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      1 /*
      2 * Conditions Of Use
      3 *
      4 * This software was developed by employees of the National Institute of
      5 * Standards and Technology (NIST), an agency of the Federal Government.
      6 * Pursuant to title 15 Untied States Code Section 105, works of NIST
      7 * employees are not subject to copyright protection in the United States
      8 * and are considered to be in the public domain.  As a result, a formal
      9 * license is not needed to use the software.
     10 *
     11 * This software is provided by NIST as a service and is expressly
     12 * provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
     13 * OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
     14 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
     15 * AND DATA ACCURACY.  NIST does not warrant or make any representations
     16 * regarding the use of the software or the results thereof, including but
     17 * not limited to the correctness, accuracy, reliability or usefulness of
     18 * the software.
     19 *
     20 * Permission to use this software is contingent upon your acceptance
     21 * of the terms of this agreement
     22 *
     23 * .
     24 *
     25 */
     26 package gov.nist.javax.sip.parser;
     27 
     28 import gov.nist.core.Token;
     29 import gov.nist.javax.sip.header.*;
     30 import java.text.ParseException;
     31 
     32 /**
     33  * Parser for UserAgent header.
     34  *
     35  * @version 1.2 $Revision: 1.15 $ $Date: 2009/07/17 18:58:07 $
     36  *
     37  * @author Olivier Deruelle  <br/>
     38  * @author M. Ranganathan  <br/>
     39  *
     40  *
     41  */
     42 public class UserAgentParser extends HeaderParser {
     43 
     44     /**
     45      * Constructor
     46      *
     47      * @param userAgent -
     48      *            UserAgent header to parse
     49      */
     50     public UserAgentParser(String userAgent) {
     51         super(userAgent);
     52     }
     53 
     54     /**
     55      * Constructor
     56      *
     57      * @param lexer -
     58      *            the lexer to use.
     59      */
     60     protected UserAgentParser(Lexer lexer) {
     61         super(lexer);
     62     }
     63 
     64     /**
     65      * parse the message. Note that we have losened up on the parsing quite a bit because
     66      * user agents tend to be very bad about specifying the user agent according to RFC.
     67      *
     68      * @return SIPHeader (UserAgent object)
     69      * @throws SIPParseException
     70      *             if the message does not respect the spec.
     71      */
     72     public SIPHeader parse() throws ParseException {
     73         if (debug)
     74             dbg_enter("UserAgentParser.parse");
     75         UserAgent userAgent = new UserAgent();
     76         try {
     77             headerName(TokenTypes.USER_AGENT);
     78             if (this.lexer.lookAhead(0) == '\n')
     79                 throw createParseException("empty header");
     80 
     81             /*
     82              * BNF User-Agent = "User-Agent" HCOLON server-val *(LWS server-val)
     83              * server-val = product / comment product = token [SLASH
     84              * product-version] product-version = token
     85              */
     86             while (this.lexer.lookAhead(0) != '\n'
     87                     && this.lexer.lookAhead(0) != '\0') {
     88 
     89                 if (this.lexer.lookAhead(0) == '(') {
     90                     String comment = this.lexer.comment();
     91                     userAgent.addProductToken('(' + comment + ')');
     92                 } else {
     93                     // product = token [SLASHproduct-version]
     94                     // product-version = token
     95                     // The RFC Does NOT allow this space but we are generous in what we accept
     96 
     97                     this.getLexer().SPorHT();
     98 
     99 
    100                     String product = this.lexer.byteStringNoSlash();
    101                     if ( product == null ) throw createParseException("Expected product string");
    102 
    103                     StringBuffer productSb = new StringBuffer(product);
    104                     // do we possibily have the optional product-version?
    105                     if (this.lexer.peekNextToken().getTokenType() == TokenTypes.SLASH) {
    106                         // yes
    107                         this.lexer.match(TokenTypes.SLASH);
    108                         // product-version
    109                         // The RFC Does NOT allow this space but we are generous in what we accept
    110                         this.getLexer().SPorHT();
    111 
    112                         String productVersion = this.lexer.byteStringNoSlash();
    113 
    114                         if ( productVersion == null ) throw createParseException("Expected product version");
    115 
    116                         productSb.append("/");
    117 
    118                         productSb.append(productVersion);
    119                     }
    120 
    121                     userAgent.addProductToken(productSb.toString());
    122                 }
    123                 // LWS
    124                 this.lexer.SPorHT();
    125             }
    126         } finally {
    127             if (debug)
    128                 dbg_leave("UserAgentParser.parse");
    129         }
    130 
    131         return userAgent;
    132     }
    133 
    134 
    135       public static void main(String args[]) throws ParseException { String
    136       userAgent[] = { "User-Agent: Softphone/Beta1.5 \n", "User-Agent:Nist/Beta1 (beta version) \n", "User-Agent: Nist UA (beta version)\n",
    137       "User-Agent: Nist1.0/Beta2 Ubi/vers.1.0 (very cool) \n" ,
    138       "User-Agent: SJphone/1.60.299a/L (SJ Labs)\n",
    139       "User-Agent: sipXecs/3.5.11 sipXecs/sipxbridge (Linux)\n"};
    140 
    141       for (int i = 0; i < userAgent.length; i++ ) { UserAgentParser parser =
    142       new UserAgentParser(userAgent[i]); UserAgent ua= (UserAgent)
    143       parser.parse(); System.out.println("encoded = " + ua.encode()); }
    144        }
    145 
    146 }
    147