xmlcontenthandler.java

jwap 协议 udp 可以用于手机通讯

/**
 * JWAP - A Java Implementation of the WAP Protocols
 * Copyright (C) 2001-2004 Niko Bender
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

package net.sourceforge.jwap.util.wbxml;

import java.io.IOException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Stack;
import java.util.Vector;

import net.sourceforge.jwap.util.TransTable;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.DefaultHandler;


/**
 * <p>This class is used by WBXMLEncoder to encode an XML file into WBXML.
 * It catches the SAX events as the XML document is parsed. Token stream
 * is generated by reading the mapped byte codes for the elements and attributes
 * These mappings are read from the token repository for the given XML vocabulary</p>
 *
 * @author <a href="mailto:[e-mail]">Suvarna Kadam</a>
 * @see net.sourceforge.jwap.util.wbxml.WBXMLEncoder
 * @see net.sourceforge.jwap.util.wbxml.TokenRepository
 */

public class XMLContentHandler extends DefaultHandler implements LexicalHandler {
	private Stack parentTrace;
	private Vector tokens;
	private String encoding;
	private byte parentBitMask = (byte) 0x40;     // The bit representation 10000000
	private byte attributeBitMask = (byte) 0x80;  // The bit representation 01000000
	private byte[] stringTable;
	private int stringTableOffset = 0;
	private TokenRepository tokenRepository;
	private boolean switchCodepage;
	private boolean publicIdTokenAdded = false;
	/**
	 * Constructor for XMLContentHandler.
	 */
	public XMLContentHandler(String encoding) {
		this.encoding = encoding.toUpperCase();
		parentTrace = new Stack();
		tokens = new Vector();
	}

	/**
	 * @see org.xml.sax.ContentHandler#characters(char[], int, int)
	 */
	public void characters(char[] ch, int start, int length) throws SAXException {
	//	System.out.println("characters");
		String inlineString = String.valueOf(ch, start, length).trim();
		if (inlineString.length() > 0) {
			checkForParentTag();
			writeInlineString(inlineString);
		}
	}

	private int writeToStringBuf(String aString) {
		/*		int index = 0;
				for (int j = 0; j < aString.length(); j++)
					stringTable[]= (byte) aString.charAt(j);
				writeInlineStringToken((byte) 00);
		*/
		return 0;

	}

	/**
	 * @see org.xml.sax.ContentHandler#endDocument()
	 */
	public void endDocument() throws SAXException {
//		System.out.println("endDocument... tokens ----");
//		for (int i = 0; i < tokens.size(); i++) {
//			Token token = (Token) tokens.elementAt(i);
//			if (token.getName().equals("STR_INLINE"))
//				System.out.println((char) token.getValue() + "  "+token.getValue());
//			else
//				System.out.println(Integer.toHexString(token.getValue()) + " " + token.getName() + token.getValue());
//		}
		/*for (int i = 0; i < tokens.size(); i++) {
			Token token = (Token) tokens.elementAt(i);
			System.out.print(Integer.toHexString(token.getValue()) + " ");
		}*/
	}

	/**
	 * @see org.xml.sax.ContentHandler#endElement(String, String, String)
	 */
	public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
	//	System.out.println("endElement");
		// pop the element from the stack if any
		if (!parentTrace.isEmpty())
			parentTrace.pop();
		else
			tokens.addElement(new TagToken("END element" + localName, GlobalTokens.END));

	}

	/**
	 * @see org.xml.sax.ContentHandler#endPrefixMapping(String)
	 */
	public void endPrefixMapping(String prefix) throws SAXException {
	//	System.out.println("endPrefixMapping");
		if(switchCodepage) {
					TokenRepository.switchCodepage(null);
					switchCodepage = false;
			}
	}

	/**
	 * @see org.xml.sax.ErrorHandler#error(SAXParseException)
	 */
	public void error(SAXParseException exception) throws SAXException {
		//System.out.println("error");
	}

	/**
	 * @see org.xml.sax.ErrorHandler#fatalError(SAXParseException)
	 */
	public void fatalError(SAXParseException exception) throws SAXException {
		//System.out.println("fatal error");
	}

	/**
	 * @see org.xml.sax.ContentHandler#ignorableWhitespace(char[], int, int)
	 */
	public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
		//System.out.println("ignorableWhitespace");
	}

	/**
	 * @see org.xml.sax.DTDHandler#notationDecl(String, String, String)
	 */
	public void notationDecl(String name, String publicId, String systemId) throws SAXException {
		//System.out.println("notationDecl");
	}

	/**
	 * @see org.xml.sax.ContentHandler#processingInstruction(String, String)
	 */
	public void processingInstruction(String target, String data) throws SAXException {
		//System.out.println("target= " + target + " data " + data);
	}

	/**
	 * @throws SAXException
	 * @throws IOException
	 * @see org.xml.sax.EntityResolver#resolveEntity(String, String)
	 */
	public InputSource resolveEntity(String publicId, String systemId) throws IOException, SAXException {
	//	System.out.println("resolveEntity" + publicId + systemId);
	//	return new InputSource(systemId);
		 return super.resolveEntity(publicId,systemId);
	}

	/**
	 * @see org.xml.sax.ContentHandler#setDocumentLocator(Locator)
	 */
	public void setDocumentLocator(Locator locator) {
		//System.out.println("setDocumentLocator" + locator.getPublicId() + locator.getSystemId());
		super.setDocumentLocator(locator);
	}

	/**
	 * @see org.xml.sax.ContentHandler#skippedEntity(String)
	 */
	public void skippedEntity(String name) throws SAXException {
	//	System.out.println("skippedEntity");
		super.skippedEntity(name);
	}

	/**
	 * @see org.xml.sax.ContentHandler#startDocument()
	 * as per bnf of wbxml...
	 * ?? from where should the value for wbxml is taken??? application property??
	 */
	public void startDocument() throws SAXException {
		//System.out.println("startDocument");
		Token version = new Token("version",(byte)3);  // temporarily hardcoded to wbxml version 1.3
		// TODO read wbxml version from externally either from propeerties file or from command line arguments
		tokens.addElement(version);
	}

	/**
	 * @see org.xml.sax.ContentHandler#startElement(String, String, String, Attributes)
	 */
	public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException {
	//	System.out.println("startElement" + qName);
		if (!publicIdTokenAdded) {// The document does not have Doctype Declaration which means Public ID 1 (for "UNKNOWN") should be addded
			Token publicIdToken = new Token("publicid",(byte)1);
			tokens.addElement(publicIdToken);
			tokenRepository = TokenRepository.getInstance("1");
			publicIdTokenAdded = true;
		}
		checkForParentTag();
		boolean hasAttributes = atts.getLength() > 0;
		createTagToken(localName, hasAttributes);
		if (hasAttributes)
			createAttributeTags(localName, atts);
	}

	private void checkForParentTag() {
		// check if this element has a parent..
		if (!parentTrace.isEmpty()) {
			TagToken parentToken = (TagToken) parentTrace.pop();
			if (parentToken != null) { // apply the bit mask for parent tag.
				byte tokenValue = (byte) (parentToken.getValue() | parentBitMask);
				parentToken.setValue(tokenValue);
			}