org.broadleafcommerce.common.extensibility.context.merge.MergePoint Maven / Gradle / Ivy
/*
* #%L
* BroadleafCommerce Common Libraries
* %%
* Copyright (C) 2009 - 2013 Broadleaf Commerce
* %%
* 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.
* #L%
*/
package org.broadleafcommerce.common.extensibility.context.merge;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.broadleafcommerce.common.extensibility.context.merge.handlers.MergeHandler;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* This class provides the xml merging apparatus at a defined XPath merge point in
* 2 xml documents. The MergeHandler that embodies the XPath point can have
* embedded XPath merge points, resulting in a cumulative effect with varying
* merge behavior for a sector of the documents. For example, it may be desirable
* to replace all the child nodes of a given node with all the child nodes from the same
* parent node in the patch document, with the exception of a single node. That single
* node may instead contribute its contents in a additive fashion (rather than replace).
*
* @author jfischer
*
*/
public class MergePoint {
private static final Log LOG = LogFactory.getLog(MergePoint.class);
private MergeHandler handler;
private Document doc1;
private Document doc2;
private XPath xPath;
public MergePoint(MergeHandler handler, Document doc1, Document doc2) {
this.handler = handler;
this.doc1 = doc1;
this.doc2 = doc2;
XPathFactory factory=XPathFactory.newInstance();
xPath=factory.newXPath();
}
/**
* Execute the merge operation and also provide a list of nodes that have already been
* merged. It is up to the handler implementation to respect or ignore this list.
*
* @param exhaustedNodes
* @return list of merged nodes
* @throws XPathExpressionException
*/
public Node[] merge(List exhaustedNodes) throws XPathExpressionException, TransformerException {
return merge(handler, exhaustedNodes);
}
private Node[] merge(MergeHandler handler, List exhaustedNodes) throws XPathExpressionException, TransformerException {
if (LOG.isDebugEnabled()) {
LOG.debug("Processing handler: " + handler.getXPath());
}
if (handler.getChildren() != null) {
MergeHandler[] children = handler.getChildren();
for (MergeHandler aChildren : children) {
Node[] temp = merge(aChildren, exhaustedNodes);
if (temp != null) {
Collections.addAll(exhaustedNodes, temp);
}
}
}
String[] xPaths = handler.getXPath().split(" ");
List nodeList1 = new ArrayList();
List nodeList2 = new ArrayList();
for (String xPathVal : xPaths) {
NodeList temp1 = (NodeList) xPath.evaluate(xPathVal, doc1, XPathConstants.NODESET);
if (temp1 != null) {
int length = temp1.getLength();
for (int j=0;j