src/main/java/org/jboss/util/xml/catalog/readers/OASISXMLCatalogReader.java
public void startElement (String namespaceURI,
			    String localName,
			    String qName,
			    Attributes atts)
    throws SAXException {

    int entryType = -1;
    Vector entryArgs = new Vector();

    namespaceStack.push(namespaceURI);

    boolean inExtension = inExtensionNamespace();

    if (namespaceURI != null && namespaceName.equals(namespaceURI)
	&& !inExtension) {
      // This is an XML Catalog entry

      if (atts.getValue("xml:base") != null) {
	String baseURI = atts.getValue("xml:base");
	entryType = Catalog.BASE;
	entryArgs.add(baseURI);
	baseURIStack.push(baseURI);

	debug.message(4, "xml:base", baseURI);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (base)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	baseURIStack.push(baseURIStack.peek());
      }

      if ((localName.equals("catalog") || localName.equals("group"))
	  && atts.getValue("prefer") != null) {
	String override = atts.getValue("prefer");

	if (override.equals("public")) {
	  override = "yes";
	} else if (override.equals("system")) {
	  override = "no";
	} else {
	  debug.message(1,
			"Invalid prefer: must be 'system' or 'public'",
			localName);
	  override = catalog.getDefaultOverride();
	}

	entryType = Catalog.OVERRIDE;
	entryArgs.add(override);
	overrideStack.push(override);

	debug.message(4, "override", override);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (override)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	overrideStack.push(overrideStack.peek());
      }

      if (localName.equals("delegatePublic")) {
	if (checkAttributes(atts, "publicIdStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_PUBLIC;
	  entryArgs.add(atts.getValue("publicIdStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegatePublic",
			PublicId.normalize(atts.getValue("publicIdStartString")),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("delegateSystem")) {
	if (checkAttributes(atts, "systemIdStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_SYSTEM;
	  entryArgs.add(atts.getValue("systemIdStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegateSystem",
			atts.getValue("systemIdStartString"),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("delegateURI")) {
	if (checkAttributes(atts, "uriStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_URI;
	  entryArgs.add(atts.getValue("uriStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegateURI",
			atts.getValue("uriStartString"),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("rewriteSystem")) {
	if (checkAttributes(atts, "systemIdStartString", "rewritePrefix")) {
	  entryType = Catalog.REWRITE_SYSTEM;
	  entryArgs.add(atts.getValue("systemIdStartString"));
	  entryArgs.add(atts.getValue("rewritePrefix"));

	  debug.message(4, "rewriteSystem",
			atts.getValue("systemIdStartString"),
			atts.getValue("rewritePrefix"));
	}
      } else if (localName.equals("rewriteURI")) {
	if (checkAttributes(atts, "uriStartString", "rewritePrefix")) {
	  entryType = Catalog.REWRITE_URI;
	  entryArgs.add(atts.getValue("uriStartString"));
	  entryArgs.add(atts.getValue("rewritePrefix"));

	  debug.message(4, "rewriteURI",
			atts.getValue("uriStartString"),
			atts.getValue("rewritePrefix"));
	}
      } else if (localName.equals("nextCatalog")) {
	if (checkAttributes(atts, "catalog")) {
	  entryType = Catalog.CATALOG;
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "nextCatalog", atts.getValue("catalog"));
	}
      } else if (localName.equals("public")) {
	if (checkAttributes(atts, "publicId", "uri")) {
	  entryType = Catalog.PUBLIC;
	  entryArgs.add(atts.getValue("publicId"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "public",
			PublicId.normalize(atts.getValue("publicId")),
			atts.getValue("uri"));
	}
      } else if (localName.equals("system")) {
	if (checkAttributes(atts, "systemId", "uri")) {
	  entryType = Catalog.SYSTEM;
	  entryArgs.add(atts.getValue("systemId"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "system",
			atts.getValue("systemId"),
			atts.getValue("uri"));
	}
      } else if (localName.equals("uri")) {
	if (checkAttributes(atts, "name", "uri")) {
	  entryType = Catalog.URI;
	  entryArgs.add(atts.getValue("name"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "uri",
			atts.getValue("name"),
			atts.getValue("uri"));
	}
      } else if (localName.equals("catalog")) {
	// nop, start of catalog
      } else if (localName.equals("group")) {
	// nop, a group
      } else {
	// This is equivalent to an invalid catalog entry type
	debug.message(1, "Invalid catalog entry type", localName);
      }

      if (entryType >= 0) {
	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry", localName);
	  }
	}
      }
    }

    if (namespaceURI != null && tr9401NamespaceName.equals(namespaceURI)
	&& !inExtension) {
      // This is a TR9401 Catalog entry

      if (atts.getValue("xml:base") != null) {
	String baseURI = atts.getValue("xml:base");
	entryType = Catalog.BASE;
	entryArgs.add(baseURI);
	baseURIStack.push(baseURI);

	debug.message(4, "xml:base", baseURI);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (base)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	baseURIStack.push(baseURIStack.peek());
      }

      if (localName.equals("doctype")) {
	entryType = catalog.DOCTYPE;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("document")) {
	entryType = catalog.DOCUMENT;
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("dtddecl")) {
	entryType = catalog.DTDDECL;
	entryArgs.add(atts.getValue("publicId"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("entity")) {
	entryType = Catalog.ENTITY;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("linktype")) {
	entryType = Catalog.LINKTYPE;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("notation")) {
	entryType = Catalog.NOTATION;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("sgmldecl")) {
	entryType = Catalog.SGMLDECL;
	entryArgs.add(atts.getValue("uri"));
      } else {
	// This is equivalent to an invalid catalog entry type
	debug.message(1, "Invalid catalog entry type", localName);
      }

      if (entryType >= 0) {
	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry", localName);
	  }
	}
      }
    }
  }
public void startElement (String namespaceURI,
			    String localName,
			    String qName,
			    Attributes atts)
    throws SAXException {

    int entryType = -1;
    Vector entryArgs = new Vector();

    namespaceStack.push(namespaceURI);

    boolean inExtension = inExtensionNamespace();

    if (namespaceURI != null && namespaceName.equals(namespaceURI)
	&& !inExtension) {
      // This is an XML Catalog entry

      if (atts.getValue("xml:base") != null) {
	String baseURI = atts.getValue("xml:base");
	entryType = Catalog.BASE;
	entryArgs.add(baseURI);
	baseURIStack.push(baseURI);

	debug.message(4, "xml:base", baseURI);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (base)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	baseURIStack.push(baseURIStack.peek());
      }

      if ((localName.equals("catalog") || localName.equals("group"))
	  && atts.getValue("prefer") != null) {
	String override = atts.getValue("prefer");

	if (override.equals("public")) {
	  override = "yes";
	} else if (override.equals("system")) {
	  override = "no";
	} else {
	  debug.message(1,
			"Invalid prefer: must be 'system' or 'public'",
			localName);
	  override = catalog.getDefaultOverride();
	}

	entryType = Catalog.OVERRIDE;
	entryArgs.add(override);
	overrideStack.push(override);

	debug.message(4, "override", override);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (override)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	overrideStack.push(overrideStack.peek());
      }

      if (localName.equals("delegatePublic")) {
	if (checkAttributes(atts, "publicIdStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_PUBLIC;
	  entryArgs.add(atts.getValue("publicIdStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegatePublic",
			PublicId.normalize(atts.getValue("publicIdStartString")),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("delegateSystem")) {
	if (checkAttributes(atts, "systemIdStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_SYSTEM;
	  entryArgs.add(atts.getValue("systemIdStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegateSystem",
			atts.getValue("systemIdStartString"),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("delegateURI")) {
	if (checkAttributes(atts, "uriStartString", "catalog")) {
	  entryType = Catalog.DELEGATE_URI;
	  entryArgs.add(atts.getValue("uriStartString"));
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "delegateURI",
			atts.getValue("uriStartString"),
			atts.getValue("catalog"));
	}
      } else if (localName.equals("rewriteSystem")) {
	if (checkAttributes(atts, "systemIdStartString", "rewritePrefix")) {
	  entryType = Catalog.REWRITE_SYSTEM;
	  entryArgs.add(atts.getValue("systemIdStartString"));
	  entryArgs.add(atts.getValue("rewritePrefix"));

	  debug.message(4, "rewriteSystem",
			atts.getValue("systemIdStartString"),
			atts.getValue("rewritePrefix"));
	}
      } else if (localName.equals("rewriteURI")) {
	if (checkAttributes(atts, "uriStartString", "rewritePrefix")) {
	  entryType = Catalog.REWRITE_URI;
	  entryArgs.add(atts.getValue("uriStartString"));
	  entryArgs.add(atts.getValue("rewritePrefix"));

	  debug.message(4, "rewriteURI",
			atts.getValue("uriStartString"),
			atts.getValue("rewritePrefix"));
	}
      } else if (localName.equals("nextCatalog")) {
	if (checkAttributes(atts, "catalog")) {
	  entryType = Catalog.CATALOG;
	  entryArgs.add(atts.getValue("catalog"));

	  debug.message(4, "nextCatalog", atts.getValue("catalog"));
	}
      } else if (localName.equals("public")) {
	if (checkAttributes(atts, "publicId", "uri")) {
	  entryType = Catalog.PUBLIC;
	  entryArgs.add(atts.getValue("publicId"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "public",
			PublicId.normalize(atts.getValue("publicId")),
			atts.getValue("uri"));
	}
      } else if (localName.equals("system")) {
	if (checkAttributes(atts, "systemId", "uri")) {
	  entryType = Catalog.SYSTEM;
	  entryArgs.add(atts.getValue("systemId"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "system",
			atts.getValue("systemId"),
			atts.getValue("uri"));
	}
      } else if (localName.equals("uri")) {
	if (checkAttributes(atts, "name", "uri")) {
	  entryType = Catalog.URI;
	  entryArgs.add(atts.getValue("name"));
	  entryArgs.add(atts.getValue("uri"));

	  debug.message(4, "uri",
			atts.getValue("name"),
			atts.getValue("uri"));
	}
      } else if (localName.equals("catalog")) {
	// nop, start of catalog
      } else if (localName.equals("group")) {
	// nop, a group
      } else {
	// This is equivalent to an invalid catalog entry type
	debug.message(1, "Invalid catalog entry type", localName);
      }

      if (entryType >= 0) {
	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry", localName);
	  }
	}
      }
    }

    if (namespaceURI != null && tr9401NamespaceName.equals(namespaceURI)
	&& !inExtension) {
      // This is a TR9401 Catalog entry

      if (atts.getValue("xml:base") != null) {
	String baseURI = atts.getValue("xml:base");
	entryType = Catalog.BASE;
	entryArgs.add(baseURI);
	baseURIStack.push(baseURI);

	debug.message(4, "xml:base", baseURI);

	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry (base)", localName);
	  }
	}

	entryType = -1;
	entryArgs = new Vector();

      } else {
	baseURIStack.push(baseURIStack.peek());
      }

      if (localName.equals("doctype")) {
	entryType = catalog.DOCTYPE;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("document")) {
	entryType = catalog.DOCUMENT;
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("dtddecl")) {
	entryType = catalog.DTDDECL;
	entryArgs.add(atts.getValue("publicId"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("entity")) {
	entryType = Catalog.ENTITY;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("linktype")) {
	entryType = Catalog.LINKTYPE;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("notation")) {
	entryType = Catalog.NOTATION;
	entryArgs.add(atts.getValue("name"));
	entryArgs.add(atts.getValue("uri"));
      } else if (localName.equals("sgmldecl")) {
	entryType = Catalog.SGMLDECL;
	entryArgs.add(atts.getValue("uri"));
      } else {
	// This is equivalent to an invalid catalog entry type
	debug.message(1, "Invalid catalog entry type", localName);
      }

      if (entryType >= 0) {
	try {
	  CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	  catalog.addEntry(ce);
	} catch (CatalogException cex) {
	  if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	    debug.message(1, "Invalid catalog entry type", localName);
	  } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	    debug.message(1, "Invalid catalog entry", localName);
	  }
	}
      }
    }
  }
The SAX <code>startElement</code> method recognizes elements
from the plain catalog format and instantiates CatalogEntry
objects for them.

@param namespaceURI The namespace name of the element.
@param localName The local name of the element.
@param qName The QName of the element.
@param atts The list of attributes on the element.

@see CatalogEntry