/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.
*/
/*
* $Id: IncrementalSAXSource_Xerces.java,v 1.2.4.1 2005/09/15 08:15:08 suresh_emailid Exp $
*/
package com.sun.org.apache.xml.internal.dtm.ref;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import com.sun.org.apache.xerces.internal.parsers.SAXParser;
import com.sun.org.apache.xml.internal.res.XMLErrorResources;
import com.sun.org.apache.xml.internal.res.XMLMessages;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
/** <p>IncrementalSAXSource_Xerces takes advantage of the fact that Xerces1
* incremental mode is already a coroutine of sorts, and just wraps our
* IncrementalSAXSource API around it.</p>
*
* <p>Usage example: See main().</p>
*
* <p>Status: Passes simple main() unit-test. NEEDS JAVADOC.</p>
* */
public class IncrementalSAXSource_Xerces
implements IncrementalSAXSource
{
//
// Reflection. To allow this to compile with both Xerces1 and Xerces2, which
// require very different methods and objects, we need to avoid static
// references to those APIs. So until Xerces2 is pervasive and we're willing
// to make it a prerequisite, we will rely upon relection.
//
Method fParseSomeSetup=null; // Xerces1 method
Method fParseSome=null; // Xerces1 method
Object fPullParserConfig=null; // Xerces2 pull control object
Method fConfigSetInput=null; // Xerces2 method
Method fConfigParse=null; // Xerces2 method
Method fSetInputSource=null; // Xerces2 pull control method
Constructor fConfigInputSourceCtor=null; // Xerces2 initialization method
Method fConfigSetByteStream=null; // Xerces2 initialization method
Method fConfigSetCharStream=null; // Xerces2 initialization method
Method fConfigSetEncoding=null; // Xerces2 initialization method
Method fReset=null; // Both Xerces1 and Xerces2, but diff. signatures
//
// Data
//
SAXParser fIncrementalParser;
private boolean fParseInProgress=false;
//
// Constructors
//
/** Create a IncrementalSAXSource_Xerces, and create a SAXParser
* to go with it. Xerces2 incremental parsing is only supported if
* this constructor is used, due to limitations in the Xerces2 API (as of
* Beta 3). If you don't like that restriction, tell the Xerces folks that
* there should be a simpler way to request incremental SAX parsing.
* */
public IncrementalSAXSource_Xerces()
throws NoSuchMethodException
{
try
{
// Xerces-2 incremental parsing support (as of Beta 3)
// ContentHandlers still get set on fIncrementalParser (to get
// conversion from XNI events to SAX events), but
// _control_ for incremental parsing must be exercised via the config.
//
// At this time there's no way to read the existing config, only
// to assert a new one... and only when creating a brand-new parser.
//
// Reflection is used to allow us to continue to compile against
// Xerces1. If/when we can abandon the older versions of the parser,
// this will simplify significantly.
// If we can't get the magic constructor, no need to look further.
Class xniConfigClass=ObjectFactory.findProviderClass(
"com.sun.org.apache.xerces.internal.xni.parser.XMLParserConfiguration",
ObjectFactory.findClassLoader(), true);
Class[] args1={xniConfigClass};
Constructor ctor=SAXParser.class.getConstructor(args1);
// Build the parser configuration object. StandardParserConfiguration
// happens to implement XMLPullParserConfiguration, which is the API
// we're going to want to use.
Class xniStdConfigClass=ObjectFactory.findProviderClass(
"com.sun.org.apache.xerces.internal.parsers.StandardParserConfiguration",
ObjectFactory.findClassLoader(), true);
fPullParserConfig=xniStdConfigClass.newInstance();
Object[] args2={fPullParserConfig};
fIncrementalParser = (SAXParser)ctor.newInstance(args2);
// Preload all the needed the configuration methods... I want to know they're
// all here before we commit to trying to use them, just in case the
// API changes again.
Class fXniInputSourceClass=ObjectFactory.findProviderClass(
"com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource",
ObjectFactory.findClassLoader(), true);
Class[] args3={fXniInputSourceClass};
fConfigSetInput=xniStdConfigClass.getMethod("setInputSource",args3);
Class[] args4={String.class,String.class,String.class};
fConfigInputSourceCtor=fXniInputSourceClass.getConstructor(args4);
Class[] args5={java.io.InputStream.class};
fConfigSetByteStream=fXniInputSourceClass.getMethod("setByteStream",args5);
Class[] args6={java.io.Reader.class};
fConfigSetCharStream=fXniInputSourceClass.getMethod("setCharacterStream",args6);
Class[] args7={String.class};
fConfigSetEncoding=fXniInputSourceClass.getMethod("setEncoding",args7);
Class[] argsb={Boolean.TYPE};
fConfigParse=xniStdConfigClass.getMethod("parse",argsb);
Class[] noargs=new Class[0];
fReset=fIncrementalParser.getClass().getMethod("reset",noargs);
}
catch(Exception e)
{
// Fallback if this fails (implemented in createIncrementalSAXSource) is
// to attempt Xerces-1 incremental setup. Can't do tail-call in
// constructor, so create new, copy Xerces-1 initialization,
// then throw it away... Ugh.
IncrementalSAXSource_Xerces dummy=new IncrementalSAXSource_Xerces(new SAXParser());
this.fParseSomeSetup=dummy.fParseSomeSetup;
this.fParseSome=dummy.fParseSome;
this.fIncrementalParser=dummy.fIncrementalParser;
}
}
/** Create a IncrementalSAXSource_Xerces wrapped around
* an existing SAXParser. Currently this works only for recent
* releases of Xerces-1. Xerces-2 incremental is currently possible
* only if we are allowed to create the parser instance, due to
* limitations in the API exposed by Xerces-2 Beta 3; see the
* no-args constructor for that code.
*
* @exception if the SAXParser class doesn't support the Xerces
* incremental parse operations. In that case, caller should
* fall back upon the IncrementalSAXSource_Filter approach.
* */
public IncrementalSAXSource_Xerces(SAXParser parser)
throws NoSuchMethodException
{
// Reflection is used to allow us to compile against
// Xerces2. If/when we can abandon the older versions of the parser,
// this constructor will simply have to fail until/unless the
// Xerces2 incremental support is made available on previously
// constructed SAXParser instances.
fIncrementalParser=parser;
Class me=parser.getClass();
Class[] parms={InputSource.class};
fParseSomeSetup=me.getMethod("parseSomeSetup",parms);
parms=new Class[0];
fParseSome=me.getMethod("parseSome",parms);
// Fallback if this fails (implemented in createIncrementalSAXSource) is
// to use IncrementalSAXSource_Filter rather than Xerces-specific code.
}
//
// Factories
//
static public IncrementalSAXSource createIncrementalSAXSource()
{
try
{
return new IncrementalSAXSource_Xerces();
}
catch(NoSuchMethodException e)
{
// Xerces version mismatch; neither Xerces1 nor Xerces2 succeeded.
// Fall back on filtering solution.
IncrementalSAXSource_Filter iss=new IncrementalSAXSource_Filter();
iss.setXMLReader(new SAXParser());
return iss;
}
}
static public IncrementalSAXSource
createIncrementalSAXSource(SAXParser parser) {
try
{
return new IncrementalSAXSource_Xerces(parser);
}
catch(NoSuchMethodException e)
{
// Xerces version mismatch; neither Xerces1 nor Xerces2 succeeded.
// Fall back on filtering solution.
IncrementalSAXSource_Filter iss=new IncrementalSAXSource_Filter();
iss.setXMLReader(parser);
return iss;
}
}
//
// Public methods
//
// Register handler directly with the incremental parser
public void setContentHandler(org.xml.sax.ContentHandler handler)
{
// Typecast required in Xerces2; SAXParser doesn't inheret XMLReader
// %OPT% Cast at asignment?
((XMLReader)fIncrementalParser).setContentHandler(handler);
}
// Register handler directly with the incremental parser
public void setLexicalHandler(org.xml.sax.ext.LexicalHandler handler)
{
// 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
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