Java tutorial
/* * Copyright 1999-2005 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. */ package org.apache.cocoon.template.script; import java.util.Stack; import org.apache.cocoon.template.JXTemplateGenerator; import org.apache.cocoon.template.environment.ParsingContext; import org.apache.cocoon.template.instruction.Instruction; import org.apache.cocoon.template.script.event.*; import org.apache.commons.lang.StringUtils; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.ext.LexicalHandler; import org.xml.sax.helpers.AttributesImpl; import org.xml.sax.helpers.LocatorImpl; /** * @version SVN $Id: Parser.java 325973 2005-10-17 19:59:39Z lgawron $ */ public class Parser implements ContentHandler, LexicalHandler { StartDocument startEvent; Event lastEvent; Stack stack = new Stack(); Locator locator; Locator charLocation; StringBuffer charBuf; public static final Locator NULL_LOCATOR = new LocatorImpl(); protected ParsingContext parsingContext; public Parser() { } public Parser(ParsingContext parsingContext) { this.parsingContext = parsingContext; } public void setParsingContext(ParsingContext parsingContext) { this.parsingContext = parsingContext; } public StartDocument getStartEvent() { return this.startEvent; } protected void recycle() { startEvent = null; lastEvent = null; stack.clear(); locator = null; charLocation = null; charBuf = null; } private void addEvent(Event ev) throws SAXException { if (ev != null) { if (lastEvent == null) { lastEvent = startEvent = new StartDocument(locator); } else { flushChars(); } lastEvent.setNext(ev); lastEvent = ev; } else { throw new NullPointerException("null event"); } } void flushChars() throws SAXException { if (charBuf != null) { char[] chars = new char[charBuf.length()]; charBuf.getChars(0, charBuf.length(), chars, 0); Characters ev = new Characters(this.parsingContext, charLocation, chars, 0, chars.length); lastEvent.setNext(ev); lastEvent = ev; charLocation = null; charBuf = null; } } public void characters(char[] ch, int start, int length) throws SAXException { if (charBuf == null) { charBuf = new StringBuffer(length); charLocation = locator != null ? new LocatorImpl(locator) : NULL_LOCATOR; } charBuf.append(ch, start, length); } public void endDocument() throws SAXException { StartDocument startDoc = (StartDocument) stack.pop(); EndDocument endDoc = new EndDocument(locator); startDoc.setEndDocument(endDoc); addEvent(endDoc); } public void endElement(String namespaceURI, String localName, String raw) throws SAXException { Event start = (Event) stack.pop(); Event newEvent = null; if (start instanceof Instruction) { Instruction startInstruction = (Instruction) start; EndInstruction endInstruction = new EndInstruction(locator, startInstruction); newEvent = endInstruction; addEvent(newEvent); startInstruction.endNotify(); } else { StartElement startElement = (StartElement) start; newEvent = new EndElement(locator, startElement); startElement.setEndElement((EndElement) newEvent); addEvent(newEvent); } } public void endPrefixMapping(String prefix) throws SAXException { EndPrefixMapping endPrefixMapping = new EndPrefixMapping(locator, prefix); addEvent(endPrefixMapping); } public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException { Event ev = new IgnorableWhitespace(this.parsingContext, locator, ch, start, length); addEvent(ev); } public void processingInstruction(String target, String data) throws SAXException { Event pi = new ProcessingInstruction(locator, target, data); addEvent(pi); } public void setDocumentLocator(Locator locator) { this.locator = locator; } public void skippedEntity(String name) throws SAXException { addEvent(new SkippedEntity(locator, name)); } public void startDocument() { startEvent = new StartDocument(locator); lastEvent = startEvent; stack.push(lastEvent); } public void startElement(String namespaceURI, String localName, String qname, Attributes attrs) throws SAXException { Event newEvent = null; AttributesImpl elementAttributes = new AttributesImpl(attrs); int attributeCount = elementAttributes.getLength(); for (int i = 0; i < attributeCount; i++) { String attributeURI = elementAttributes.getURI(i); if (StringUtils.equals(attributeURI, JXTemplateGenerator.NS)) { // TODO: template properties should be allowed only on template // root getStartEvent().getTemplateProperties().put(elementAttributes.getLocalName(i), this.parsingContext .getStringTemplateParser().compileExpr(elementAttributes.getValue(i), null, locator)); elementAttributes.removeAttribute(i--); } } StartElement startElement = new StartElement(this.parsingContext, locator, namespaceURI, localName, qname, elementAttributes); InstructionFactory instructionFactory = this.parsingContext.getInstructionFactory(); if (instructionFactory.isInstruction(startElement)) newEvent = instructionFactory.createInstruction(this.parsingContext, startElement, attrs, stack); else newEvent = startElement; stack.push(newEvent); addEvent(newEvent); } public void startPrefixMapping(String prefix, String uri) throws SAXException { addEvent(new StartPrefixMapping(locator, prefix, uri)); } public void comment(char ch[], int start, int length) throws SAXException { // DO NOTHING } public void endCDATA() throws SAXException { addEvent(new EndCDATA(locator)); } public void endDTD() throws SAXException { addEvent(new EndDTD(locator)); } public void endEntity(String name) throws SAXException { addEvent(new EndEntity(locator, name)); } public void startCDATA() throws SAXException { addEvent(new StartCDATA(locator)); } public void startDTD(String name, String publicId, String systemId) throws SAXException { addEvent(new StartDTD(locator, name, publicId, systemId)); } public void startEntity(String name) throws SAXException { addEvent(new StartEntity(locator, name)); } }