001/**
002The contents of this file are subject to the Mozilla Public License Version 1.1 
003(the "License"); you may not use this file except in compliance with the License. 
004You may obtain a copy of the License at http://www.mozilla.org/MPL/ 
005Software distributed under the License is distributed on an "AS IS" basis, 
006WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
007specific language governing rights and limitations under the License. 
008
009The Original Code is "XMLUtils.java".  Description: 
010"XML utilities" 
011
012The Initial Developer of the Original Code is University Health Network. Copyright (C) 
0132001.  All Rights Reserved. 
014
015Contributor(s): ______________________________________. 
016
017Alternatively, the contents of this file may be used under the terms of the 
018GNU General Public License (the  "GPL"), in which case the provisions of the GPL are 
019applicable instead of those above.  If you wish to allow use of your version of this 
020file only under the terms of the GPL and not to allow others to use your version 
021of this file under the MPL, indicate your decision by deleting  the provisions above 
022and replace  them with the notice and other provisions required by the GPL License.  
023If you do not delete the provisions above, a recipient may use your version of 
024this file under either the MPL or the GPL. 
025 */
026package ca.uhn.hl7v2.util;
027
028import java.io.*;
029
030import org.slf4j.Logger;
031import org.slf4j.LoggerFactory;
032import org.w3c.dom.DOMConfiguration;
033import org.w3c.dom.DOMErrorHandler;
034import org.w3c.dom.DOMImplementation;
035import org.w3c.dom.Document;
036import org.w3c.dom.bootstrap.DOMImplementationRegistry;
037import org.w3c.dom.ls.DOMImplementationLS;
038import org.w3c.dom.ls.LSInput;
039import org.w3c.dom.ls.LSOutput;
040import org.w3c.dom.ls.LSResourceResolver;
041import org.w3c.dom.ls.LSSerializer;
042import org.xml.sax.InputSource;
043import org.xml.sax.SAXException;
044
045import javax.xml.parsers.DocumentBuilder;
046import javax.xml.parsers.DocumentBuilderFactory;
047import javax.xml.parsers.ParserConfigurationException;
048
049public class XMLUtils {
050    private static final Logger ourLog = LoggerFactory.getLogger(XMLUtils.class);
051
052    private static DOMImplementation IMPL;
053
054    @SuppressWarnings("unchecked")
055    public synchronized static <T> T getDOMImpl() {
056        if (IMPL == null) {
057            try {
058                DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
059                IMPL = registry.getDOMImplementation("LS 3.0");
060            } catch (Exception e) {
061                throw new RuntimeException(e);
062            }
063        }
064        return (T) IMPL;
065    }
066
067    @SuppressWarnings("unchecked")
068    public static Document parse(String s) {
069        return parseDocument(new InputSource(new StringReader(s)), false);
070    }
071
072    public static Document parse(String s, boolean validateIfSchema) {
073        return parseDocument(new InputSource(new StringReader(s)), validateIfSchema);
074    }
075
076    public static Document parse(InputStream s, boolean validateIfSchema) {
077        return parseDocument(new InputSource(s), validateIfSchema);
078    }
079
080    public static Document parseDocument(InputSource theInputSource, boolean theValidating) {
081        DocumentBuilder builder;
082        try {
083            DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
084            docBuilderFactory.setNamespaceAware(true);
085            docBuilderFactory.setXIncludeAware(false);
086            docBuilderFactory.setExpandEntityReferences(false);
087            docBuilderFactory.setValidating(theValidating);
088            try {
089                docBuilderFactory.setFeature(
090                        "http://apache.org/xml/features/disallow-doctype-decl", false);
091                docBuilderFactory.setFeature("http://xml.org/sax/features/external-general-entities", false);
092                docBuilderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-dtd-grammar", false);
093                docBuilderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
094                docBuilderFactory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
095            } catch (Exception e) {
096                ourLog.warn("Failed to set feature on XML parser: " + e.toString());
097            }
098
099            builder = docBuilderFactory.newDocumentBuilder();
100        } catch (ParserConfigurationException e) {
101            throw new RuntimeException(e);
102        }
103
104        try {
105            return builder.parse(theInputSource);
106        } catch (SAXException | IOException e) {
107            throw new RuntimeException(e);
108        }
109    }
110
111
112    public static void validate(Document d, String schema, DOMErrorHandler handler) {
113        DOMConfiguration config = d.getDomConfig();
114        config.setParameter("schema-type", "http://www.w3.org/2001/XMLSchema");
115        config.setParameter("validate", true);
116        config.setParameter("schema-location", schema);
117        config.setParameter("resource-resolver", new ClasspathResourceResolver());
118        config.setParameter("error-handler", handler);
119        d.normalizeDocument();
120    }
121
122    public static String serialize(Document document, boolean prettyPrint) {
123        DOMImplementationLS impl = getDOMImpl();
124        LSSerializer serializer = impl.createLSSerializer();
125        // document.normalizeDocument();
126        DOMConfiguration config = serializer.getDomConfig();
127        if (prettyPrint && config.canSetParameter("format-pretty-print", Boolean.TRUE)) {
128            config.setParameter("format-pretty-print", true);
129        }
130        config.setParameter("xml-declaration", true);        
131        LSOutput output = impl.createLSOutput();
132        output.setEncoding("UTF-8");
133        Writer writer = new StringWriter();
134        output.setCharacterStream(writer);
135        serializer.write(document, output);
136        return writer.toString();
137    }
138
139    public static Document emptyDocument(String title) {
140        DOMImplementation impl = getDOMImpl();
141        return impl.createDocument("urn:hl7-org:v2xml", title, null);
142    }
143
144    /**
145     * This is an implementation of LSResourceResolver that can resolve XML schemas from the
146     * classpath
147     */
148    private static class ClasspathResourceResolver implements LSResourceResolver {
149        private final DOMImplementationLS impl;
150
151        ClasspathResourceResolver() {
152            impl = getDOMImpl();
153        }
154
155        public LSInput resolveResource(String type, String namespaceURI, String publicId, String systemId,
156                String baseURI) {
157            LSInput lsInput = impl.createLSInput();
158            InputStream is = getClass().getResourceAsStream("/" + systemId);
159            if (is == null)
160                return null;
161            lsInput.setByteStream(is);
162            return lsInput;
163        }
164    }
165
166}