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// Licensed to the Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE.txt file distributed with this work for
// additional information regarding copyright ownership. The ASF licenses this
// file to you 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.
//
// Portions of this code come from the Apache XML Project's Xerces 1.0.3 XML Parser
// (specifically, the functions escape and getEntityRef). Apache license applies:
//
// The Apache Software License, Version 1.1
//
// Copyright (c) 1999 The Apache Software Foundation. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other materials
// provided with the distribution.
//
// 3. The end-user documentation included with the redistribution, if any, must include
// the following acknowledgment:
//
// "This product includes software developed by the Apache Software Foundation (http://www.apache.org/)."
//
// Alternately, this acknowledgment may appear in the software itself,
// if and wherever such third-party acknowledgments normally appear.
//
// 4. The names "Xerces" and "Apache Software Foundation" must not be used to endorse or
// promote products derived from this software without prior written permission. For
// written permission, please contact [email protected].
//
// 5. Products derived from this software may not be called "Apache", nor may "Apache"
// appear in their name, without prior written permission of the Apache Software
// Foundation.
//
// THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING,
// BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
// ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// $Id: XML.java,v 1.2 2005-05-01 22:49:55 cmattmann Exp $
package org.apache.oodt.commons.util;
import java.io.*;
import java.util.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.TransformerException;
import javax.xml.transform.OutputKeys;
/** XML services.
*
* This class provides several XML convenience services and encapsulates the underlying
* XML implementation, allowing it to vary without impacting developers.
*
* @author Kelly
*/
public class XML {
private static DocumentBuilder getStandardDocumentBuilder() {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setCoalescing(false);
factory.setExpandEntityReferences(false);
factory.setIgnoringComments(false);
factory.setIgnoringElementContentWhitespace(true);
factory.setNamespaceAware(true);
factory.setValidating(true);
return factory.newDocumentBuilder();
} catch (ParserConfigurationException ex) {
throw new IllegalStateException("Unexpected ParserConfigurationException: " + ex.getMessage());
}
}
/** Get the DOM implementation.
*
* @return The DOM implementation.
*/
public static DOMImplementation getDOMImplementation() {
return getStandardDocumentBuilder().getDOMImplementation();
}
/** Create a DOM document.
*
* @return A new DOM document.
*/
public static Document createDocument() {
return getStandardDocumentBuilder().newDocument();
}
/** Create a DOM parser.
*
* This method creates a new DOM parser that has validation turned on and
* ignorable whitespace not included, and has a default error handler that prints
* error messages and warnings to the standard error stream.
*
* @return A new DOM parser.
*/
public static DOMParser createDOMParser() {
DocumentBuilder builder = getStandardDocumentBuilder();
builder.setEntityResolver(ENTERPRISE_ENTITY_RESOLVER);
builder.setErrorHandler(new ErrorHandler() {
public void error(SAXParseException ex) {
System.err.println("Parse error: " + ex.getMessage());
ex.printStackTrace();
}
public void warning(SAXParseException ex) {
System.err.println("Parse warning: " + ex.getMessage());
}
public void fatalError(SAXParseException ex) {
System.err.println("Fatal parse error: " + ex.getMessage());
ex.printStackTrace();
}
});
return new DOMParser(builder);
}
/** Create a SAX parser.
*
* This method creates a new, default SAX parser. It's set up with a default
* error handler that just prints messages to the standard error stream.
*
* @return A new SAX parser.
*/
public static SAXParser createSAXParser() {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setNamespaceAware(false);
factory.setValidating(false);
javax.xml.parsers.SAXParser saxParser = factory.newSAXParser();
saxParser.getXMLReader().setEntityResolver(ENTERPRISE_ENTITY_RESOLVER);
saxParser.getXMLReader().setErrorHandler(new ErrorHandler() {
public void error(SAXParseException ex) {
System.err.println("Parse error: " + ex.getMessage());
}
public void warning(SAXParseException ex) {
System.err.println("Parse warning: " + ex.getMessage());
}
public void fatalError(SAXParseException ex) {
System.err.println("Fatal parse error: " + ex.getMessage());
}
});
SAXParser p = new SAXParser(saxParser);
return p;
} catch (ParserConfigurationException ex) {
throw new IllegalStateException("Unexpected ParserConfigurationException: " + ex.getMessage());
} catch (SAXException ex) {
throw new IllegalStateException("Unexpected SAXException: " + ex.getMessage());
}
}
/** Serialize an XML DOM document into a String.
*
* This method takes a DOM document and pretty-prints (or pretty-serializes, in
* XML parlance) it into a string.
*
* @param doc The document.
* @param omitXMLDeclaration True if we should omit the XML declaration, false to keep the XML declaration.
* @return The pretty-serialized, stringified, document.
*/
public static String serialize(Document doc, boolean omitXMLDeclaration) {
StringWriter writer = new StringWriter();
try {
serialize(doc, writer, omitXMLDeclaration);
} catch (IOException cantHappen) {}
return writer.getBuffer().toString();
}
/** Serialize an XML DOM document into a String.
*
* This method takes a DOM document and pretty-prints (or pretty-serializes, in
* XML parlance) it into a string.
*
* @param doc The document.
* @return The pretty-serialized, stringified, document.
*/
public static String serialize(Document doc) {
return serialize(doc, /*omitXMLDeclaration*/false);
}
/** Serialize an XML DOM document into a writer.
*
* This method takes a DOM document and pretty-prints (or pretty-serializes, in
* XML parlance) it into a writer.
*
* @param doc The document.
* @param writer Where to write it.
* @param omitXMLDeclaration True if we should omit the XML declaration, false to keep the XML declaration.
* @throws IOException If an I/O error occurs.
*/
public static void serialize(Document doc, Writer writer, boolean omitXMLDeclaration) throws IOException {
try {
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
//update 05/01/2005
//author: Chris Mattmann
//set properties to pretty print
//and also to include the DOCTYPE when serializing the XML
//only set this if it's not null else we get a nice NullPointerException
if(doc.getDoctype().getPublicId() != null){
transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, doc.getDoctype().getPublicId());
}
//only set this if it's not null else we get a nice NullPointerException
if(doc.getDoctype().getSystemId() != null){
transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId());
}
transformer.setOutputProperty(OutputKeys.INDENT,"yes");
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(writer);
transformer.transform(source, result);
} catch (TransformerConfigurationException ex) {
throw new IllegalStateException("Unexpected TransformerConfigurationException: " + ex.getMessage());
} catch (TransformerException ex) {
throw new IllegalStateException("Unexpected TransformerException: " + ex.getMessage());
}
}
/** Serialize an XML DOM document into a writer.
*
* This method takes a DOM document and pretty-prints (or pretty-serializes, in
* XML parlance) it into a writer.
*
* @param doc The document.
* @param writer Where to write it.
* @throws IOException If an I/O error occurs.
*/
public static void serialize(Document doc, Writer writer) throws IOException {
serialize(doc, writer, /*omitXMLDeclaration*/false);
}
/** Parse the given XML document into a DOM tree.
*
* @param inputSource The XML document to parse.
* @return A DOM tree for the given XML document.
* @throws SAXException If a parse error occurs.
* @throws IOException If an I/O error occurs.
*/
public static Document parse(InputSource inputSource) throws SAXException, IOException {
DOMParser parser = XML.createDOMParser();
parser.parse(inputSource);
return parser.getDocument();
}
/** Parse the given XML document into a DOM tree.
*
* @param string The XML document to parse.
* @return A DOM tree for the given XML document.
* @throws SAXException If a parse error occurs.
*/
public static Document parse(String string) throws SAXException {
Document doc = null;
try {
DOMParser parser = XML.createDOMParser();
StringReader reader = new StringReader(string);
InputSource inputSource = new InputSource(reader);
doc = parse(inputSource);
reader.close();
} catch (IOException cantHappen) {
cantHappen.printStackTrace();
throw new RuntimeException("I/O exception " + cantHappen.getClass().getName()
+ " can NOT have happened, yet it did! Message: " + cantHappen.getMessage());
}
return doc;
}
/** Parse the given XML document into a DOM tree.
*
* @param reader The XML document to parse.
* @return A DOM tree for the given XML document.
* @throws SAXException If a parse error occurs.
* @throws IOException If an I/O error occurs.
*/
public static Document parse(Reader reader) throws SAXException, IOException {
return parse(new InputSource(reader));
}
/** Parse the given XML document into a DOM tree.
*
* @param inputStream The XML document to parse.
* @return A DOM tree for the given XML document.
* @throws SAXException If a parse error occurs.
* @throws IOException If an I/O error occurs.
*/
public static Document parse(InputStream inputStream) throws SAXException, IOException {
return parse(new InputStreamReader(inputStream));
}
/** Add a repeating child element with text from the given collection to the given node.
*
* For example, if values is a {@link java.util.List} with strings items
* "a", "b", and "c", and name is "value", then the XML document will
* have
* <value>a</value>
* <value>b</value>
* <value>c</value>
* appended to node.
*
* @param node Node to which to add child elements.
* @param name Name to give each child element.
* @param values Collection of values to assign to each child element, in iterator order.
* @throws DOMException If a DOM error occurs.
*/
public static void add(Node node, String name, Collection values) throws DOMException {
for (Iterator i = values.iterator(); i.hasNext();)
add(node, name, i.next());
}
/** Add a child element with the given text to the given element.
*
* This method modifies your DOM tree so that
* <node>
* ...
* </node>
* becomes
* <node>
* ...
* <name>text>/name>
* </node>
*
* Adding a null name does nothing. Adding null text
* won't add the element.
*
* @param node Node to which to add a child element.
* @param name Name of the child element to add to node.
* @param text What text the text-node child the child element named name should have. If null,
* nothing happens.
* @throws DOMException If a DOM error occurs.
*/
public static void addNonNull(Node node, String name, String text) throws DOMException {
if (text == null) return;
add(node, name, text);
}
/** Add a child element with the given text to the given element.
*
* This method modifies your DOM tree so that
* <node>
* ...
* </node>
* becomes
* <node>
* ...
* <name>text>/name>
* </node>
*
* Adding a null name does nothing. Adding null text
* results in an empty name tag.
*
* @param node Node to which to add a child element.
* @param name Name of the child element to add to node.
* @param text What text the text-node child the child element named name should have.
* @throws DOMException If a DOM error occurs.
*/
public static void add(Node node, String name, String text) throws DOMException {
if (name == null) return;
if (node == null) throw new IllegalArgumentException("Can't add to a null node");
Document doc = node.getOwnerDocument();
Element element = doc.createElement(name);
if (text != null) element.appendChild(doc.createTextNode(text));
node.appendChild(element);
}
/** Add a child element with the string representation of the given
* object to the given node.
*
* This method modifies your DOM tree so that
* <node>
* ...
* </node>
* becomes
* <node>
* ...
* <name>string-rep>/name>
* </node>
*
* Adding a null name does nothing. Adding null object
* results in an empty name tag.
*
* @param node Node to which to add a child element.
* @param name Name of the child element to add to node.
* @param object The string representation of the object to have as the text-node
* child the child element named name.
* @throws DOMException If a DOM error occurs.
*/
public static void add(Node node, String name, Object object) throws DOMException {
add(node, name, object == null? null : object.toString());
}
/** Get unwrapped text from the given DOM node
*
* This method unwraps any wrapped text. For example, if the document contains
* <node>Hello, world. This is
* my first document.
* </node>
* then the node's unwrapped text is
* Hello, world. This is my first document.
* while the {@link #text} method would return the wrapped value
* Hello, world. This is
* my first document.
*
* In other words, it collects the text nodes under the given node and replaces
* strings of newlines and spaces with a single space. Unwrapping a null node
* returns a null string.
*
* @param node The node.
* @return The text in its children, unwrapped.
*/
public static String unwrappedText(Node node) {
if (node == null) return null;
StringBuffer buffer = new StringBuffer();
StringBuffer wrapped = new StringBuffer(text1(node, buffer));
boolean newline = false;
for (int i = 0; i < wrapped.length(); ++i) {
if (newline == false) {
if (wrapped.charAt(i) == '\n') {
newline = true;
wrapped.setCharAt(i, ' ');
}
} else {
if (Character.isWhitespace(wrapped.charAt(i))) {
wrapped.deleteCharAt(i);
--i;
} else
newline = false;
}
}
return wrapped.toString().trim();
}
/** Get the text from the given DOM node.
*
* Getting text from a null node gives you a null string.
*
* @param node The node.
* @return The text in its children.
*/
public static String text(Node node) {
// [ return text(node) ]
StringBuffer buffer = new StringBuffer();
return text1(node, buffer);
}
/** Dump the structure of the DOM tree rooted at the given node to the given writer.
*
* This outputs the tree structure including the type of each node, its name, and
* its value. Note that for many nodes, the name isn't useful (the name of text
* nodes, for example, is #text), and for many nodes, the value is
* null.
*
* @param writer The writer to which write the tree structure.
* @param node The tree to output.
*/
public static void dump(PrintWriter writer, Node node) {
dump(writer, node, 0);
}
/** Remove all comments from the given document node's subtree.
*
* @param node Node from which to search for comments to nuke.
*/
public static void removeComments(Node node) {
List commentNodes = new ArrayList();
findCommentNodes(commentNodes, node);
for (Iterator i = commentNodes.iterator(); i.hasNext();) {
Node commentNode = (Node) i.next();
commentNode.getParentNode().removeChild(commentNode);
}
}
/** The resolver for entities for the JPL enterprise. */
public static final EntityResolver ENTERPRISE_ENTITY_RESOLVER = new EnterpriseEntityResolver();
/** An empty XML DOM document. This is handy for some basic operations, and for
* fetching the DOM implementation.
*/
public static final Document EMPTY_DOCUMENT = org.apache.oodt.commons.util.XML.createDocument();
/** Identifies the last printable character in the Unicode range that is supported
* by the encoding used with this serializer. For 8-bit encodings this will be either
* 0x7E or 0xFF. For 16-bit encodings this will be 0xFFFF. Characters that are not
* printable will be escaped using character references.
*
*
Taken from Xerces 1.0.3. Apache license applies; see source code for
* license.
*
*/
private static int LAST_PRINTABLE = 0x7E;
/** Escapes a string so it may be printed as text content or attribute value. Non
* printable characters are escaped using character references. Where the format
* specifies a deault entity reference, that reference is used
* (e.g. <).
*
*
Taken from Xerces 1.0.3. Apache license applies; see source code for
* license.
*
* @param source The string to escape
* @return The escaped string
*/
public static String escape(String source) {
StringBuffer result;
int i;
char ch;
String charRef;
result = new StringBuffer(source.length());
for (i = 0; i < source.length(); ++i) {
ch = source.charAt(i);
// If the character is not printable, print as character
// reference. Non printables are below ASCII space but not tab or
// line terminator, ASCII delete, or above a certain Unicode
// threshold.
if ((ch < ' ' && ch != '\t' && ch != '\n' && ch != '\r') || ch > LAST_PRINTABLE || ch == 0xF7)
result.append("&#").append(Integer.toString(ch)).append(';');
else {
// If there is a suitable entity reference for this
// character, print it. The list of available entity
// references is almost but not identical between XML and
// HTML.
charRef = getEntityRef(ch);
if (charRef == null) result.append(ch);
else result.append('&').append(charRef).append(';');
}
}
return result.toString();
}
/** Find all comment nodes under the given node and add them to the given list.
*
* @param list List to add to.
* @param node Node to search.
*/
private static void findCommentNodes(List list, Node node) {
if (node.getNodeType() == Node.COMMENT_NODE)
list.add(node);
else {
NodeList children = node.getChildNodes();
for (int i = 0; i < children.getLength(); ++i) {
findCommentNodes(list, children.item(i));
}
}
}
/** Get the entity reference for the given character.
*
* Taken from Xerces 1.0.3; see source code for license.
*/
private static String getEntityRef(char ch) {
// Encode special XML characters into the equivalent character references.
// These five are defined by default for all XML documents.
switch (ch) {
case '<': return "lt";
case '>': return "gt";
case '"': return "quot";
case '\'': return "apos";
case '&': return "amp";
}
return null;
}
/** Get the text from the child node using the given buffer.
*
* @param node The node.
* @param buffer The buffer to use.
* @return The text.
*/
private static String text1(Node node, StringBuffer buffer) {
for (Node ch = node.getFirstChild(); ch != null; ch = ch.getNextSibling()) {
if (ch.getNodeType() == Node.ELEMENT_NODE || ch.getNodeType() == Node.ENTITY_REFERENCE_NODE)
buffer.append(text(ch));
else if (ch.getNodeType() == Node.TEXT_NODE)
buffer.append(ch.getNodeValue());
}
return buffer.toString();
}
/** Dump the structure of the DOM tree rooted at the given node to the given writer,
* indenting the contents.
*
* @param indentAmt The number of spaces to indent the output of this node;
* children are indented two more than this amount.
* @param writer The writer to which write the tree structure.
* @param node The tree to output.
*/
private static void dump(PrintWriter writer, Node node, int indentAmt) {
for (int i = 0; i < indentAmt; ++i)
writer.print(' ');
writer.println(typeOf(node) + "(" + node.getNodeName() + ", " + node.getNodeValue() + ")");
NodeList children = node.getChildNodes();
for (int i = 0; i < children.getLength(); ++i)
dump(writer, children.item(i), indentAmt + 2);
}
/** Return a human-readable representation of the type of the given node.
*
* For example, an attribute node returns Attribute, while an element
* node returns Element.
*
* @param node The node.
* @return The name of the node's type.
*/
private static String typeOf(Node node) {
switch (node.getNodeType()) {
case Node.ATTRIBUTE_NODE: return "Attribute";
case Node.CDATA_SECTION_NODE: return "CDATA-Section";
case Node.COMMENT_NODE: return "Comment";
case Node.DOCUMENT_FRAGMENT_NODE: return "Document-Fragment";
case Node.DOCUMENT_NODE: return "Document";
case Node.DOCUMENT_TYPE_NODE: return "Document-Type";
case Node.ELEMENT_NODE: return "Element";
case Node.ENTITY_NODE: return "Entity";
case Node.ENTITY_REFERENCE_NODE: return "Entity-Ref";
case Node.NOTATION_NODE: return "Notation";
case Node.PROCESSING_INSTRUCTION_NODE: return "Proc-Instr";
case Node.TEXT_NODE: return "Text";
default: return "Unknown!";
}
}
}