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1
43 package org.exolab.jms.persistence;
44
45 import java.sql.Connection  ;
46 import java.sql.PreparedStatement ;
47 import java.sql.ResultSet ;
48 import java.util.HashMap ;
49 import java.util.Iterator ;
50 import java.util.Vector ;
51
52 import org.exolab.jms.client.JmsDestination;
53 import org.exolab.jms.client.JmsQueue;
54 import org.exolab.jms.client.JmsTopic;
55
56
57
66 class Destinations {
67
68
71 private HashMap _destinations;
72
73
76 private HashMap _ids;
77
78
81 private static Destinations _instance;
82
83
86 private static final Object _block = new Object ();
87
88
92 private static final String DESTINATION_ID_SEED = "destinationId";
93
94
99 private Destinations()
100 throws PersistenceException {
101
102 _destinations = new HashMap ();
103 _ids = new HashMap ();
104 }
105
106
114 public static Destinations instance() {
115 return _instance;
116 }
117
118
125 public static Destinations initialise(Connection connection)
126 throws PersistenceException {
127
128 if (_instance == null) {
129 synchronized (_block) {
130 if (_instance == null) {
131 _instance = new Destinations();
132 _instance.load(connection);
133 }
134 }
135 }
136 return _instance;
137 }
138
139
147 public synchronized void add(Connection connection,
148 JmsDestination destination)
149 throws PersistenceException {
150
151 PreparedStatement insert = null;
152 try {
153 long Id = SeedGenerator.instance().next(connection,
154 DESTINATION_ID_SEED);
155 boolean isQueue = (destination instanceof JmsQueue);
156
157 insert = connection.prepareStatement(
158 "insert into destinations (name, isqueue, destinationid) "
159 + "values (?, ?, ?)");
160 insert.setString(1, destination.getName());
161 insert.setBoolean(2, isQueue);
162 insert.setLong(3, Id);
163 insert.executeUpdate();
164 cache(destination, Id);
165 } catch (Exception error) {
166 throw new PersistenceException("Destinations.add failed with " +
167 error.toString());
168 } finally {
169 SQLHelper.close(insert);
170 }
171 }
172
173
182 public synchronized boolean remove(Connection connection,
183 JmsDestination destination)
184 throws PersistenceException {
185
186 boolean success = false;
187 PreparedStatement deleteDestinations = null;
188 PreparedStatement deleteMessages = null;
189 PreparedStatement deleteConsumers = null;
190 PreparedStatement deleteMessageHandles = null;
191
192 Pair pair = (Pair) _destinations.get(destination.getName());
193 if (pair != null) {
194 try {
195 deleteDestinations = connection.prepareStatement(
196 "delete from destinations where name=?");
197 deleteDestinations.setString(1, destination.getName());
198
199 deleteMessages = connection.prepareStatement(
200 "delete from messages where destinationId=?");
201 deleteMessages.setLong(1, pair.Id);
202
203 deleteMessageHandles = connection.prepareStatement(
204 "delete from message_handles where destinationId=?");
205 deleteMessageHandles.setLong(1, pair.Id);
206
207 deleteConsumers = connection.prepareStatement(
208 "delete from consumers where destinationId=?");
209 deleteConsumers.setLong(1, pair.Id);
210
211
212 deleteDestinations.executeUpdate();
213 deleteMessages.executeUpdate();
214 deleteMessageHandles.executeUpdate();
215 deleteConsumers.executeUpdate();
216
217 Consumers.instance().removeCached(pair.Id);
218 _destinations.remove(destination.getName());
219 _ids.remove(new Long (pair.Id));
220 success = true;
221 } catch (Exception error) {
222 throw new PersistenceException("Destinations.remove failed " +
223 error.toString());
224 } finally {
225 SQLHelper.close(deleteDestinations);
226 SQLHelper.close(deleteMessages);
227 SQLHelper.close(deleteConsumers);
228 SQLHelper.close(deleteMessageHandles);
229 }
230 }
231
232 return success;
233 }
234
235
241 public synchronized JmsDestination get(String name) {
242 Pair pair = (Pair) _destinations.get(name);
243 return (pair != null) ? pair.destination : null;
244 }
245
246
252 public synchronized JmsDestination get(long id) {
253 Pair pair = (Pair) _ids.get(new Long (id));
254 return (pair != null) ? pair.destination : null;
255 }
256
257
263 public synchronized long getId(String name) {
264 Pair pair = (Pair) _destinations.get(name);
265 return (pair != null) ? pair.Id : 0;
266 }
267
268
273 public synchronized Vector getNames() {
274 Vector result = new Vector (_destinations.size());
276 Iterator iter = _destinations.keySet().iterator();
277 while (iter.hasNext()) {
278 result.add((String ) iter.next());
279 }
280
281 return result;
282 }
283
284
289 public synchronized Vector getDestinations() {
290 Vector result = new Vector (_destinations.size());
292 Iterator iter = _destinations.values().iterator();
293 while (iter.hasNext()) {
294 result.add(((Pair) iter.next()).destination);
295 }
296
297 return result;
298 }
299
300
303 public synchronized void close() {
304 _destinations.clear();
305 _destinations = null;
306
307 _ids.clear();
308 _ids = null;
309
310 _instance = null;
311 }
312
313
320 private void load(Connection connection)
321 throws PersistenceException {
322
323 PreparedStatement select = null;
324 ResultSet set = null;
325 try {
326 select = connection.prepareStatement(
327 "select name, isqueue, destinationid from destinations");
328
329 set = select.executeQuery();
330 String name = null;
331 boolean isQueue = false;
332 JmsDestination destination = null;
333 long Id = 0;
334 while (set.next()) {
335 name = set.getString(1);
336 isQueue = set.getBoolean(2);
337 destination = (isQueue)
338 ? (JmsDestination) new JmsQueue(name)
339 : (JmsDestination) new JmsTopic(name);
340 Id = set.getLong(3);
341 destination.setPersistent(true);
342 cache(destination, Id);
343 }
344 } catch (Exception exception) {
345 throw new PersistenceException("Failed to load destinations",
346 exception);
347 } finally {
348 SQLHelper.close(set);
349 SQLHelper.close(select);
350 }
351 }
352
353
359 private void cache(JmsDestination destination, long Id) {
360 Pair pair = new Pair(destination, Id);
361
362 _destinations.put(destination.getName(), pair);
363 _ids.put(new Long (Id), pair);
364 }
365
366
367
371 private static class Pair {
372
373 public Pair(JmsDestination destination, long Id) {
374 this.destination = destination;
375 this.Id = Id;
376 }
377
378 public JmsDestination destination;
379 public long Id;
380 }
381 }
382 |
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