ExtensionParser.java

/*
 *   
 *
 * Copyright  1990-2009 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation.
 * 
 * This program 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
 * General Public License version 2 for more details (a copy is
 * included at /legal/license.txt).
 * 
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 * 
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 */

package gov.nist.siplite.parser;

import gov.nist.core.*;
import gov.nist.siplite.header.*;

/**
 * Parser for content type header.
 *
 */
public class ExtensionParser extends ParametersParser {
    /** Default constructor. */
    protected ExtensionParser() {}

    /**
     * Constructor with header value.
     * @param value full header value respresented as a string
     */
    public ExtensionParser(String value) {
        super(value);
    }

    /**
     * Constructor with initial lexer engine.
     * @param lexer initial lexer engine
     */
    protected ExtensionParser(Lexer lexer) {
        super(lexer);
    }

    /**
     * Invokes parser for extension header field.
     * IMPL_NOTE: optimize it (maybe use ParserCore.nameValue()?).
     * @return the parsed extension header
     * @throws ParseException if a parsing error occurs
     */
    public Header parse() throws ParseException {
        String name = lexer.getNextToken(':');
        
        HeaderList hdrList = new HeaderList(name);
        
        lexer.consume(1);
        lexer.SPorHT();
        
        while (true) {
            String body = "";
            String rest = lexer.getRest();
            if (rest != null) {
                body = StringTokenizer.convertNewLines(rest.trim());
            }
        
            ExtensionHeader header;

            int index = getDelimiterIndex(body, ';');
            int separator = getDelimiterIndex(body, ',');
            if ((index != -1) || (separator != -1)) {
                if (((index != -1) && (index < separator)) || 
                        (separator == -1)) {
                    separator = index;
                }
                int currPos = lexer.getPtr();
                body = StringTokenizer.convertNewLines(
                        lexer.getBuffer().substring(currPos, currPos + 
                        separator).trim());
                lexer.consume(separator);
            } 
              
            header = new ExtensionHeader(name, body);
            super.parse(header);              
            hdrList.add(header);
            
            if (separator != -1) {
                this.lexer.SPorHT();
                if (lexer.lookAhead(0) == ',') {
                    this.lexer.match(',');
                    this.lexer.SPorHT();
                } else if (lexer.lookAhead(0) == '\n') {
                    break;
                } else {
                    throw createParseException("unexpected char");
                }            
            } else {
                break;
            }
        }
            
        return hdrList;   
    }
}