1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.bind.v2.runtime.output;
  27 
  28 import java.io.IOException;
  29 import java.io.Writer;
  30 import java.lang.reflect.Constructor;
  31 
  32 import javax.xml.stream.XMLStreamException;
  33 import javax.xml.stream.XMLStreamWriter;
  34 
  35 import com.sun.xml.internal.bind.marshaller.CharacterEscapeHandler;
  36 import com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl;
  37 import com.sun.xml.internal.bind.v2.runtime.XMLSerializer;
  38 

  39 import org.xml.sax.SAXException;
  40 
  41 /**
  42  * {@link XmlOutput} that writes to StAX {@link XMLStreamWriter}.
  43  * <p>
  44  * TODO:
  45  * Finding the optimized FI implementations is a bit hacky and not very
  46  * extensible. Can we use the service provider mechanism in general for
  47  * concrete implementations of XmlOutputAbstractImpl.
  48  *
  49  * @author Kohsuke Kawaguchi
  50  */
  51 public class XMLStreamWriterOutput extends XmlOutputAbstractImpl {
  52 
  53     /**
  54      * Creates a new {@link XmlOutput} from a {@link XMLStreamWriter}.
  55      * This method recognizes an FI StAX writer.
  56      */
  57     public static XmlOutput create(XMLStreamWriter out, JAXBContextImpl context, CharacterEscapeHandler escapeHandler) {
  58         // try optimized path
  59         final Class writerClass = out.getClass();
  60         if (writerClass==FI_STAX_WRITER_CLASS) {
  61             try {
  62                 return FI_OUTPUT_CTOR.newInstance(out, context);
  63             } catch (Exception e) {
  64             }
  65         }
  66         if (STAXEX_WRITER_CLASS!=null && STAXEX_WRITER_CLASS.isAssignableFrom(writerClass)) {
  67             try {
  68                 return STAXEX_OUTPUT_CTOR.newInstance(out);
  69             } catch (Exception e) {
  70             }
  71         }
  72 
  73         CharacterEscapeHandler xmlStreamEscapeHandler = escapeHandler != null ?
  74                 escapeHandler : NewLineEscapeHandler.theInstance;
  75 
  76         // otherwise the normal writer.
  77         return new XMLStreamWriterOutput(out, xmlStreamEscapeHandler);
  78     }
  79 
  80 
  81     private final XMLStreamWriter out;
  82 
  83     private final CharacterEscapeHandler escapeHandler;
  84 
  85     private final XmlStreamOutWriterAdapter writerWrapper;
  86 
  87     protected final char[] buf = new char[256];
  88 
  89     protected XMLStreamWriterOutput(XMLStreamWriter out, CharacterEscapeHandler escapeHandler) {
  90         this.out = out;
  91         this.escapeHandler = escapeHandler;
  92         this.writerWrapper = new XmlStreamOutWriterAdapter(out);
  93     }
  94 
  95     // not called if we are generating fragments
  96     @Override
  97     public void startDocument(XMLSerializer serializer, boolean fragment, int[] nsUriIndex2prefixIndex, NamespaceContextImpl nsContext) throws IOException, SAXException, XMLStreamException {
  98         super.startDocument(serializer, fragment,nsUriIndex2prefixIndex,nsContext);
  99         if(!fragment)
 100             out.writeStartDocument();
 101     }
 102 
 103     @Override
 104     public void endDocument(boolean fragment) throws IOException, SAXException, XMLStreamException {
 105         if(!fragment) {
 106             out.writeEndDocument();
 107             out.flush();
 108         }
 109         super.endDocument(fragment);
 110     }
 111 
 112     public void beginStartTag(int prefix, String localName) throws IOException, XMLStreamException {
 113         out.writeStartElement(
 114             nsContext.getPrefix(prefix),
 115             localName,
 116             nsContext.getNamespaceURI(prefix));
 117 
 118         NamespaceContextImpl.Element nse = nsContext.getCurrent();
 119         if(nse.count()>0) {
 120             for( int i=nse.count()-1; i>=0; i-- ) {
 121                 String uri = nse.getNsUri(i);
 122                 if(uri.length()==0 && nse.getBase()==1)
 123                     continue;   // no point in definint xmlns='' on the root
 124                 out.writeNamespace(nse.getPrefix(i),uri);
 125             }
 126         }
 127     }
 128 
 129     public void attribute(int prefix, String localName, String value) throws IOException, XMLStreamException {
 130         if(prefix==-1)
 131             out.writeAttribute(localName,value);
 132         else
 133             out.writeAttribute(
 134                     nsContext.getPrefix(prefix),
 135                     nsContext.getNamespaceURI(prefix),
 136                     localName, value);
 137     }
 138 
 139     public void endStartTag() throws IOException, SAXException {
 140         // noop
 141     }
 142 
 143     public void endTag(int prefix, String localName) throws IOException, SAXException, XMLStreamException {
 144         out.writeEndElement();
 145     }
 146 
 147     public void text(String value, boolean needsSeparatingWhitespace) throws IOException, SAXException, XMLStreamException {
 148         if(needsSeparatingWhitespace)
 149             out.writeCharacters(" ");
 150         escapeHandler.escape(value.toCharArray(), 0, value.length(), false, writerWrapper);
 151     }
 152 
 153     public void text(Pcdata value, boolean needsSeparatingWhitespace) throws IOException, SAXException, XMLStreamException {
 154         if(needsSeparatingWhitespace)
 155             out.writeCharacters(" ");
 156 
 157         int len = value.length();
 158         if(len <buf.length) {
 159             value.writeTo(buf,0);
 160             out.writeCharacters(buf,0,len);
 161         } else {
 162             out.writeCharacters(value.toString());
 163         }
 164     }
 165 
 166     /**
 167      * Reference to FI's XMLStreamWriter class, if FI can be loaded.
 168      */
 169     private static final Class FI_STAX_WRITER_CLASS = initFIStAXWriterClass();
 170     private static final Constructor<? extends XmlOutput> FI_OUTPUT_CTOR = initFastInfosetOutputClass();
 171 
 172     private static Class initFIStAXWriterClass() {
 173         try {
 174             Class<?> llfisw = Class.forName("com.sun.xml.internal.org.jvnet.fastinfoset.stax.LowLevelFastInfosetStreamWriter");
 175             Class<?> sds = Class.forName("com.sun.xml.internal.fastinfoset.stax.StAXDocumentSerializer");
 176             // Check if StAXDocumentSerializer implements LowLevelFastInfosetStreamWriter
 177             if (llfisw.isAssignableFrom(sds))
 178                 return sds;
 179             else
 180                 return null;
 181         } catch (Throwable e) {
 182             return null;
 183         }
 184     }
 185 
 186     private static Constructor<? extends XmlOutput> initFastInfosetOutputClass() {
 187         try {
 188             if (FI_STAX_WRITER_CLASS == null)
 189                 return null;
 190             Class c = Class.forName("com.sun.xml.internal.bind.v2.runtime.output.FastInfosetStreamWriterOutput");
 191             return c.getConstructor(FI_STAX_WRITER_CLASS, JAXBContextImpl.class);
 192         } catch (Throwable e) {
 193             return null;
 194         }
 195     }
 196 
 197     //
 198     // StAX-ex
 199     //
 200     private static final Class STAXEX_WRITER_CLASS = initStAXExWriterClass();
 201     private static final Constructor<? extends XmlOutput> STAXEX_OUTPUT_CTOR = initStAXExOutputClass();
 202 
 203     private static Class initStAXExWriterClass() {
 204         try {
 205             return Class.forName("com.sun.xml.internal.org.jvnet.staxex.XMLStreamWriterEx");
 206         } catch (Throwable e) {
 207             return null;
 208         }
 209     }
 210 
 211     private static Constructor<? extends XmlOutput> initStAXExOutputClass() {
 212         try {
 213             Class c = Class.forName("com.sun.xml.internal.bind.v2.runtime.output.StAXExStreamWriterOutput");
 214             return c.getConstructor(STAXEX_WRITER_CLASS);
 215         } catch (Throwable e) {
 216             return null;
 217         }
 218     }
 219 
 220     /**
 221      * Performs character escaping only for new lines.
 222      */
 223     private static class NewLineEscapeHandler implements CharacterEscapeHandler {
 224 
 225         public static final NewLineEscapeHandler theInstance = new NewLineEscapeHandler();
 226 
 227         @Override
 228         public void escape(char[] ch, int start, int length, boolean isAttVal, Writer out) throws IOException {
 229             int limit = start+length;
 230             int lastEscaped = start;
 231             for (int i = start; i < limit; i++) {
 232                 char c = ch[i];
 233                 if (c == '\r' || c == '\n') {
 234                     if (i != lastEscaped) {
 235                         out.write(ch, lastEscaped, i - lastEscaped);
 236                     }
 237                     lastEscaped = i + 1;
 238                     if (out instanceof XmlStreamOutWriterAdapter) {
 239                         try {
 240                             ((XmlStreamOutWriterAdapter)out).writeEntityRef("#x" + Integer.toHexString(c));
 241                         } catch (XMLStreamException e) {
 242                             throw new IOException("Error writing xml stream", e);
 243                         }
 244                     } else {
 245                         out.write("&#x");
 246                         out.write(Integer.toHexString(c));
 247                         out.write(';');
 248                     }
 249                 }
 250             }
 251 
 252             if (lastEscaped != limit) {
 253                 out.write(ch, lastEscaped, length - lastEscaped);
 254             }
 255         }
 256     }
 257 
 258     private static final class XmlStreamOutWriterAdapter extends Writer {
 259 
 260         private final XMLStreamWriter writer;
 261 
 262         private XmlStreamOutWriterAdapter(XMLStreamWriter writer) {
 263             this.writer = writer;
 264         }
 265 
 266         @Override
 267         public void write(char[] cbuf, int off, int len) throws IOException {
 268             try {
 269                 writer.writeCharacters(cbuf, off, len);
 270             } catch (XMLStreamException e) {
 271                 throw new IOException("Error writing XML stream", e);
 272             }
 273         }
 274 
 275         public void writeEntityRef(String entityReference) throws XMLStreamException {
 276             writer.writeEntityRef(entityReference);
 277         }
 278 
 279         @Override
 280         public void flush() throws IOException {
 281             try {
 282                 writer.flush();
 283             } catch (XMLStreamException e) {
 284                 throw new IOException("Error flushing XML stream", e);
 285             }
 286         }
 287 
 288         @Override
 289         public void close() throws IOException {
 290             try {
 291                 writer.close();
 292             } catch (XMLStreamException e) {
 293                 throw new IOException("Error closing XML stream", e);
 294             }
 295         }
 296     }
 297 }
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