/** * 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. Class me = this.getClass(); // If we can't get the magic constructor, no need to look further. Class xniConfigClass = me.forName("org.apache.xerces.xni.parser.XMLParserConfiguration"); 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 = me.forName("org.apache.xerces.parsers.StandardParserConfiguration"); 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 = me.forName("org.apache.xerces.xni.parser.XMLInputSource"); 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. }