/*
* © Copyright IBM Corp. 2012
*
* 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 com.ibm.commons.xml.drivers;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.w3c.dom.traversal.DocumentTraversal;
import org.xml.sax.InputSource;
import com.ibm.commons.util.StringUtil;
import com.ibm.commons.xml.Format;
import com.ibm.commons.xml.XMLException;
/**
* Abstract XML service class with utlity functions.
*/
public abstract class AbstractDriver implements XMLParserDriver {
public AbstractDriver() {
}
// =========================================================================================
// Document creation
// =========================================================================================
public Document createDocument(String namespaceURI, String qualifiedName, DocumentType doctype) throws XMLException {
try {
// PHIL:
// It seems that xerces is complaining when a a document is created with a doctype
// and when the namespace URI is null.
// We overcome this by creating a dummy root element that is then removed.
if(doctype!=null) {
if(namespaceURI==null && qualifiedName==null) {
Document doc = getDOMImplementation().createDocument(null,"ns",doctype); // $NON-NLS-1$
doc.removeChild(doc.getDocumentElement());
return doc;
}
}
// Some parsers do *not* support creating a document with both being null
// We delegate to JAXP in this case
if(namespaceURI==null && qualifiedName==null) {
return createDocument();
}
return getDOMImplementation().createDocument(namespaceURI,qualifiedName,doctype);
} catch(Exception e) {
throw new XMLException(e,"Error while creating new document"); // $NLS-AbstractDriver.Errorwhilecreatingnewdocument-1$
}
}
protected Document createDocument() throws Exception {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
return builder.newDocument();
}
public DocumentType createDocumentType(String qualifiedName, String publicId, String systemId) throws XMLException {
try {
return getDOMImplementation().createDocumentType(qualifiedName,publicId,systemId);
} catch(Exception e) {
throw new XMLException(e,"Error while parsing XML stream"); // $NLS-AbstractDriver.ErrorwhileparsingXMLstream-1$
}
}
// =========================================================================================
// Document parsing
// =========================================================================================
protected DocumentBuilderFactory createDocumentBuilderFactory(boolean resolveEntities, boolean validate) {
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
dbFactory.setNamespaceAware(true);
dbFactory.setExpandEntityReferences(resolveEntities);
dbFactory.setValidating(validate);
return dbFactory;
}
public Document parse(InputStream is, boolean resolveEntities, boolean ignoreBlanks, boolean validate) throws XMLException {
try {
DocumentBuilderFactory dbFactory = createDocumentBuilderFactory(resolveEntities,validate);
DocumentBuilder docBuilder = dbFactory.newDocumentBuilder();
Document doc = docBuilder.parse(is);
if (ignoreBlanks) {
removeEmtyTextNodes(doc);
}
return doc;
} catch(Exception e) {
throw new XMLException(e,"Error while parsing XML stream"); // $NLS-AbstractDriver.ErrorwhileparsingXMLstream.1-1$
}
}
public Document parse(Reader reader, boolean resolveEntities, boolean ignoreBlanks, boolean validate) throws XMLException {
try {
DocumentBuilderFactory dbFactory = createDocumentBuilderFactory(resolveEntities,validate);
DocumentBuilder docBuilder = dbFactory.newDocumentBuilder();
Document doc = docBuilder.parse(new InputSource(reader));
if (ignoreBlanks) {
removeEmtyTextNodes(doc);
}
return doc;
} catch(Exception e) {
throw new XMLException(e,"Error while parsing XML stream"); // $NLS-AbstractDriver.ErrorwhileparsingXMLstream.2-1$
}
}
public static void removeEmtyTextNodes(Node node) {
NodeList nodeList = node.getChildNodes();
int length = nodeList.getLength();
for(int i=length-1; i>=0; i--) {
Node child = nodeList.item(i);
if(child.getNodeType()==Node.TEXT_NODE) {
Text txt = (Text) child;
String data = txt.getData();
if(StringUtil.isSpace(data)) {
node.removeChild(child);
}
} else {
removeEmtyTextNodes(child);
}
}
}
// =========================================================================================
// Document serialization
// =========================================================================================
public void serialize(OutputStream os, Node node, Format format) throws XMLException {
StreamResult result = new StreamResult(os);
serialize(node,result,format);
}
public void serialize(Writer writer, Node node, Format format) throws XMLException {
StreamResult result = new StreamResult(writer);
serialize(node,result,format);
}
private void serialize(Node node, StreamResult result, Format format) throws XMLException {
try {
if(format==null) {
format = Format.defaultFormat;
}
DOMSource domSource = new DOMSource(node);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT,format.indent>0?"yes":"no"); // $NON-NLS-1$ $NON-NLS-2$
transformer.setOutputProperty(OutputKeys.ENCODING,format.encoding);
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION,format.xmlDecl?"no":"yes"); // $NON-NLS-1$ $NON-NLS-2$
transformer.transform(domSource, result);
} catch(Exception e) {
throw new XMLException(e,"Error while converting XML document to string"); // $NLS-AbstractDriver.ErrorwhileconvertingXMLdocumentto-1$
}
}
// =========================================================================================
// Document traversal
// =========================================================================================
public DocumentTraversal getDocumentTraversal(Document doc) {
// That should work for almost all the drivers...
return (DocumentTraversal)doc;
}
}