//------------------------------------------------------------------------------
// Copyright (c) 2005, 2007 IBM Corporation and others.
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// which accompanies this distribution, and is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// Contributors:
// IBM Corporation - initial implementation
//------------------------------------------------------------------------------
package org.eclipse.epf.common.utils;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.tools.ant.util.ReaderInputStream;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXParseException;
/**
* Utility class for processing XML documents.
*
* @author Kelvin Low
* @author Jinhua Xi
* @author Phong Nguyen Le
* @since 1.0
*/
public class XMLUtil {
/**
* XML declaration.
*/
public final static String XML_DECLARATION = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"; //$NON-NLS-1$
/**
* XML Escape characters.
*/
public final static String XML_AMP = "&"; //$NON-NLS-1$
public final static String XML_BACKSLASH = "\"; //$NON-NLS-1$
public final static String XML_APOS = "'"; //$NON-NLS-1$
public final static String XML_CR = "
"; //$NON-NLS-1$
public final static String XML_GT = ">"; //$NON-NLS-1$
public final static String XML_LT = "<"; //$NON-NLS-1$
public final static String XML_LF = "
"; //$NON-NLS-1$
public final static String XML_QUOT = """; //$NON-NLS-1$
public final static String XML_TAB = " "; //$NON-NLS-1$
private static final String CRLF = "\r\n"; //$NON-NLS-1$
private static final byte[] CRLF_BYTES = CRLF.getBytes();
/**
* Private constructor to prevent this class from being instantiated. All
* methods in this class should be static.
*/
private XMLUtil() {
}
/**
* Clones the given DOM node into the given DOM document.
*
* @param node
* The DOM node to clone.
* @param doc
* The target DOM document.
* @return The cloned node in the target DOM document.
*/
public static Node cloneNode(Node node, Document doc) {
Node clone = null;
switch (node.getNodeType()) {
case Node.ELEMENT_NODE:
clone = doc.createElement(node.getNodeName());
NamedNodeMap attrs = node.getAttributes();
for (int i = 0; i < attrs.getLength(); i++) {
Node attrNode = attrs.item(i);
Attr attrClone = doc.createAttribute(attrNode.getNodeName());
attrClone.setNodeValue(attrNode.getNodeValue());
((Element) clone).setAttributeNode(attrClone);
}
// Iterate through each child nodes.
NodeList childNodes = node.getChildNodes();
if (childNodes != null) {
for (int i = 0; i < childNodes.getLength(); i++) {
Node childNode = childNodes.item(i);
if (childNode == null) {
continue;
}
Node childClone = cloneNode(childNode, doc);
if (childClone == null) {
continue;
}
clone.appendChild(childClone);
}
}
break;
case Node.TEXT_NODE:
case Node.CDATA_SECTION_NODE:
clone = doc.createTextNode(node.getNodeName());
clone.setNodeValue(node.getNodeValue());
break;
}
return clone;
}
/**
* Escapes a XML attribute to make it XML parser friendly.
*
* @param str
* The XML attribute string.
* @return The escaped string.
*/
public static String escapeAttr(String str) {
if (str == null || str.length() == 0)
return ""; //$NON-NLS-1$
StringBuffer sb = new StringBuffer();
int len = str.length();
for (int i = 0; i < len; i++) {
char ch = str.charAt(i);
switch (ch) {
case '<':
sb.append(XML_LT);
break;
case '&':
sb.append(XML_AMP);
break;
case '"':
sb.append(XML_QUOT);
break;
default:
sb.append(ch);
break;
}
}
return sb.toString();
}
/**
* Escapes the given string to make it XML parser friendly.
*
* @param str
* The source string.
* @return The escaped string.
*/
public static String escape(String str) {
if (str == null || str.length() == 0)
return ""; //$NON-NLS-1$
StringBuffer sb = new StringBuffer();
int len = str.length();
for (int i = 0; i < len; i++) {
char ch = str.charAt(i);
switch (ch) {
case '<':
sb.append(XML_LT);
break;
case '>':
sb.append(XML_GT);
break;
case '&':
sb.append(XML_AMP);
break;
case '"':
sb.append(XML_QUOT);
break;
case '\'':
sb.append(XML_APOS);
break;
case '\r':
sb.append(XML_CR);
break;
case '\n':
sb.append(XML_LF);
break;
case '\\':
sb.append(XML_BACKSLASH);
break;
default:
sb.append(ch);
break;
}
}
return sb.toString();
}
/**
* Escapes the given string to make it XML parser friendly.
*
* @param str
* The source string.
* @param ignoreCRLF
* If true, do not escape the CR and LF characters.
* @return The escaped string.
*/
public static String escape(String str, boolean ignoreCRLF) {
if (str == null || str.length() == 0)
return ""; //$NON-NLS-1$
StringBuffer sb = new StringBuffer();
int len = str.length();
for (int i = 0; i < len; i++) {
char ch = str.charAt(i);
switch (ch) {
case '<':
sb.append(XML_LT);
break;
case '>':
sb.append(XML_GT);
break;
case '&':
// This is to avoid the double escaping (see Bugzilla 179921)
if (!str.startsWith(XML_LT+"p/", i) && !str.startsWith(XML_APOS, i) //$NON-NLS-1$
&& !str.startsWith(XML_AMP, i))
sb.append(XML_AMP);
else
sb.append(ch);
break;
case '"':
sb.append(XML_QUOT);
break;
case '\'':
sb.append(XML_APOS);
break;
case '\r':
if (ignoreCRLF)
sb.append(ch);
else
sb.append(XML_CR);
break;
case '\n':
if (ignoreCRLF)
sb.append(ch);
else
sb.append(XML_LF);
break;
default:
sb.append(ch);
break;
}
}
return sb.toString();
}
/**
* Unescapes the given XML string.
*
* @param str
* The source string.
* @return The escaped string.
*/
public static String unescape(String str) {
if (str == null || str.length() == 0)
return ""; //$NON-NLS-1$
StringBuffer sb = new StringBuffer();
int len = str.length();
for (int i = 0; i < len; i++) {
char ch = str.charAt(i);
switch (ch) {
case '&':
if (str.startsWith(XML_LT, i)) {
sb.append('<');
i += 3;
} else if (str.startsWith(XML_GT, i)) {
sb.append('>');
i += 3;
} else if (str.startsWith(XML_AMP, i)) {
sb.append('&');
i += 4;
} else if (str.startsWith(XML_QUOT, i)) {
sb.append('"');
i += 5;
} else if (str.startsWith(XML_APOS, i)) {
sb.append("\'"); //$NON-NLS-1$
i += 5;
} else if (str.startsWith(XML_CR, i)) {
sb.append('\r');
i += 4;
} else if (str.startsWith(XML_LF, i)) {
sb.append('\n');
i += 4;
} else {
sb.append(ch);
}
break;
default:
sb.append(ch);
break;
}
}
return sb.toString();
}
/**
* Writes the content of the given DOM document to the output stream.
*
* @param xmlDoc
* The DOM document.
* @param output
* The output stream.
* @throws IOException
* if an I/O error occur while accessing the output stream.
*/
public static void writeDocument(Document xmlDoc, OutputStream output)
throws IOException {
DataOutputStream out = new DataOutputStream(output);
writeNode(xmlDoc, "", out); //$NON-NLS-1$
out.flush();
}
/**
* Writes the content of the given DOM document to the PrintWriter.
*
* @param xmlDoc
* The DOM document.
* @param pw
* The PrintWriter object.
* @throws IOException
* if an I/O error occur while accessing the output stream.
*/
public static void writeDocument(Document xmlDoc, PrintWriter pw)
throws IOException {
ByteArrayOutputStream os = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(os);
writeNode(xmlDoc, "", out); //$NON-NLS-1$
out.flush();
// FIXME! Need to specify encoding?
String s = os.toString();
pw.write(s);
pw.flush();
}
/**
* Saves the content of the given DOM document to file.
*
* @param xmlDoc
* The DOM document.
* @param xmlFile
* The XML file.
* @throws IOException
* if an I/O error occur while accessing the output stream.
*/
public static void saveDocument(Document xmlDoc, String xmlFile)
throws IOException {
DataOutputStream out = new DataOutputStream(new FileOutputStream(
xmlFile));
writeNode(xmlDoc, "", out); //$NON-NLS-1$
out.flush();
out.close();
}
/**
* Saves the given XML string to the given file.
*
* @param xmlStr
* The XML string.
* @param xmlFile
* The XML file.
* @throws IOException
* if an I/O error occur while accessing the output stream.
*/
public static void saveDocument(String xmlStr, String xmlFile)
throws IOException {
DataOutputStream out = new DataOutputStream(new FileOutputStream(
xmlFile));
out.write(xmlStr.getBytes());
out.flush();
out.close();
}
/**
* Writes the given DOM tree node to the given output stream.
*
* @param node
* The DOM node.
* @param indent
* The string indentation (containing space characters).
* @param out
* The output stream.
* @throws IOException
* if an I/O error occur while accessing the output stream.
*/
private static void writeNode(Node node, String indent, DataOutputStream out)
throws IOException {
String text;
switch (node.getNodeType()) {
case Node.DOCUMENT_NODE:
// Write the XML file signature.
out.write(StrUtil.getUTF8Bytes(XML_DECLARATION));
out.write(CRLF_BYTES);
// Iterate through each child nodes.
NodeList nodes = node.getChildNodes();
if (nodes != null) {
for (int i = 0; i < nodes.getLength(); i++) {
writeNode(nodes.item(i), "", out); //$NON-NLS-1$
}
}
break;
case Node.ELEMENT_NODE:
String name = node.getNodeName();
out.write(StrUtil.getUTF8Bytes(indent + "<" + name)); //$NON-NLS-1$
NamedNodeMap attrs = node.getAttributes();
for (int i = 0; i < attrs.getLength(); i++) {
Node attrNode = attrs.item(i);
out.write(StrUtil.getUTF8Bytes(" " + attrNode.getNodeName() //$NON-NLS-1$
+ "=\"" + escape(attrNode.getNodeValue()) + "\"")); //$NON-NLS-1$ //$NON-NLS-2$
}
out.write(StrUtil.getUTF8Bytes(">")); //$NON-NLS-1$
out.write(CRLF_BYTES);
// Iterate through each child nodes.
NodeList childNodes = node.getChildNodes();
if (childNodes != null) {
for (int i = 0; i < childNodes.getLength(); i++) {
writeNode(childNodes.item(i), indent, out);
}
}
out.write(StrUtil.getUTF8Bytes(indent + "</" + name + ">")); //$NON-NLS-1$ //$NON-NLS-2$
out.write(CRLF_BYTES);
break;
case Node.TEXT_NODE:
text = StrUtil.removeWhiteSpaceChars(node.getNodeValue());
if (text.length() > 0) {
out.write(StrUtil.getUTF8Bytes(escape(text)));
}
break;
case Node.CDATA_SECTION_NODE:
text = StrUtil.removeWhiteSpaceChars(node.getNodeValue());
if (text.length() > 0) {
out.write(StrUtil.getUTF8Bytes("<![CDATA[")); //$NON-NLS-1$
out.write(StrUtil.getUTF8Bytes(text));
out.write(StrUtil.getUTF8Bytes("]]>")); //$NON-NLS-1$
out.write(CRLF_BYTES);
}
break;
case Node.PROCESSING_INSTRUCTION_NODE:
out.write(StrUtil.getUTF8Bytes("<?" + node.getNodeName() //$NON-NLS-1$
+ " " + node.getNodeValue() + "?>")); //$NON-NLS-1$ //$NON-NLS-2$
out.write(CRLF_BYTES);
break;
case Node.ENTITY_REFERENCE_NODE:
out.write(StrUtil.getUTF8Bytes("&" + node.getNodeName() + ";")); //$NON-NLS-1$ //$NON-NLS-2$
break;
}
}
/**
* Returns the file location where the given SAX exception occurred.
*
* @param e
* The SAX parse exception.
* @return A string containing the file location where the exception
* occurred.
*/
public static String getLocationOfException(SAXParseException e) {
StringBuffer sb = new StringBuffer();
sb.append("row "); //$NON-NLS-1$
sb.append(e.getLineNumber());
sb.append(", col "); //$NON-NLS-1$
sb.append(e.getColumnNumber());
String systemId = e.getSystemId();
if (systemId != null) {
int index = systemId.lastIndexOf('/');
if (index != -1) {
systemId = systemId.substring(index + 1);
}
sb.append(" of XML document "); //$NON-NLS-1$
sb.append(systemId);
}
return sb.toString();
}
public static Document loadXml(File file) throws Exception {
DocumentBuilderFactory builderFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
return builder.parse(file);
}
public static Document loadXml(String xmlString) throws Exception {
DocumentBuilderFactory builderFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
ReaderInputStream istrem = new ReaderInputStream(new StringReader(xmlString), "UTF-8"); //$NON-NLS-1$
return builder.parse(istrem);
}
public static Document createDocument() throws Exception {
DocumentBuilderFactory builderFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
return builder.newDocument();
}
public static String toXmlString(Document doc) throws Exception {
DOMSource domSource = new DOMSource(doc);
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.transform(domSource, result);
writer.flush();
return writer.toString();
}
/**
* text of a leaf node, without child element
*
* @param tag
* @return String
*/
public static String getNodeText(Element tag) {
String text = tag.toString();
int i = text.indexOf(">"); //$NON-NLS-1$
int j = text.lastIndexOf("</"); //$NON-NLS-1$
if (i < 0 || j < 0 || j < i) {
return ""; //$NON-NLS-1$
}
return text.substring(i + 1, j);
}
public static String getChildText(Element tag, String childTagName) {
Element child = getFirstChild(tag, childTagName);
if (child != null) {
return getNodeText(child);
}
return ""; //$NON-NLS-1$
}
public static Element getFirstChild(Element tag, String childTagName) {
NodeList nodes = tag.getElementsByTagName(childTagName);
if (nodes == null || nodes.getLength() == 0) {
return null;
}
return (Element) nodes.item(0);
}
/**
* iterator of all the children of the element
*
* @param tag
* @return Iterator
*/
public static Iterator childIterator(Element tag) {
NodeList nodes = tag.getChildNodes();
// NodeList contains no Element nodes such as text nodes, ignore those
List<Node> elements = new ArrayList<Node>();
if (nodes != null) {
int size = nodes.getLength();
for (int i = 0; i < size; i++) {
Node node = nodes.item(i);
if (node instanceof Element) {
elements.add(node);
}
}
}
return elements.iterator();
}
private static class NodeIterator implements Iterator {
int currentIndex = -1;
int size = 0;
NodeList nodes = null;
public NodeIterator(NodeList nodes) {
this.nodes = nodes;
if (nodes != null)
size = nodes.getLength();
}
public void remove() {
// Do nothing, this is a readonly iterator.
}
public boolean hasNext() {
return currentIndex + 1 < size;
}
public Object next() {
if (hasNext()) {
return nodes.item(++currentIndex);
}
return null;
}
}
/**
* iterator of all the children of the element
*
* @param tag
* @return Iterator
*/
public static Iterator childIterator(Element tag, String childTagName) {
NodeList nodes = tag.getElementsByTagName(childTagName);
return new NodeIterator(nodes);
}
/**
* Gets the list of immediate child elements with the given tag name.
*
* @param element
* @param tagName
* @return list of {@link Element} objects
*/
public static List<Element> getChildElementsByTagName(Element element, String tagName) {
List<Element> elements = new ArrayList<Element>();
NodeList list = element.getChildNodes();
int size = list.getLength();
if(size > 0) {
for (int i = 0; i < size; i++) {
Node node = list.item(i);
if(node instanceof Element) {
Element e = (Element) node;
if(e.getTagName().equals(tagName)) {
elements.add(e);
}
}
}
}
return elements;
}
public static List<String> getChildTextsByTagName(Element element, String tagName) {
List<Element> elements = getChildElementsByTagName(element, tagName);
List <String> list = new ArrayList<String>();
for (Element e : elements) {
String textValue = e.getTextContent().trim();
if (textValue.length() != 0) {
list.add(textValue);
}
}
return list;
}
public static String getFirstChildTextByTagName(Element element, String tagName) {
Element e = getFirstChildElementByTagName(element, tagName);
return e == null ? null : e.getTextContent().trim();
}
/**
* Gets the first element with the given tag name in the immediate child elements.
*
* @param element
* @param tagName
* @return
*/
public static Element getFirstChildElementByTagName(Node element, String tagName) {
NodeList list = element.getChildNodes();
int size = list.getLength();
if(size > 0) {
for (int i = 0; i < size; i++) {
Node node = list.item(i);
if(node instanceof Element) {
Element e = (Element) node;
if(e.getTagName().equals(tagName)) {
return e;
}
}
}
}
return null;
}
public static String removeBOM(String xml) {
return xml.trim().replaceFirst("^([\\W]+)<", "<"); //$NON-NLS-1$ //$NON-NLS-2$
}
public static String elementToString(Element element) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
writeNode(element, " ", dos); //$NON-NLS-1$
return baos.toString();
}
}