incrementalsaxsource_xerces.java

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  {
    // Not supported by all SAX2 parsers but should work in Xerces:
    try 
    {
      // Typecast required in Xerces2; SAXParser doesn't inheret XMLReader
      // %OPT% Cast at asignment?
      ((XMLReader)fIncrementalParser).setProperty("http://xml.org/sax/properties/lexical-handler",
                                     handler);
    }
    catch(org.xml.sax.SAXNotRecognizedException e)
    {
      // Nothing we can do about it
    }
    catch(org.xml.sax.SAXNotSupportedException e)
    {
      // Nothing we can do about it
    }
  }
  
  // Register handler directly with the incremental parser
  public void setDTDHandler(org.xml.sax.DTDHandler handler)
  {
    // Typecast required in Xerces2; SAXParser doesn't inheret XMLReader
    // %OPT% Cast at asignment?
    ((XMLReader)fIncrementalParser).setDTDHandler(handler);
  }

  //================================================================
  /** startParse() is a simple API which tells the IncrementalSAXSource
   * to begin reading a document.
   *
   * @throws SAXException is parse thread is already in progress
   * or parsing can not be started.
   * */
  public void startParse(InputSource source) throws SAXException
  {
    if (fIncrementalParser==null)
      throw new SAXException(XMLMessages.createXMLMessage(XMLErrorResources.ER_STARTPARSE_NEEDS_SAXPARSER, null)); //"startParse needs a non-null SAXParser.");
    if (fParseInProgress)
      throw new SAXException(XMLMessages.createXMLMessage(XMLErrorResources.ER_STARTPARSE_WHILE_PARSING, null)); //"startParse may not be called while parsing.");

    boolean ok=false;

    try
    {
      ok = parseSomeSetup(source);
    }
    catch(Exception ex)
    {
      throw new SAXException(ex);
    }
    
    if(!ok)
      throw new SAXException(XMLMessages.createXMLMessage(XMLErrorResources.ER_COULD_NOT_INIT_PARSER, null)); //"could not initialize parser with");
  }

  
  /** deliverMoreNodes() is a simple API which tells the coroutine
   * parser that we need more nodes.  This is intended to be called
   * from one of our partner routines, and serves to encapsulate the
   * details of how incremental parsing has been achieved.
   *
   * @param parsemore If true, tells the incremental parser to generate
   * another chunk of output. If false, tells the parser that we're
   * satisfied and it can terminate parsing of this document.
   * @return Boolean.TRUE if the CoroutineParser believes more data may be available
   * for further parsing. Boolean.FALSE if parsing ran to completion.
   * Exception if the parser objected for some reason.
   * */
  public Object deliverMoreNodes (boolean parsemore)
  {
    if(!parsemore)
    {
      fParseInProgress=false;
      return Boolean.FALSE;
    }

    Object arg;
    try {
      boolean keepgoing = parseSome();
      arg = keepgoing ? Boolean.TRUE : Boolean.FALSE;
    } catch (SAXException ex) {
      arg = ex;
    } catch (IOException ex) {
      arg = ex;
    } catch (Exception ex) {
      arg = new SAXException(ex);
    }
    return arg;
  }
	
	// Private methods -- conveniences to hide the reflection details
	private boolean parseSomeSetup(InputSource source) 
		throws SAXException, IOException, IllegalAccessException, 
					 java.lang.reflect.InvocationTargetException,
					 java.lang.InstantiationException
	{
		if(fConfigSetInput!=null)
		{
			// Obtain input from SAX inputSource object, construct XNI version of
			// that object. Logic adapted from Xerces2.
			Object[] parms1={source.getPublicId(),source.getSystemId(),null};
			Object xmlsource=fConfigInputSourceCtor.newInstance(parms1);
			Object[] parmsa={source.getByteStream()};
			fConfigSetByteStream.invoke(xmlsource,parmsa);
			parmsa[0]=source.getCharacterStream();
			fConfigSetCharStream.invoke(xmlsource,parmsa);
			parmsa[0]=source.getEncoding();
			fConfigSetEncoding.invoke(xmlsource,parmsa);

			// Bugzilla5272 patch suggested by Sandy Gao.
			// Has to be reflection to run with Xerces2
			// after compilation against Xerces1. or vice
			// versa, due to return type mismatches.
			Object[] noparms=new Object[0];
			fReset.invoke(fIncrementalParser,noparms);
			
			parmsa[0]=xmlsource;
			fConfigSetInput.invoke(fPullParserConfig,parmsa);
			
			// %REVIEW% Do first pull. Should we instead just return true?
			return parseSome();
		}
		else
		{
			Object[] parm={source};
			Object ret=fParseSomeSetup.invoke(fIncrementalParser,parm);
			return ((Boolean)ret).booleanValue();
		}
	}
//  Would null work???
    private static final Object[] noparms=new Object[0];
    private static final Object[] parmsfalse={Boolean.FALSE};
    private boolean parseSome()
		throws SAXException, IOException, IllegalAccessException,
					 java.lang.reflect.InvocationTargetException
	{
		// Take next parsing step, return false iff parsing complete:
		if(fConfigSetInput!=null)
		{
			Object ret=(Boolean)(fConfigParse.invoke(fPullParserConfig,parmsfalse));
			return ((Boolean)ret).booleanValue();
		}
		else
		{
			Object ret=fParseSome.invoke(fIncrementalParser,noparms);
			return ((Boolean)ret).booleanValue();
		}
	}
	

  //================================================================
  /** Simple unit test. Attempt coroutine parsing of document indicated
   * by first argument (as a URI), report progress.
   */
  public static void _main(String args[])
  {
    System.out.println("Starting...");

    CoroutineManager co = new CoroutineManager();
    int appCoroutineID = co.co_joinCoroutineSet(-1);
    if (appCoroutineID == -1)
    {
      System.out.println("ERROR: Couldn't allocate coroutine number.\n");
      return;
    }
    IncrementalSAXSource parser=
      createIncrementalSAXSource();

    // Use a serializer as our sample output
    com.sun.org.apache.xml.internal.serialize.XMLSerializer trace;
    trace=new com.sun.org.apache.xml.internal.serialize.XMLSerializer(System.out,null);
    parser.setContentHandler(trace);
    parser.setLexicalHandler(trace);

    // Tell coroutine to begin parsing, run while parsing is in progress

    for(int arg=0;arg<args.length;++arg)
    {
      try
      {
        InputSource source = new InputSource(args[arg]);
        Object result=null;
        boolean more=true;
        parser.startParse(source);
        for(result = parser.deliverMoreNodes(more);
            result==Boolean.TRUE;
            result = parser.deliverMoreNodes(more))
        {
          System.out.println("\nSome parsing successful, trying more.\n");
            
          // Special test: Terminate parsing early.
          if(arg+1<args.length && "!".equals(args[arg+1]))
          {
            ++arg;
            more=false;
          }
            
        }
        
        if (result instanceof Boolean && ((Boolean)result)==Boolean.FALSE)
        {
          System.out.println("\nParser ended (EOF or on request).\n");
        }
        else if (result == null) {
          System.out.println("\nUNEXPECTED: Parser says shut down prematurely.\n");
        }
        else if (result instanceof Exception) {
          throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException((Exception)result);
          //          System.out.println("\nParser threw exception:");
          //          ((Exception)result).printStackTrace();
        }
        
      }

      catch(SAXException e)
      {
        e.printStackTrace();
      }
    }
    
  }

  
} // class IncrementalSAXSource_Xerces