001: /*
002: * $Id: XMLHelper.java,v 1.4 2002/04/02 21:50:35 awason Exp $
003: *
004: * ===========================================================================
005: *
006: * The JGenerator Software License, Version 1.0
007: *
008: * Copyright (c) 2000 Dmitry Skavish (skavish@usa.net). All rights reserved.
009: *
010: * Redistribution and use in source and binary forms, with or without
011: * modification, are permitted provided that the following conditions are met:
012: *
013: * 1. Redistributions of source code must retain the above copyright
014: * notice, this list of conditions and the following disclaimer.
015: *
016: * 2. Redistributions in binary form must reproduce the above copyright
017: * notice, this list of conditions and the following disclaimer in
018: * the documentation and/or other materials provided with the
019: * distribution.
020: *
021: * 3. The end-user documentation included with the redistribution, if
022: * any, must include the following acknowlegement:
023: * "This product includes software developed by Dmitry Skavish
024: * (skavish@usa.net, http://www.flashgap.com/)."
025: * Alternately, this acknowlegement may appear in the software itself,
026: * if and wherever such third-party acknowlegements normally appear.
027: *
028: * 4. The name "The JGenerator" must not be used to endorse or promote
029: * products derived from this software without prior written permission.
030: * For written permission, please contact skavish@usa.net.
031: *
032: * 5. Products derived from this software may not be called "The JGenerator"
033: * nor may "The JGenerator" appear in their names without prior written
034: * permission of Dmitry Skavish.
035: *
036: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
037: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
038: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
039: * DISCLAIMED. IN NO EVENT SHALL DMITRY SKAVISH OR THE OTHER
040: * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
041: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
042: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
043: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
044: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
045: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
046: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
047: * SUCH DAMAGE.
048: *
049: */
050:
051: package org.openlaszlo.iv.flash.xml;
052:
053: import java.io.*;
054: import java.net.*;
055: import java.util.*;
056:
057: import java.io.FileInputStream;
058: import java.io.FileNotFoundException;
059: import java.util.Properties;
060:
061: import org.w3c.dom.*;
062: import org.w3c.dom.traversal.*;
063: import org.xml.sax.SAXException;
064: import org.xml.sax.InputSource;
065:
066: import javax.xml.parsers.*;
067: import javax.xml.transform.*;
068:
069: import org.openlaszlo.iv.flash.api.*;
070: import org.openlaszlo.iv.flash.url.*;
071: import org.openlaszlo.iv.flash.util.*;
072:
073: import org.openlaszlo.iv.flash.cache.*;
074:
075: import org.xml.sax.EntityResolver;
076: import org.xml.sax.InputSource;
077:
078: /**
079: * XMl Helper class.
080: * <P>
081: * Provides various methods for XML stuff
082: *
083: * @author Dmitry Skavish
084: */
085: public class XMLHelper {
086:
087: private static XMLFactory factory = XMLFactory.getFactory();
088:
089: /**
090: * Returns XMLFactory
091: *
092: * @return xml factory
093: */
094: public static XMLFactory getXMLFactory() {
095: return factory;
096: }
097:
098: /**
099: * Returns DocumentBuilder or null
100: *
101: * @return DocumentBuilder or null
102: */
103: public static DocumentBuilder getDocumentBuilder() {
104: try {
105: return factory.getDocumentBuilder();
106: } catch (ParserConfigurationException e) {
107: Log.logRB(e);
108: return null;
109: }
110: }
111:
112: /**
113: * Creates new empty xml document
114: *
115: * @return new empty xml document
116: */
117: public static Document newDocument() {
118: return getDocumentBuilder().newDocument();
119: }
120:
121: /**
122: * Parses input stream of some xml data into xml document.
123: *
124: * @param is xml input stream
125: * @return xml document
126: * @exception IOException
127: * @exception SAXException
128: */
129: public static Document parse(InputStream is) throws IOException,
130: SAXException {
131: return parse(new InputSource(is));
132: }
133:
134: /**
135: * Parses input source of some xml data into xml document.
136: *
137: * @param isrc xml input source
138: * @return xml document
139: * @exception IOException
140: * @exception SAXException
141: */
142: public static Document parse(InputSource isrc) throws IOException,
143: SAXException {
144: return getDocumentBuilder().parse(isrc);
145: }
146:
147: /**
148: * Parses xml document specified by url.
149: * <P>
150: * First tries to retrieve xml document from cache.
151: * If it is not cached then reads it, parses it and caches (if needed).
152: *
153: * @param url url to xml document
154: * @return xml document
155: * @exception IOException
156: * @exception SAXException
157: */
158: public static Document getDocument(IVUrl url) throws IOException,
159: SAXException {
160: Document doc = XMLCache.getXMLDocument(url);
161: if (doc != null)
162: return doc;
163: doc = parse(url.getInputStream());
164: XMLCache.addXMLDocument(url, doc);
165: return doc;
166: }
167:
168: /**
169: * Parses xml document specified by url and resolves it to one node.
170: * <P>
171: * First tries to retrieve xml document from cache.
172: * If it is not cached then reads it, parses it and caches (if needed).
173: * Then if there is no any xpath expression in url returns Document itself as a xml node.
174: * If there is some Xpath then evaluates this XPath to one xml node and returns it.
175: * <P>
176: * The url's format: <url itself>#<xpath expression which returns single node><BR>
177: * Example: <CODE>http://myserver.com/mydata.xml#/doc/item/firstNode</CODE>
178: *
179: * @param url url to xml document
180: * @return xml node
181: * @exception IOException
182: * @exception SAXException
183: */
184: public static Node getNode(IVUrl url) throws IOException,
185: SAXException {
186: Document doc = getDocument(url);
187: String ref = url.getRef();
188: if (ref == null)
189: return doc;
190: Node node;
191: try {
192: node = getXMLFactory().getXPathProcessor()
193: .selectSingleNode(ref, doc);
194: } catch (TransformerException e) {
195: throw new SAXException(e);
196: }
197: return node;
198: }
199:
200: }
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