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*/
26package gov.nist.javax.sip.parser;
27
28import gov.nist.core.Token;
29import gov.nist.javax.sip.header.*;
30import 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 */
42public 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