content: /*
  * Conditions Of Use
  *
  * This software was developed by employees of the National Institute of
  * Standards and Technology (NIST), an agency of the Federal Government.
  * Pursuant to title 15 Untied States Code Section 105, works of NIST
  * employees are not subject to copyright protection in the United States
  * and are considered to be in the public domain.  As a result, a formal
  * license is not needed to use the software.
  *
  * This software is provided by NIST as a service and is expressly
  * provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
  * OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
  * AND DATA ACCURACY.  NIST does not warrant or make any representations
  * regarding the use of the software or the results thereof, including but
  * not limited to the correctness, accuracy, reliability or usefulness of
  * the software.
  *
  * Permission to use this software is contingent upon your acceptance
  * of the terms of this agreement
  *
  * .
  *
  */
  package gov2.nist.javax2.sip.parser;
  import gov2.nist.core.Debug;
  import gov2.nist.core.LexerCore;
  import gov2.nist.core.ParserCore;
  import gov2.nist.core.Token;
  
  import java.text.ParseException;
  
  /**
   * Base parser class.
   *
   * @version 1.2 $Revision: 1.10 $ $Date: 2009/07/17 18:58:01 $
   *
   * @author M. Ranganathan   <br/>
   *
   *
   */
  public abstract class Parser extends ParserCore implements TokenTypes {
  
      protected ParseException createParseException(String exceptionString) {
          return new ParseException(
              lexer.getBuffer() + ":" + exceptionString,
              lexer.getPtr());
      }
  
      protected Lexer getLexer() {
          return (Lexer) this.lexer;
      }
  
      protected String sipVersion() throws ParseException {
          if (debug)
              dbg_enter("sipVersion");
          try {
              Token tok = lexer.match(SIP);
              if (!tok.getTokenValue().equalsIgnoreCase("SIP"))
                  createParseException("Expecting SIP");
              lexer.match('/');
              tok = lexer.match(ID);
              if (!tok.getTokenValue().equals("2.0"))
                  createParseException("Expecting SIP/2.0");
  
              return "SIP/2.0";
          } finally {
              if (debug)
                  dbg_leave("sipVersion");
          }
      }
  
      /**
       * parses a method. Consumes if a valid method has been found.
       */
      protected String method() throws ParseException {
          try {
              if (debug)
                  dbg_enter("method");
              Token[] tokens = this.lexer.peekNextToken(1);
              Token token = (Token) tokens[0];
              if (token.getTokenType() == INVITE
                  || token.getTokenType() == ACK
                  || token.getTokenType() == OPTIONS
                  || token.getTokenType() == BYE
                  || token.getTokenType() == REGISTER
                  || token.getTokenType() == CANCEL
                  || token.getTokenType() == SUBSCRIBE
                  || token.getTokenType() == NOTIFY
                  || token.getTokenType() == PUBLISH
                  || token.getTokenType() == MESSAGE
                  || token.getTokenType() == ID) {
                  lexer.consume();
                  return token.getTokenValue();
              } else {
                  throw createParseException("Invalid Method");
              }
          } finally {
              if (Debug.debug)
                  dbg_leave("method");
          }
      }
  
      /**
       * Verifies that a given string matches the 'token' production in RFC3261
       *
       * @param token
       * @throws ParseException - if there are invalid characters
       *
       * @author JvB
       */
      public static final void checkToken( String token ) throws ParseException {
  
          if (token == null || token.length()==0 ) {
              throw new ParseException("null or empty token", -1 );
          } else {
              // JvB: check that it is a valid token
              for ( int i=0; i<token.length(); ++i ) {
                  if ( !LexerCore.isTokenChar( token.charAt(i) )) {
                      throw new ParseException( "Invalid character(s) in string (not allowed in 'token')", i );
                  }
              }
          }
      }
  }
  /*
   * $Log: Parser.java,v $
   * Revision 1.10  2009/07/17 18:58:01  emcho
   * Converts indentation tabs to spaces so that we have a uniform indentation policy in the whole project.
   *
   * Revision 1.9  2008/01/18 11:19:24  jbemmel
   * added a method to check strings for valid token characters
   *
   * Revision 1.8  2007/02/23 14:56:05  belangery
   * Added performance improvement around header name lowercase conversion.
   *
   * Revision 1.7  2006/09/27 15:02:43  mranga
   * Issue number:
   * Obtained from:
   * Submitted by:
   * Reviewed by:   mranga
   * rfc 2543 transaction matching. fix for MESSAGE request type parsing.
   * CVS: ----------------------------------------------------------------------
   * CVS: Issue number:
   * CVS:   If this change addresses one or more issues,
   * CVS:   then enter the issue number(s) here.
   * CVS: Obtained from:
   * CVS:   If this change has been taken from another system,
   * CVS:   then name the system in this line, otherwise delete it.
   * CVS: Submitted by:
   * CVS:   If this code has been contributed to the project by someone else; i.e.,
   * CVS:   they sent us a patch or a set of diffs, then include their name/email
   * CVS:   address here. If this is your work then delete this line.
   * CVS: Reviewed by:
   * CVS:   If we are doing pre-commit code reviews and someone else has
   * CVS:   reviewed your changes, include their name(s) here.
   * CVS:   If you have not had it reviewed then delete this line.
   *
   * Revision 1.6  2006/07/13 09:02:18  mranga
   * Issue number:
   * Obtained from:
   * Submitted by:  jeroen van bemmel
   * Reviewed by:   mranga
   * Moved some changes from jain-sip-1.2 to java.net
   *
   * CVS: ----------------------------------------------------------------------
   * CVS: Issue number:
   * CVS:   If this change addresses one or more issues,
   * CVS:   then enter the issue number(s) here.
   * CVS: Obtained from:
   * CVS:   If this change has been taken from another system,
   * CVS:   then name the system in this line, otherwise delete it.
   * CVS: Submitted by:
   * CVS:   If this code has been contributed to the project by someone else; i.e.,
   * CVS:   they sent us a patch or a set of diffs, then include their name/email
   * CVS:   address here. If this is your work then delete this line.
   * CVS: Reviewed by:
   * CVS:   If we are doing pre-commit code reviews and someone else has
   * CVS:   reviewed your changes, include their name(s) here.
   * CVS:   If you have not had it reviewed then delete this line.
   *
   * Revision 1.5  2006/06/19 06:47:27  mranga
   * javadoc fixups
   *
   * Revision 1.4  2006/06/16 15:26:28  mranga
   * Added NIST disclaimer to all public domain files. Clean up some javadoc. Fixed a leak
   *
   * Revision 1.3  2005/11/21 23:24:49  jeroen
   * "SIP" is case insensitive
   *
   * Revision 1.2  2005/10/27 20:49:00  jeroen
   * added support for RFC3903 PUBLISH
   *
   * Revision 1.1.1.1  2005/10/04 17:12:35  mranga
   *
   * Import
   *
   *
   * Revision 1.3  2004/01/22 13:26:31  sverker
   * Issue number:
   * Obtained from:
   * Submitted by:  sverker
   * Reviewed by:   mranga
   *
   * Major reformat of code to conform with style guide. Resolved compiler and javadoc warnings. Added CVS tags.
   *
   * CVS: ----------------------------------------------------------------------
   * CVS: Issue number:
   * CVS:   If this change addresses one or more issues,
   * CVS:   then enter the issue number(s) here.
   * CVS: Obtained from:
   * CVS:   If this change has been taken from another system,
   * CVS:   then name the system in this line, otherwise delete it.
   * CVS: Submitted by:
   * CVS:   If this code has been contributed to the project by someone else; i.e.,
   * CVS:   they sent us a patch or a set of diffs, then include their name/email
   * CVS:   address here. If this is your work then delete this line.
   * CVS: Reviewed by:
   * CVS:   If we are doing pre-commit code reviews and someone else has
   * CVS:   reviewed your changes, include their name(s) here.
   * CVS:   If you have not had it reviewed then delete this line.
   *
   */
  