xmldocumentscannerimpl.java

java1.6众多例子参考

                //throw e;
            }
            
            // cleanup
            finally {
                fEntityManager.setEntityHandler(XMLDocumentScannerImpl.this);
            }
            
            return true;
            
        }
        
        // dispatch(boolean):boolean
        
    } // class DTDDriver
    
    /**
     * Driver to handle content scanning.
     *
     * @author Andy Clark, IBM
     * @author Eric Ye, IBM
     */
    protected class ContentDriver
            extends FragmentContentDriver {
        
        //
        // Protected methods
        //
        
        // hooks
        
        // NOTE: These hook methods are added so that the full document
        //       scanner can share the majority of code with this class.
        
        /**
         * Scan for DOCTYPE hook. This method is a hook for subclasses
         * to add code to handle scanning for a the "DOCTYPE" string
         * after the string "<!" has been scanned.
         *
         * @return True if the "DOCTYPE" was scanned; false if "DOCTYPE"
         *          was not scanned.
         */
        protected boolean scanForDoctypeHook()
        throws IOException, XNIException {
            
            if (fEntityScanner.skipString(DOCTYPE)) {
                setScannerState(SCANNER_STATE_DOCTYPE);
                //                fEntityScanner.markStartOfDTD();
                return true;
            }
            return false;
            
        } // scanForDoctypeHook():boolean
        
        /**
         * Element depth iz zero. This methos is a hook for subclasses
         * to add code to handle when the element depth hits zero. When
         * scanning a document fragment, an element depth of zero is
         * normal. However, when scanning a full XML document, the
         * scanner must handle the trailing miscellanous section of
         * the document after the end of the document's root element.
         *
         * @return True if the caller should stop and return true which
         *          allows the scanner to switch to a new scanning
         *          driver. A return value of false indicates that
         *          the content driver should continue as normal.
         */
        protected boolean elementDepthIsZeroHook()
        throws IOException, XNIException {
            
            setScannerState(SCANNER_STATE_TRAILING_MISC);
            setDriver(fTrailingMiscDriver);
            return true;
            
        } // elementDepthIsZeroHook():boolean
        
        /**
         * Scan for root element hook. This method is a hook for
         * subclasses to add code that handles scanning for the root
         * element. When scanning a document fragment, there is no
         * "root" element. However, when scanning a full XML document,
         * the scanner must handle the root element specially.
         *
         * @return True if the caller should stop and return true which
         *          allows the scanner to switch to a new scanning
         *          driver. A return value of false indicates that
         *          the content driver should continue as normal.
         */
        protected boolean scanRootElementHook()
        throws IOException, XNIException {
            
            if (scanStartElement()) {
                setScannerState(SCANNER_STATE_TRAILING_MISC);
                setDriver(fTrailingMiscDriver);
                return true;
            }
            return false;
            
        } // scanRootElementHook():boolean
        
        /**
         * End of file hook. This method is a hook for subclasses to
         * add code that handles the end of file. The end of file in
         * a document fragment is OK if the markup depth is zero.
         * However, when scanning a full XML document, an end of file
         * is always premature.
         */
        protected void endOfFileHook(EOFException e)
        throws IOException, XNIException {
            
            reportFatalError("PrematureEOF", null);
            // in case continue-after-fatal-error set, should not do this...
            //throw e;
            
        } // endOfFileHook()
        
        protected void resolveExternalSubsetAndRead()
        throws IOException, XNIException {
            
            fDTDDescription.setValues(null, null, fEntityManager.getCurrentResourceIdentifier().getExpandedSystemId(), null);
            fDTDDescription.setRootName(fElementQName.rawname);            
            XMLInputSource src = fExternalSubsetResolver.getExternalSubset(fDTDDescription);
            
            if (src != null) {
                fDoctypeName = fElementQName.rawname;
                fDoctypePublicId = src.getPublicId();
                fDoctypeSystemId = src.getSystemId();
                // call document handler
                if (fDocumentHandler != null) {
                    // This inserts a doctypeDecl event into the stream though no
                    // DOCTYPE existed in the instance document.
                    fDocumentHandler.doctypeDecl(fDoctypeName, fDoctypePublicId, fDoctypeSystemId, null);
                }
                try {
                    fDTDScanner.setInputSource(src);
                    while (fDTDScanner.scanDTDExternalSubset(true));
                } finally {
                    fEntityManager.setEntityHandler(XMLDocumentScannerImpl.this);
                }
            }
        } // resolveExternalSubsetAndRead()
        
        
        
    } // class ContentDriver
    
    /**
     * Driver to handle trailing miscellaneous section scanning.
     *
     * @author Andy Clark, IBM
     * @author Eric Ye, IBM
     */
    protected final class TrailingMiscDriver
            implements Driver {
        
        //
        // Driver methods
        //
        public int next() throws IOException, XNIException{
            //this could for cases like <foo/>
            //look at scanRootElementHook
            if(fEmptyElement){
                fEmptyElement = false;
                return XMLEvent.END_ELEMENT;
            }
            
            try {
                if(fScannerState == SCANNER_STATE_TERMINATED){
                    return XMLEvent.END_DOCUMENT ;}
                do {
                    switch (fScannerState) {
                        case SCANNER_STATE_TRAILING_MISC: {
                            
                            fEntityScanner.skipSpaces();
                            //we should have reached the end of the document in
                            //most cases.
                            if(fScannerState == SCANNER_STATE_TERMINATED ){
                                return XMLEvent.END_DOCUMENT ;
                            }
                            if (fEntityScanner.skipChar('<')) {
                                setScannerState(SCANNER_STATE_START_OF_MARKUP);
                            } else {
                                setScannerState(SCANNER_STATE_CONTENT);
                            }
                            break;
                        }
                        case SCANNER_STATE_START_OF_MARKUP: {
                            fMarkupDepth++;
                            if (fEntityScanner.skipChar('?')) {
                                setScannerState(SCANNER_STATE_PI);
                            } else if (fEntityScanner.skipChar('!')) {
                                setScannerState(SCANNER_STATE_COMMENT);
                            } else if (fEntityScanner.skipChar('/')) {
                                reportFatalError("MarkupNotRecognizedInMisc",
                                        null);
                            } else if (XMLChar.isNameStart(fEntityScanner.peekChar())) {
                                reportFatalError("MarkupNotRecognizedInMisc",
                                        null);
                                scanStartElement();
                                setScannerState(SCANNER_STATE_CONTENT);
                            } else {
                                reportFatalError("MarkupNotRecognizedInMisc",
                                        null);
                            }
                            break;
                        }
                    }
                }while(fScannerState == SCANNER_STATE_START_OF_MARKUP || fScannerState == SCANNER_STATE_TRAILING_MISC);
                if(DEBUG_NEXT){
                    System.out.println("State set by deciding while loop [TrailingMiscellaneous] is = " + getScannerStateName(fScannerState));
                }
                switch (fScannerState){
                    case SCANNER_STATE_PI: {
                        fContentBuffer.clear();
                        scanPI(fContentBuffer);
                        setScannerState(SCANNER_STATE_TRAILING_MISC);
                        return XMLEvent.PROCESSING_INSTRUCTION ;
                    }
                    case SCANNER_STATE_COMMENT: {
                        if (!fEntityScanner.skipString(COMMENTSTRING)) {
                            reportFatalError("InvalidCommentStart", null);
                        }
                        scanComment();
                        setScannerState(SCANNER_STATE_TRAILING_MISC);
                        return XMLEvent.COMMENT;
                    }
                    case SCANNER_STATE_CONTENT: {
                        int ch = fEntityScanner.peekChar();
                        if (ch == -1) {
                            setScannerState(SCANNER_STATE_TERMINATED);
                            return XMLEvent.END_DOCUMENT ;
                        } else{
                            reportFatalError("ContentIllegalInTrailingMisc",
                                    null);
                            fEntityScanner.scanChar();
                            setScannerState(SCANNER_STATE_TRAILING_MISC);
                            return XMLEvent.CHARACTERS;
                        }
                        
                    }
                    case SCANNER_STATE_REFERENCE: {
                        reportFatalError("ReferenceIllegalInTrailingMisc",
                                null);
                        setScannerState(SCANNER_STATE_TRAILING_MISC);
                        return XMLEvent.ENTITY_REFERENCE ;
                    }
                    case SCANNER_STATE_TERMINATED: {
                        //there can't be any element after SCANNER_STATE_TERMINATED or when the parser
                        //has reached the end of document
                        setScannerState(SCANNER_STATE_NO_SUCH_ELEMENT_EXCEPTION);
                        //xxx what to do when the scanner has reached the terminating state.
                        return XMLEvent.END_DOCUMENT ;
                    }
                    case SCANNER_STATE_NO_SUCH_ELEMENT_EXCEPTION:{
                        throw new java.util.NoSuchElementException("No more events to be parsed");
                    }
                    default: throw new XNIException("Scanner State " + fScannerState + " not Recognized ");
                }//switch
                
            } catch (EOFException e) {
                // NOTE: This is the only place we're allowed to reach
                //       the real end of the document stream. Unless the
                //       end of file was reached prematurely.
                if (fMarkupDepth != 0) {
                    reportFatalError("PrematureEOF", null);
                    return -1;
                    //throw e;
                }
                System.out.println("EOFException thrown") ;
                setScannerState(SCANNER_STATE_TERMINATED);
            }
            
            return XMLEvent.END_DOCUMENT;
            
        }//next
        
    } // class TrailingMiscDriver
    
    /**
     * Implements XMLBufferListener interface.
     */
    

    /**
     * receives callbacks from {@link XMLEntityReader } when buffer
     * is being changed.
     * @param refreshPosition
     */
    public void refresh(int refreshPosition){
        super.refresh(refreshPosition);
        if(fReadingDTD){
            Entity entity = fEntityScanner.getCurrentEntity();
            if(entity instanceof Entity.ScannedEntity){
                fEndPos=((Entity.ScannedEntity)entity).position;
            }
            fDTDDecl.append(((Entity.ScannedEntity)entity).ch,fStartPos , fEndPos-fStartPos);
            fStartPos = refreshPosition;
        }
    }
    
} // class XMLDocumentScannerImpl