XMLMergerRunner.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.util.xml;

import com.liferay.portal.kernel.io.unsync.UnsyncByteArrayOutputStream;
import com.liferay.portal.kernel.io.unsync.UnsyncStringReader;
import com.liferay.portal.kernel.util.FileUtil;
import com.liferay.portal.kernel.util.StringUtil;
import com.liferay.portal.kernel.util.Validator;
import com.liferay.util.xml.descriptor.XMLDescriptor;

import java.io.File;
import java.io.IOException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

/**
 * @author Jorge Ferrer
 */
public class XMLMergerRunner {

	public XMLMergerRunner(String descriptorClassName) {
		if (Validator.isNotNull(descriptorClassName)) {
			_descriptorClassName = descriptorClassName;
		}
		else {
			_descriptorClassName = _AUTO_DESCRIPTOR;
		}
	}

	public void mergeAndSave(File masterFile, File slaveFile, File mergedFile)
		throws ClassNotFoundException, DocumentException,
			   IllegalAccessException, InstantiationException, IOException {

		String xml1 = FileUtil.read(masterFile);
		String xml2 = FileUtil.read(slaveFile);

		String mergedXml = _merge(xml1, xml2);

		FileUtil.write(mergedFile, mergedXml);
	}

	public void mergeAndSave(
			String masterFile, String slaveFile, String mergedFile)
		throws ClassNotFoundException, DocumentException,
			   IllegalAccessException, InstantiationException, IOException {

		mergeAndSave(
			new File(masterFile), new File(slaveFile), new File(mergedFile));
	}

	private String _documentToString(Document doc, String docType)
		throws IOException {

		UnsyncByteArrayOutputStream unsyncByteArrayOutputStream =
			new UnsyncByteArrayOutputStream();

		OutputFormat format = OutputFormat.createPrettyPrint();

		format.setIndent("\t");
		format.setLineSeparator("\n");

		XMLWriter writer = new XMLWriter(unsyncByteArrayOutputStream, format);

		writer.write(doc);

		String xml = unsyncByteArrayOutputStream.toString();

		int pos = xml.indexOf("<?");

		String header = xml.substring(pos, xml.indexOf("?>", pos) + 2);

		xml = StringUtil.replace(xml, header, "");
		xml = header + "\n" + docType + "\n" + xml;

		return xml;
	}

	private String _merge(String masterXml, String slaveXml)
		throws ClassNotFoundException, DocumentException,
			   IllegalAccessException, InstantiationException, IOException {

		int pos = masterXml.indexOf("<!DOCTYPE");

		String masterDoctype = "";

		if (pos >= 0) {
			masterDoctype = masterXml.substring(
				pos, masterXml.indexOf(">", pos) + 1);

			masterXml = StringUtil.replace(masterXml, masterDoctype, "");
		}

		pos = slaveXml.indexOf("<!DOCTYPE");

		String slaveDoctype = "";

		if (pos >= 0) {
			slaveDoctype = slaveXml.substring(
				pos, slaveXml.indexOf(">", pos) + 1);

			slaveXml = StringUtil.replace(slaveXml, slaveDoctype, "");
		}

		String doctype = null;

		if (Validator.isNotNull(masterDoctype)) {
			doctype = masterDoctype;
		}
		else {
			doctype = slaveDoctype;
		}

		SAXReader reader = new SAXReader();

		Document masterDoc = reader.read(new UnsyncStringReader(masterXml));
		Document slaveDoc = reader.read(new UnsyncStringReader(slaveXml));

		XMLDescriptor descriptor = null;

		if (_descriptorClassName.equals(_AUTO_DESCRIPTOR)) {
			descriptor = XMLTypeDetector.determineType(doctype, masterDoc);
		}
		else {
			Class<?> clazz = Class.forName(_descriptorClassName);

			descriptor = (XMLDescriptor)clazz.newInstance();
		}

		XMLMerger merger = new XMLMerger(descriptor);

		Document mergedDoc = merger.merge(masterDoc, slaveDoc);

		return _documentToString(mergedDoc, doctype);
	}

	private static final String _AUTO_DESCRIPTOR = "auto";

	private final String _descriptorClassName;

}