1package gov.nist.javax.sip.parser.ims;
2/*
3* Conditions Of Use
4*
5* This software was developed by employees of the National Institute of
6* Standards and Technology (NIST), an agency of the Federal Government.
7* Pursuant to title 15 Untied States Code Section 105, works of NIST
8* employees are not subject to copyright protection in the United States
9* and are considered to be in the public domain.  As a result, a formal
10* license is not needed to use the software.
11*
12* This software is provided by NIST as a service and is expressly
13* provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
14* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
15* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
16* AND DATA ACCURACY.  NIST does not warrant or make any representations
17* regarding the use of the software or the results thereof, including but
18* not limited to the correctness, accuracy, reliability or usefulness of
19* the software.
20*
21* Permission to use this software is contingent upon your acceptance
22* of the terms of this agreement
23*
24* .
25*
26*/
27import java.text.ParseException;
28
29import javax.sip.InvalidArgumentException;
30
31import gov.nist.javax.sip.header.SIPHeader;
32import gov.nist.javax.sip.header.ims.PPreferredService;
33import gov.nist.javax.sip.header.ims.ParameterNamesIms;
34import gov.nist.javax.sip.parser.HeaderParser;
35import gov.nist.javax.sip.parser.Lexer;
36import gov.nist.javax.sip.parser.TokenTypes;
37/**
38 *
39 * @author aayush.bhatnagar
40 * Rancore Technologies Pvt Ltd, Mumbai India.
41 *
42 * Parse this:
43 * P-Preferred-Service: urn:urn-7:3gpp-service.exampletelephony.version1
44 *
45 */
46public class PPreferredServiceParser extends HeaderParser implements TokenTypes{
47
48    protected PPreferredServiceParser(Lexer lexer) {
49        super(lexer);
50    }
51
52    public PPreferredServiceParser(String pps)
53    {
54        super(pps);
55    }
56
57    /**
58     * "The URN consists of a hierarchical service identifier or application
59     * identifier, with a sequence of labels separated by periods.The left-most label is
60     * the most significant one and is called 'top-level service
61     * identifier', while names to the right are called 'sub-services' or
62     * 'sub-applications'.
63     *
64     * For any given service identifier, labels can be removed right-to-left and
65     * the resulting URN is still valid, referring a more generic
66     * service, with the exception of the top-level service identifier
67     * and possibly the first sub-service or sub-application identifier.
68     *
69     *  Labels cannot be removed beyond a defined basic service, for
70     *  example, the label w.x may define a service, but the label w may
71     *  only define an assignment authority for assigning subsequent
72     *  values and not define a service in its own right.  In other words,
73     *  if a service identifier 'w.x.y.z' exists, the URNs 'w.x' and
74     *  'w.x.y' are also valid service identifiers, but w may not be a
75     *  valid service identifier if it merely defines who is responsible"
76     *
77     * TODO: PLEASE VALIDATE MY UNDERSTANDING OF THE ABOVE TEXT :)
78     * @ranga: Please validate my understanding of the above text in the draft :)
79     *         This last para is a little ambiguous.I will only check that atleast
80     *         1 sub-service or 1 sub-application is present in the URN declaration.
81     *         If not, I throw an exception. I thought of not throwing an exception
82     *         and returning whatever was encoded..but the resultant encoding wont
83     *         make sense. It would be something like-->
84     *         urn:urn-7:3gpp-service OR urn:urn-7:3gpp-application alone with no sub-services
85     *         or sub-applications. This is bound to cause an error at the recepient later.
86     *
87     * Sub-service and Application identifiers are not maintained by IANA and
88     * are organization/application dependent (Section 8.2). So we cannot gurantee what lies
89     * beyond the first sub-service or sub-application identifier. It should be the responsibility
90     * of the application to make sense of the entire URN holistically. We can only check for the
91     * standardized part as per the ABNF.
92     */
93    public SIPHeader parse() throws ParseException {
94        if(debug)
95            dbg_enter("PPreferredServiceParser.parse");
96        try
97        {
98
99        this.lexer.match(TokenTypes.P_PREFERRED_SERVICE);
100        this.lexer.SPorHT();
101        this.lexer.match(':');
102        this.lexer.SPorHT();
103
104        PPreferredService pps = new PPreferredService();
105        String urn = this.lexer.getBuffer();
106        if(urn.contains(ParameterNamesIms.SERVICE_ID)){
107
108           if(urn.contains(ParameterNamesIms.SERVICE_ID_LABEL))
109                   {
110                    String serviceID = urn.split(ParameterNamesIms.SERVICE_ID_LABEL+".")[1];
111
112                     if(serviceID.trim().equals(""))
113                        try {
114                            throw new InvalidArgumentException("URN should atleast have one sub-service");
115                        } catch (InvalidArgumentException e) {
116
117                            e.printStackTrace();
118                        }
119                        else
120                    pps.setSubserviceIdentifiers(serviceID);
121                   }
122           else if(urn.contains(ParameterNamesIms.APPLICATION_ID_LABEL))
123              {
124               String appID = urn.split(ParameterNamesIms.APPLICATION_ID_LABEL)[1];
125               if(appID.trim().equals(""))
126                    try {
127                        throw new InvalidArgumentException("URN should atleast have one sub-application");
128                    } catch (InvalidArgumentException e) {
129                        e.printStackTrace();
130                    }
131                    else
132                  pps.setApplicationIdentifiers(appID);
133              }
134           else
135           {
136               try {
137                throw new InvalidArgumentException("URN is not well formed");
138
139            } catch (InvalidArgumentException e) {
140                e.printStackTrace();
141                    }
142                  }
143          }
144
145            super.parse();
146            return pps;
147        }
148        finally{
149            if(debug)
150                dbg_enter("PPreferredServiceParser.parse");
151        }
152
153    }
154}
155