cwspheaders.java

WAP Stack implementation jwap.sourceforge.net

/**
 * 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.wsp.pdu;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Date;
import java.util.Enumeration;
import java.util.Vector;

import net.sourceforge.jwap.util.Logger;
import net.sourceforge.jwap.util.Utils;
import net.sourceforge.jwap.wsp.WSPDecoder;
import net.sourceforge.jwap.wsp.header.CodePage;
import net.sourceforge.jwap.wsp.header.Header;
import net.sourceforge.jwap.wsp.header.HeaderParseException;
import net.sourceforge.jwap.wsp.header.WAPCodePage;



/**
 * This class represents WSP Headers
 *
 * @author Michel Marti
 */
public class CWSPHeaders 
{
    private static Logger logger = Logger.getLogger(CWSPHeaders.class);

    // List of Headers
    private Vector headers = new Vector();

    // Default codepage (WAP)
    private CodePage codePage;

    /**
     * Construct WSP Headers using the default WAP codepage
     */
    public CWSPHeaders() {
        this(WAPCodePage.getInstance());
    }

    /**
     * Construct WSP Headers using a specific codepage
     */
    public CWSPHeaders(CodePage codePage) {
        this.codePage = codePage;
    }

    
    /**
     * Construct WSP Headers by decoding a byte array
     * @param decoder the WSPDecoder for decoding
     * @param count the length of the headers within the data 
     * @param codePage the codepage for decoding the headers
     * @throws HeaderParseException if decoding fails
     */
    public CWSPHeaders(WSPDecoder decoder, int length, CodePage codePage)
        throws HeaderParseException
    {
        this(decoder,length, null, codePage);
    } 
    
    /**
     * Construct WSP Headers by decoding a byte array.
     * @param decoder the WSPDecoder for decoding
     * @param count the length of the headers within the data
     * @param stopOn the header after which decoding stops (may be null) 
     * @param codePage the codepage for decoding the headers
     * @throws HeaderParseException if decoding fails
     */
    public CWSPHeaders(WSPDecoder decoder, int length, String stopOn, CodePage codePage)
        throws HeaderParseException
    { 
        this(codePage);
        if( decoder == null ) {
            return;
        }
        
        if(decoder.getRemainingOctets() < length ) {
            logger.warn(length+": Length exceeds remaining octets in decoder");
            length = decoder.getRemainingOctets();   
        }

        if(logger.isDebugEnabled()) {
            int pos = decoder.seek(0);
            byte[] bytes = decoder.getBytes(length);
            decoder.pos(pos);
            logger.debug("\n"+Utils.hexDump("data to decode: ", bytes));    
        }
        
        if(stopOn!=null) {
            stopOn=stopOn.toLowerCase();
        }
                
        try {
            Header header;
            int offset = decoder.seek(0);
            
            while(decoder.seek(0) < (offset+length) ) {
                
                int start = decoder.seek(0);
                int octet = decoder.getUint8();
                int hlen = 0;
				// logger.debug("1st octet: "+Integer.toHexString(octet));
                
                if (octet == 127) { // Shift-Delimiter
                    // shift-delimiter + page identity
                    int pageIdentity = decoder.getUint8();
                    if( logger.isDebugEnabled()) {
                        logger.debug("Shift-delimiter detected, page identity: "+ pageIdentity);
                    }

                    if (pageIdentity != 1) {
                        throw new HeaderParseException(
                            "Code page switching not supported. (page identity: " +
                            pageIdentity + ")");
                    }
                    // ignore code page switching to default code page
                } else if( octet > 0 && octet <= 31 ) { // Short-cut-shift-delimiter
                    int shortCut = octet;
                    if(logger.isDebugEnabled()) {
                        logger.debug("Short-cut-shift-delimiter detected, page identity: "+shortCut);
                    }

                    if (shortCut != 1) {
                        throw new HeaderParseException(
                            "Code page switching not supported. (short-cut-shift-delimiter: " +
                            shortCut + ")");
                    }
                    // ignore code page switching to default code page
                    
                } else {
                    // message header
                    if ((octet & 0x80) == 0x80) { // short-integer
                        logger.debug("Well-Known-header detected");
                        // well-known-field-name + wap-value
                        int wellKnownHeader = octet & 0x7F;
                        
                        // header value
                        hlen = getHeaderValueSize(decoder);
                        hlen++; // We want the first octet as-well
                        
                    } // well-known-field-name + wap-value
                    else {
                        logger.debug("Application-header detected");
                        decoder.seek(-1);
                        // application header -> header name as string and value as string
                        // header name
                        hlen = getHeaderValueSize(decoder);
                        decoder.seek(hlen);

                        // value
                        hlen+= getHeaderValueSize(decoder);
                    }
                    decoder.pos(start);
                    byte[] encodedHeader = decoder.getBytes(hlen);
                    if(logger.isDebugEnabled()) {
                        logger.debug("\n"+Utils.hexDump("encoded header: ", encodedHeader));
                    }

                    try {
                        header = codePage.decode(encodedHeader);

                        if (header != null) {
                            if (logger.isDebugEnabled()) {
                                logger.debug("Decoded header: " + header);
                            }
                            headers.addElement(header);
                            if( stopOn != null && header.getName().toLowerCase().equals(stopOn) ) {
                                if(logger.isDebugEnabled()) {
                                    logger.debug(stopOn+": stop-on header reached, decode done");
                                }
                                break;
                            }
                        } else {
                            logger.warn(
                                "CodePage.decode() returned a null header: \n" +
                                Utils.hexDump(encodedHeader));
                        }
                    } catch (Exception unknown) {
                        // Since header parsing is not yet complete, warn and go-ahead
                        logger.warn("Exception while decoding header", unknown);

                        if (logger.isDebugEnabled()) {
                            logger.debug(Utils.hexDump(encodedHeader));
                        }
                    }
                }
                 // message header
            }
        } catch (IndexOutOfBoundsException e) {
            // ignore and return
        }
    }


    /**
     * Sets a WSP header with the given name and value. If the header had
     * already been set, the new value overwrites the previous one. The containsHeader
     * method can be used to test for the presence of a header before setting its value.
     */
    public void setHeader(String name, String value) {
        if (name == null) {
            return;
        }

        removeHeader(name);

        if (value != null) {
            headers.addElement(new Header(name, value));
        }
    }

    public void addHeader(String name, String value) {
        if ((name == null) || (value == null)) {
            return;
        }

        headers.addElement(new Header(name, value));
    }

    /**
     * Sets a WSP header with the given name and integer value. If the header
     * had already been set, the new value overwrites the previous one. The
     * containsHeader  method can be used to test for the presence of a header