem must be the owner Element of currAttr if 
+            // preconditions are met
+            currClonedElem.setAttributeNS(
+              currAttr.getNamespaceURI(),
+              currAttr.getNodeName(),
+              currAttr.getValue());
+            break;
+          }
+
+        default :
+          {
+            // All other nodes will be ignored
+          }
+      }
+
+      currPos++;
+    }
+
+    return currPos;
+  }
+
+  /**
+   * Check, if the given attribute is a namespace declaration.
+   * 
+   * @param attr The attribute to check.
+   * @return <code>true</code>, if the attribute is a namespace declaration,
+   * <code>false</code> otherwise.
+   */
+  private static boolean isNamespaceDeclaration(Attr attr) {
+    return Constants.XMLNS_NS_URI.equals(attr.getNamespaceURI());
+  }
+
+  /**
+   * Check, if a given DOM element is an ancestor of a given node.
+   * 
+   * @param candAnc The DOM element to check for being the ancestor.
+   * @param cand The node to check for being the child.
+   * @return <code>true</code>, if <code>candAnc</code> is an (indirect) 
+   * ancestor of <code>cand</code>; <code>false</code> otherwise.
+   */
+  public static boolean isAncestor(Element candAnc, Node cand) {
+    Node currPar = cand.getParentNode();
+
+    while (currPar != null) {
+      if (candAnc == currPar)
+        return true;
+      currPar = currPar.getParentNode();
+    }
+    return false;
+  }
+  
+  /**
+   * Selects the (first) element from a node list and returns it.
+   * 
+   * @param nl  The NodeList to get the element from.
+   * @return    The (first) element included in the node list or <code>null</code>
+   *            if the node list is <code>null</code> or empty or no element is
+   *            included in the list.
+   */
+  public static Element getElementFromNodeList (NodeList nl) {
+    if ((nl == null) || (nl.getLength() == 0)) {
+      return null;
+    }
+    for (int i=0; i<nl.getLength(); i++) {
+      Node node = nl.item(i);
+      if (node.getNodeType() == Node.ELEMENT_NODE)  {
+        return  (Element)node;
+      }
+    }
+    return null;
+  }
+  
+  /**
+   * Returns all child elements of the given element.
+   * 
+   * @param parent  The element to get the child elements from.
+   * 
+   * @return A list including all child elements of the given element.
+   *         Maybe empty if the parent element has no child elements.
+   */
+  public static List getChildElements (Element parent) {
+    Vector v = new Vector();
+    NodeList nl = parent.getChildNodes();
+    int length = nl.getLength();
+    for (int i=0; i < length; i++) {
+      Node node = nl.item(i);
+      if (node.getNodeType() == Node.ELEMENT_NODE) {
+        v.add((Element)node);
+      }
+    }
+    return v;
+  }
+
+}