/*
* The MIT License
*
* Copyright (c) 2012-2013 IKEDA Yasuyuki
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package jp.ikedam.jenkins.plugins.jobcopy_builder;
import hudson.EnvVars;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
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 javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
/**
* Abstract class for job copy operation using XML DOM.
* @see jp.ikedam.jenkins.plugins.jobcopy_builder.JobcopyOperation
*/
public abstract class AbstractXmlJobcopyOperation extends JobcopyOperation
{
/**
* Performs modifications to job configure XML Document.
*
* @param doc XML Document of the job to be copied (job/NAME/config.xml)
* @param env Variables defined in the build.
* @param logger The output stream to log.
* @return modified XML Document. Return null if an error occurs.
*/
public abstract Document perform(Document doc, EnvVars env, PrintStream logger);
/**
* Returns modified XML string of the job configuration.
*
* @param xmlString the XML string of the job to be copied (job/NAME/config.xml)
* @param encoding the encoding of the XML.
* @param env Variables defined in the build.
* @param logger The output stream to log.
* @return modified XML string. Returns null if an error occurs.
* @see jp.ikedam.jenkins.plugins.jobcopy_builder.JobcopyOperation#perform(java.lang.String, java.lang.String, hudson.EnvVars, java.io.PrintStream)
*/
@Override
public String perform(String xmlString, String encoding, EnvVars env, PrintStream logger)
{
Document doc;
try
{
doc = getXmlDocumentFromString(xmlString, encoding, logger);
}
catch (Exception e)
{
logger.print("Error occured in XML operation");
e.printStackTrace(logger);
return null;
}
Document newDoc = perform(doc, env, logger);
if(newDoc == null)
{
// It seems that an error occurred in XML processing.
return null;
}
try
{
return getXmlString(newDoc);
}
catch (Exception e)
{
logger.print("Error occured in XML operation");
e.printStackTrace(logger);
return null;
}
}
/**
* Retrieve the XML string from XML Document object
*
* @param doc the XML Document object.
* @return the XML string
* @throws TransformerException
*/
private String getXmlString(Document doc)
throws TransformerException
{
TransformerFactory tfactory = TransformerFactory.newInstance();
Transformer transformer = tfactory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StringWriter sw = new StringWriter();
transformer.transform(new DOMSource(doc), new StreamResult(sw));
return sw.toString();
}
/**
* Construct a XML Document object from a XML string.
*
* @param xmlString a XML string.
* @param encoding encoding of xmlString.
* @return Constructed XML Document object.
* @throws ParserConfigurationException
* @throws UnsupportedEncodingException
* @throws SAXException
* @throws IOException
*/
private Document getXmlDocumentFromString(String xmlString, String encoding, final PrintStream logger)
throws ParserConfigurationException,UnsupportedEncodingException,SAXException,IOException
{
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
//domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
builder.setErrorHandler(new ErrorHandler(){
@Override
public void warning(SAXParseException exception)
throws SAXException
{
exception.printStackTrace(logger);
}
@Override
public void error(SAXParseException exception) throws SAXException
{
exception.printStackTrace(logger);
}
@Override
public void fatalError(SAXParseException exception)
throws SAXException
{
exception.printStackTrace(logger);
}
});
InputStream is = new ByteArrayInputStream((encoding != null)?
xmlString.getBytes(encoding)
:xmlString.getBytes()
);
return builder.parse(is);
}
/****** Utility methods working with XML. Usable from subclasses. ******/
/**
* Retrieve a XML node using XPath.
*
* Returns null in following cases:
* <ul>
* <li>No node found.</li>
* <li>More than one node found.</li>
* </ul>
*
* @param doc the XML Document object.
* @param xpath a XPath specifying the retrieving node.
* @return the retrieved node.
* @throws XPathExpressionException
*/
protected Node getNode(Document doc, String xpath)
throws XPathExpressionException
{
NodeList nodeList = getNodeList(doc, xpath);
if(nodeList.getLength() != 1)
{
return null;
}
return nodeList.item(0);
}
/**
* Retrieve a XML node list using XPath.
*
* @param doc the XML Document object.
* @param xpathExpression a XPath specifying the retrieving nodes.
* @return retrieved nodes in NodeList
* @throws XPathExpressionException
*/
protected NodeList getNodeList(Document doc, String xpathExpression)
throws XPathExpressionException
{
XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
XPathExpression expr = xpath.compile(xpathExpression);
return (NodeList)expr.evaluate(doc, XPathConstants.NODESET);
}
/**
* Retrieve a XPath expression of a node.
*
* Use only for displaying purposes only.
* For this works not so strict,
* the return value supposes not to work proper
* with XPath processors.
*
* @param targetNode a node whose XPath expression is retrieved.
* @return XPath expression.
*/
protected String getXpath(Node targetNode)
{
StringBuilder pathBuilder = new StringBuilder();
for(Node node = targetNode; node != null && !(node instanceof Document); node = node.getParentNode())
{
if(node instanceof Text)
{
pathBuilder.insert(0, "text()");
pathBuilder.insert(0, '/');
}
else
{
pathBuilder.insert(0, node.getNodeName());
pathBuilder.insert(0, '/');
}
}
return pathBuilder.toString();
}
}