/**
* Copyright 2006 OCLC Online Computer Library Center 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 info.openurl.oom.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* General purpose static methods for manipulating XML.
*
* @author Jeffrey A. Young
*/
public class XMLHelper {
// private static HashMap builderMap = new HashMap();
private static DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
private static TransformerFactory tFactory = TransformerFactory.newInstance();
// private static HashMap transformerMap = new HashMap();
static {
dbFactory.setNamespaceAware(true);
}
private static Element xmlnsEl;
static {
try {
DOMImplementation impl =
getThreadedDocumentBuilder().getDOMImplementation();
Document xmlnsDoc = impl.createDocument("uri:foo", "foo:xmlnsDoc",
null);
xmlnsEl = xmlnsDoc.getDocumentElement();
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:foo", "uri:foo");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:ctx", "info:ofi/fmt:xml:xsd:ctx");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:oai", "http://www.openarchives.org/OAI/2.0/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:oai_dc", "http://www.openarchives.org/OAI/2.0/oai_dc/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:dc", "http://purl.org/dc/elements/1.1/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:srw", "http://www.loc.gov/zing/srw/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:mets", "http://www.loc.gov/METS/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:xlink", "http://www.w3.org/TR/xlink");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:config", "info:sid/localhost:CollectionSimpleSchemas:config");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:purl", "info:sid/localhost:CollectionSimpleSchemas:purl");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:reg", "http://info-uri.info/registry");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:wr", "http://errol.oclc.org/oai:xmlregistry.oclc.org:errol/WikiRepository");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:pearsIdx", "http://www.oclc.org/pears/");
xmlnsEl.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:oomRef", "info:collections/oomImpls/oomRef");
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
}
/**
* Get a thread-safe Transformer without an assigned transform. This is useful
* for transforming a DOM Document into XML text.
* @param omitXmlDeclaration
* @return an "identity" Transformer assigned to the current thread
* @throws TransformerConfigurationException
*/
public static Transformer getThreadedIdentityTransformer(
boolean omitXmlDeclaration)
throws TransformerConfigurationException {
return getThreadedTransformer(omitXmlDeclaration,
// transformerMap,
null,
(String) null);
}
/**
* Get a thread-safe Transformer without an assigned transform. This is useful
* for transforming a DOM Document into XML text.
* @param omitXmlDeclaration
* @param standalone
* @return an Identity Transformer
* @throws TransformerConfigurationException
*/
public static Transformer getThreadedIdentityTransformer(
boolean omitXmlDeclaration, boolean standalone)
throws TransformerConfigurationException {
return getThreadedTransformer(omitXmlDeclaration, standalone,
// transformerMap,
null,
(String) null);
}
private static Transformer getThreadedTransformer(
boolean omitXmlDeclaration,
boolean standalone, Map threadMap, String xslURL)
throws TransformerConfigurationException {
Thread currentThread = Thread.currentThread();
Transformer transformer = null;
if (threadMap != null) {
transformer = (Transformer) threadMap.get(currentThread);
}
if (transformer == null) {
if (xslURL == null) {
transformer = tFactory.newTransformer(); // "never null"
} else {
transformer = tFactory.newTransformer(new StreamSource(xslURL));
}
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
if (threadMap != null) {
threadMap.put(currentThread, transformer);
}
}
transformer.setOutputProperty(OutputKeys.STANDALONE,
standalone?"yes":"no");
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION,
omitXmlDeclaration?"yes":"no");
return transformer;
}
/**
* Get a thread-safe Transformer.
* @param omitXmlDeclaration
* @param threadMap
* @param xslURL
* @return a thread-safe Transformer
* @throws TransformerConfigurationException
*/
public static Transformer getThreadedTransformer(boolean omitXmlDeclaration,
Map threadMap, String xslURL)
throws TransformerConfigurationException {
return getThreadedTransformer(omitXmlDeclaration, true, threadMap,
xslURL);
}
/**
* Get an Element with some handy xmlns attributes defined.
* This comes in handy for calling XPathAPI methods.
* @return an Element containing various xmlns attributes.
*/
public static Element getXmlnsEl() {
return xmlnsEl;
}
/**
* Grab the Document found at the specified URL.
*
* @param ref the URL location of an XML document.
* @return a Document loaded from the specified URL.
* @throws SAXException
* @throws IOException
* @throws ParserConfigurationException
*/
public static Document parse(String ref)
throws SAXException, IOException, ParserConfigurationException {
String protocol = ref.split(":", 2)[0];
return parse(protocol, new InputSource(ref));
}
/**
* Grab the Document found at the specified URL.
*
* @param protocol
* @param is
* @return a Document loaded from the specified URL.
* @throws SAXException
* @throws IOException
* @throws ParserConfigurationException
*/
public static Document parse(String protocol, InputSource is)
throws SAXException, IOException, ParserConfigurationException {
if ("http".equals(protocol)) {
return getThreadedDocumentBuilder().parse(is);
}
throw new IOException("Protocol handler not implemented yet: " + protocol);
}
/**
* Grab the Document loaded from the specified InputSource.
*
* @param is
* @return a Document loaded from the specified InputSource
* @throws SAXException
* @throws IOException
* @throws ParserConfigurationException
*/
public static Document parse(InputSource is)
throws SAXException, IOException, ParserConfigurationException {
return getThreadedDocumentBuilder().parse(is);
}
/**
* Grab the Document loaded from the specified InputStream
*
* @param is
* @return a Document loaded from the specified InputStream.
* @throws SAXException
* @throws IOException
* @throws ParserConfigurationException
*/
public static Document parse(InputStream is)
throws SAXException, IOException, ParserConfigurationException {
return getThreadedDocumentBuilder().parse(is);
}
/**
* Get a thread-safe DocumentBuilder
* @return a namespaceAware DocumentBuilder assigned to the current thread
* @throws ParserConfigurationException
*/
public static DocumentBuilder getThreadedDocumentBuilder()
throws ParserConfigurationException {
// Thread currentThread = Thread.currentThread();
// DocumentBuilder builder =
// (DocumentBuilder) builderMap.get(currentThread);
// if (builder == null) {
// builder = dbFactory.newDocumentBuilder();
// builderMap.put(currentThread, builder);
// }
DocumentBuilder builder = dbFactory.newDocumentBuilder();
return builder;
}
/**
* XML-encode a String
* @param value the String to be XML-encoded
* @return the XML-encoded String
*/
public static String encode(String value) {
StringBuffer sb = new StringBuffer();
for (int i=0; i<value.length(); ++i) {
char c = value.charAt(i);
switch (c) {
case '&':
sb.append("&");
break;
case '<':
sb.append("<");
break;
case '>':
sb.append(">");
break;
case '\'':
sb.append("'");
break;
case '"':
sb.append(""");
break;
default:
sb.append(c);
}
}
return sb.toString();
}
/**
* Transform a DOM Node into an XML String.
* @param node
* @return an XML String representation of the specified Node
* @throws TransformerException
*/
public static String toString(Node node)
throws TransformerException {
return toString(node, true);
}
/**
* Transform a DOM Node into an XML String
* @param node
* @param omitXMLDeclaration
* @return an XML String representation of the specified Node
* @throws TransformerException
*/
public static String toString(Node node, boolean omitXMLDeclaration)
throws TransformerException {
StringWriter writer = new StringWriter();
Transformer transformer =
getThreadedIdentityTransformer(omitXMLDeclaration);
Source source = new DOMSource(node);
Result result = new StreamResult(writer);
transformer.transform(source, result);
return writer.toString();
}
/**
* Remove named nodes of the specified nodeType from the
* specified node.
* @param node the node to be cleaned.
* @param nodeType the type of nodes to be removed.
* @param name the name of nodes to be removed.
*/
public static void removeAll(Node node, short nodeType, String name) {
if (node.getNodeType() == nodeType &&
(name == null || node.getNodeName().equals(name))) {
node.getParentNode().removeChild(node);
} else {
// Visit the children
NodeList list = node.getChildNodes();
for (int i=0; i<list.getLength(); i++) {
removeAll(list.item(i), nodeType, name);
}
}
}
}