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Java > Open Source Codes > org > apache > commons > net > nntp > NewGroupsOrNewsQuery


1 /*
2  * Copyright 2001-2005 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.net.nntp;
17
18 import java.util.Calendar JavaDoc;
19
20 /***
21  * The NewGroupsOrNewsQuery class. This is used to issue NNTP NEWGROUPS and
22  * NEWNEWS queries, implemented by
23  * {@link org.apache.commons.net.nntp.NNTPClient#listNewNewsgroups listNewNewsGroups }
24  * and
25  * {@link org.apache.commons.net.nntp.NNTPClient#listNewNews listNewNews }
26  * respectively. It prevents you from having to format
27  * date, time, distribution, and newgroup arguments.
28  * <p>
29  * You might use the class as follows:
30  * <pre>
31  * query = new NewsGroupsOrNewsQuery(new GregorianCalendar(97, 11, 15), false);
32  * query.addDistribution("comp");
33  * NewsgroupInfo[] newsgroups = client.listNewgroups(query);
34  * </pre>
35  * This will retrieve the list of newsgroups starting with the comp.
36  * distribution prefix created since midnight 11/15/97.
37  * <p>
38  * <p>
39  * @author Daniel F. Savarese
40  * @see NNTPClient
41  ***/
42
43 public final class NewGroupsOrNewsQuery
44 {
45     private String JavaDoc __date, __time;
46     private StringBuffer JavaDoc __distributions;
47     private StringBuffer JavaDoc __newsgroups;
48     private boolean __isGMT;
49
50
51     /***
52      * Creates a new query using the given time as a reference point.
53      * <p>
54      * @param date The date since which new groups or news have arrived.
55      * @param gmt True if the date should be considered as GMT, false if not.
56      ***/
57     public NewGroupsOrNewsQuery(Calendar JavaDoc date, boolean gmt)
58     {
59         int num;
60         String JavaDoc str;
61         StringBuffer JavaDoc buffer;
62
63         __distributions = null;
64         __newsgroups = null;
65         __isGMT = gmt;
66
67         buffer = new StringBuffer JavaDoc();
68
69         // Get year
70 num = date.get(Calendar.YEAR);
71         str = Integer.toString(num);
72         num = str.length();
73
74         if (num >= 2)
75             buffer.append(str.substring(num - 2));
76         else
77             buffer.append("00");
78
79         // Get month
80 num = date.get(Calendar.MONTH) + 1;
81         str = Integer.toString(num);
82         num = str.length();
83
84         if (num == 1)
85         {
86             buffer.append('0');
87             buffer.append(str);
88         }
89         else if (num == 2)
90             buffer.append(str);
91         else
92             buffer.append("01");
93
94         // Get day
95 num = date.get(Calendar.DAY_OF_MONTH);
96         str = Integer.toString(num);
97         num = str.length();
98
99         if (num == 1)
100         {
101             buffer.append('0');
102             buffer.append(str);
103         }
104         else if (num == 2)
105             buffer.append(str);
106         else
107             buffer.append("01");
108
109         __date = buffer.toString();
110
111         buffer.setLength(0);
112
113         // Get hour
114 num = date.get(Calendar.HOUR_OF_DAY);
115         str = Integer.toString(num);
116         num = str.length();
117
118         if (num == 1)
119         {
120             buffer.append('0');
121             buffer.append(str);
122         }
123         else if (num == 2)
124             buffer.append(str);
125         else
126             buffer.append("00");
127
128         // Get minutes
129 num = date.get(Calendar.MINUTE);
130         str = Integer.toString(num);
131         num = str.length();
132
133         if (num == 1)
134         {
135             buffer.append('0');
136             buffer.append(str);
137         }
138         else if (num == 2)
139             buffer.append(str);
140         else
141             buffer.append("00");
142
143
144         // Get seconds
145 num = date.get(Calendar.SECOND);
146         str = Integer.toString(num);
147         num = str.length();
148
149         if (num == 1)
150         {
151             buffer.append('0');
152             buffer.append(str);
153         }
154         else if (num == 2)
155             buffer.append(str);
156         else
157             buffer.append("00");
158
159         __time = buffer.toString();
160     }
161
162
163     /***
164      * Add a newsgroup to the list of newsgroups being queried. Newsgroups
165      * added this way are only meaningful to the NEWNEWS command. Newsgroup
166      * names may include the <code> * </code> wildcard, as in
167      * <code>comp.lang.* </code> or <code> comp.lang.java.* </code>. Adding
168      * at least one newsgroup is mandatory for the NEWNEWS command.
169      * <p>
170      * @param newsgroup The newsgroup to add to the list of groups to be
171      * checked for new news.
172      ***/
173     public void addNewsgroup(String JavaDoc newsgroup)
174     {
175         if (__newsgroups != null)
176             __newsgroups.append(',');
177         else
178             __newsgroups = new StringBuffer JavaDoc();
179         __newsgroups.append(newsgroup);
180     }
181
182
183     /***
184      * Add a newsgroup to the list of newsgroups being queried, but indicate
185      * that group should not be checked for new news. Newsgroups
186      * added this way are only meaningful to the NEWNEWS command.
187      * Newsgroup names may include the <code> * </code> wildcard, as in
188      * <code>comp.lang.* </code> or <code> comp.lang.java.* </code>.
189      * <p>
190      * The following would create a query that searched for new news in
191      * all comp.lang.java newsgroups except for comp.lang.java.advocacy.
192      * <pre>
193      * query.addNewsgroup("comp.lang.java.*");
194      * query.omitNewsgroup("comp.lang.java.advocacy");
195      * </pre>
196      * <p>
197      * @param newsgroup The newsgroup to add to the list of groups to be
198      * checked for new news, but which should be omitted from
199      * the search for new news..
200      ***/
201     public void omitNewsgroup(String JavaDoc newsgroup)
202     {
203         addNewsgroup("!" + newsgroup);
204     }
205
206
207     /***
208      * Add a distribution group to the query. The distribution part of a
209      * newsgroup is the segment of the name preceding the first dot (e.g.,
210      * comp, alt, rec). Only those newsgroups matching one of the
211      * distributions or, in the case of NEWNEWS, an article in a newsgroup
212      * matching one of the distributions, will be reported as a query result.
213      * Adding distributions is purely optional.
214      * <p>
215      * @param distribution A distribution to add to the query.
216      ***/
217     public void addDistribution(String JavaDoc distribution)
218     {
219         if (__distributions != null)
220             __distributions.append(',');
221         else
222             __distributions = new StringBuffer JavaDoc();
223         __distributions.append(distribution);
224     }
225
226     /***
227      * Return the NNTP query formatted date (year, month, day in the form
228      * YYMMDD.
229      * <p>
230      * @return The NNTP query formatted date.
231      ***/
232     public String JavaDoc getDate()
233     {
234         return __date;
235     }
236
237     /***
238      * Return the NNTP query formatted time (hour, minutes, seconds in the form
239      * HHMMSS.
240      * <p>
241      * @return The NNTP query formatted time.
242      ***/
243     public String JavaDoc getTime()
244     {
245         return __time;
246     }
247
248     /***
249      * Return whether or not the query date should be treated as GMT.
250      * <p>
251      * @return True if the query date is to be treated as GMT, false if not.
252      ***/
253     public boolean isGMT()
254     {
255         return __isGMT;
256     }
257
258     /***
259      * Return the comma separated list of distributions. This may be null
260      * if there are no distributions.
261      * <p>
262      * @return The list of distributions, which may be null if no distributions
263      * have been specified.
264      ***/
265     public String JavaDoc getDistributions()
266     {
267         return (__distributions == null ? null : __distributions.toString());
268     }
269
270     /***
271      * Return the comma separated list of newsgroups. This may be null
272      * if there are no newsgroups
273      * <p>
274      * @return The list of newsgroups, which may be null if no newsgroups
275      * have been specified.
276      ***/
277     public String JavaDoc getNewsgroups()
278     {
279         return (__newsgroups == null ? null : __newsgroups.toString());
280     }
281 }
282
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