/*
* Copyright 2005 The Apache Software Foundation
*
* 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 org.mybatis.generator.internal;
import static org.mybatis.generator.internal.util.messages.Messages.getString;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.mybatis.generator.api.GeneratedXmlFile;
import org.mybatis.generator.config.MergeConstants;
import org.mybatis.generator.exception.ShellException;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* This class handles the task of merging changes into an existing XML file.
*
* @author Jeff Butler
*/
public class XmlFileMergerJaxp {
private static class NullEntityResolver implements EntityResolver {
/**
* returns an empty reader. This is done so that the parser doesn't
* attempt to read a DTD. We don't need that support for the merge and
* it can cause problems on systems that aren't Internet connected.
*/
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
StringReader sr = new StringReader(""); //$NON-NLS-1$
return new InputSource(sr);
}
}
/**
* Utility class - no instances allowed
*/
private XmlFileMergerJaxp() {
super();
}
public static String getMergedSource(GeneratedXmlFile generatedXmlFile, File existingFile) throws ShellException {
try {
return getMergedSource(new InputSource(new StringReader(generatedXmlFile.getFormattedContent())),
new InputSource(new FileReader(existingFile)), existingFile.getName());
} catch (IOException e) {
throw new ShellException(getString("Warning.13", //$NON-NLS-1$
existingFile.getName()), e);
} catch (SAXException e) {
throw new ShellException(getString("Warning.13", //$NON-NLS-1$
existingFile.getName()), e);
} catch (ParserConfigurationException e) {
throw new ShellException(getString("Warning.13", //$NON-NLS-1$
existingFile.getName()), e);
}
}
public static String getMergedSource(InputSource newFile, InputSource existingFile, String existingFileName)
throws IOException, SAXException, ParserConfigurationException, ShellException {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setExpandEntityReferences(false);
DocumentBuilder builder = factory.newDocumentBuilder();
builder.setEntityResolver(new NullEntityResolver());
Document existingDocument = builder.parse(existingFile);
Document newDocument = builder.parse(newFile);
DocumentType newDocType = newDocument.getDoctype();
DocumentType existingDocType = existingDocument.getDoctype();
if (!newDocType.getName().equals(existingDocType.getName())) {
throw new ShellException(getString("Warning.12", //$NON-NLS-1$
existingFileName));
}
Element existingRootElement = existingDocument.getDocumentElement();
Element newRootElement = newDocument.getDocumentElement();
// reconcile the root element attributes -
// take all attributes from the new element and add to the existing
// element
// remove all attributes from the existing root element
NamedNodeMap attributes = existingRootElement.getAttributes();
int attributeCount = attributes.getLength();
for (int i = attributeCount - 1; i >= 0; i--) {
Node node = attributes.item(i);
existingRootElement.removeAttribute(node.getNodeName());
}
// add attributes from the new root node to the old root node
attributes = newRootElement.getAttributes();
attributeCount = attributes.getLength();
for (int i = 0; i < attributeCount; i++) {
Node node = attributes.item(i);
existingRootElement.setAttribute(node.getNodeName(), node.getNodeValue());
}
// remove the old generated elements and any
// white space before the old nodes
List<Node> nodesToDelete = new ArrayList<Node>();
NodeList children = existingRootElement.getChildNodes();
int length = children.getLength();
for (int i = 0; i < length; i++) {
Node node = children.item(i);
if (isGeneratedNode(node)) {
nodesToDelete.add(node);
} else if (isWhiteSpace(node) && isGeneratedNode(children.item(i + 1))) {
nodesToDelete.add(node);
}
}
for (Node node : nodesToDelete) {
existingRootElement.removeChild(node);
}
// add the new generated elements
children = newRootElement.getChildNodes();
length = children.getLength();
Node firstChild = existingRootElement.getFirstChild();
for (int i = 0; i < length; i++) {
Node node = children.item(i);
// don't add the last node if it is only white space
if (i == length - 1) {
if (isWhiteSpace(node)) {
break;
}
}
Node newNode = existingDocument.importNode(node, true);
if (firstChild == null) {
existingRootElement.appendChild(newNode);
} else {
existingRootElement.insertBefore(newNode, firstChild);
}
}
// pretty print the result
return prettyPrint(existingDocument);
}
private static String prettyPrint(Document document) throws ShellException {
DomWriter dw = new DomWriter();
String s = dw.toString(document);
return s;
}
private static boolean isGeneratedNode(Node node) {
boolean rc = false;
if (node != null && node.getNodeType() == Node.ELEMENT_NODE) {
Element element = (Element) node;
String id = element.getAttribute("id"); //$NON-NLS-1$
if (id != null) {
for (String prefix : MergeConstants.OLD_XML_ELEMENT_PREFIXES) {
if (id.startsWith(prefix)) {
rc = true;
break;
}
}
}
if (rc == false) {
// check for new node format - if the first non-whitespace node
// is an XML comment, and the comment includes
// one of the old element tags,
// then it is a generated node
NodeList children = node.getChildNodes();
int length = children.getLength();
for (int i = 0; i < length; i++) {
Node childNode = children.item(i);
if (isWhiteSpace(childNode)) {
continue;
} else if (childNode.getNodeType() == Node.COMMENT_NODE) {
Comment comment = (Comment) childNode;
String commentData = comment.getData();
for (String tag : MergeConstants.OLD_ELEMENT_TAGS) {
if (commentData.contains(tag)) {
rc = true;
break;
}
}
} else {
break;
}
}
}
}
return rc;
}
private static boolean isWhiteSpace(Node node) {
boolean rc = false;
if (node != null && node.getNodeType() == Node.TEXT_NODE) {
Text tn = (Text) node;
if (tn.getData().trim().length() == 0) {
rc = true;
}
}
return rc;
}
}