001 package org.apache.ojb.odmg;
002
003 /* Copyright 2002-2005 The Apache Software Foundation
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 import org.apache.ojb.broker.OJBRuntimeException;
019 import org.apache.ojb.broker.PBFactoryException;
020 import org.apache.ojb.broker.PBKey;
021 import org.apache.ojb.broker.PersistenceBroker;
022 import org.apache.ojb.broker.PersistenceBrokerFactory;
023 import org.apache.ojb.broker.util.logging.Logger;
024 import org.apache.ojb.broker.util.logging.LoggerFactory;
025 import org.odmg.Transaction;
026
027 public final class PBCapsule
028 {
029 private static Logger log = LoggerFactory.getLogger(PBCapsule.class);
030
031 PersistenceBroker broker;
032 PBKey pbKey;
033 Transaction tx;
034 boolean needsTxCommit = false;
035 boolean needsPBCommit = false;
036 boolean isIlleagal = false;
037
038 public PBCapsule(final PBKey pbKey, final Transaction tx)
039 {
040 this.tx = tx;
041 this.pbKey = pbKey;
042 prepare();
043 }
044
045 public PersistenceBroker getBroker()
046 {
047 if(isIlleagal) throw new OJBRuntimeException("You could not reuse PBCapsule after destroy");
048 return broker;
049 }
050
051 private void prepare()
052 {
053 if(isIlleagal) throw new OJBRuntimeException("You could not reuse PBCapsule after destroy");
054 // we allow queries even if no ODMG transaction is running.
055 // thus we use direct access to PBF via the given PBKey to
056 // get a PB instance
057 if (tx == null)
058 {
059 if (log.isDebugEnabled())
060 log.debug("No running transaction found, try to get " +
061 "PersistenceBroker instance via PBKey " + pbKey);
062 broker = obtainBroker();
063 // begin tx on the PB instance
064 if (!broker.isInTransaction())
065 {
066 broker.beginTransaction();
067 needsPBCommit = true;
068 }
069 }
070 else
071 {
072 // we allow to work with unopened transactions.
073 // we assume that such a tx is to be closed after performing the query
074 if (!tx.isOpen())
075 {
076 tx.begin();
077 needsTxCommit = true;
078 }
079 // obtain a broker instance from the current transaction
080 broker = ((HasBroker) tx).getBroker();
081 }
082 }
083
084 public void destroy()
085 {
086 if (needsTxCommit)
087 {
088 if (log.isDebugEnabled()) log.debug("Indicated to commit tx");
089 tx.commit();
090 }
091 else if (needsPBCommit)
092 {
093 if (log.isDebugEnabled()) log.debug("Indicated to commit PersistenceBroker");
094 try
095 {
096 broker.commitTransaction();
097 }
098 finally
099 {
100 if (broker != null) broker.close();
101 }
102 }
103 isIlleagal = true;
104 needsTxCommit = false;
105 needsPBCommit = false;
106 }
107
108 /**
109 * Used to get PB, when no tx is running.
110 */
111 private PersistenceBroker obtainBroker()
112 {
113 PersistenceBroker _broker;
114 try
115 {
116 if (pbKey == null)
117 {
118 //throw new OJBRuntimeException("Not possible to do action, cause no tx runnning and no PBKey is set");
119 log.warn("No tx runnning and PBKey is null, try to use the default PB");
120 _broker = PersistenceBrokerFactory.defaultPersistenceBroker();
121 }
122 else
123 {
124 _broker = PersistenceBrokerFactory.createPersistenceBroker(pbKey);
125 }
126 }
127 catch (PBFactoryException e)
128 {
129 log.error("Could not obtain PB for PBKey " + pbKey, e);
130 throw new OJBRuntimeException("Unexpected micro-kernel exception", e);
131 }
132 return _broker;
133 }
134 }