001 /**
002 *
003 * Copyright 2004 Hiram Chirino
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 package org.activemq.service.impl;
019
020 import java.util.ArrayList;
021 import java.util.Iterator;
022
023 import javax.transaction.xa.XAException;
024
025 import org.activemq.service.Transaction;
026 import org.activemq.service.TransactionTask;
027
028 /**
029 * Keeps track of all the actions the need to be done when
030 * a transaction does a commit or rollback.
031 *
032 * @version $Revision: 1.1.1.1 $
033 */
034 public abstract class AbstractTransaction implements Transaction {
035
036 static final public byte START_STATE = 0; // can go to: 1,2,3
037 static final public byte IN_USE_STATE = 1; // can go to: 2,3
038 static final public byte PREPARED_STATE = 2; // can go to: 3
039 static final public byte FINISHED_STATE = 3;
040
041
042 private ArrayList prePrepareTasks = new ArrayList();
043 private ArrayList postCommitTasks = new ArrayList();
044 private ArrayList postRollbackTasks = new ArrayList();
045 private byte state = START_STATE;
046
047 public byte getState() {
048 return state;
049 }
050
051 public void setState(byte state) {
052 this.state = state;
053 }
054
055 public void addPostCommitTask(TransactionTask r) {
056 postCommitTasks.add(r);
057 if (state == START_STATE) {
058 state = IN_USE_STATE;
059 }
060 }
061
062 public void addPostRollbackTask(TransactionTask r) {
063 postRollbackTasks.add(r);
064 if (state == START_STATE) {
065 state = IN_USE_STATE;
066 }
067 }
068
069 public void addPrePrepareTask(TransactionTask r) {
070 prePrepareTasks.add(r);
071 if (state == START_STATE) {
072 state = IN_USE_STATE;
073 }
074 }
075
076 public void prePrepare() throws Throwable {
077
078 // Is it ok to call prepare now given the state of the
079 // transaction?
080 switch (state) {
081 case START_STATE:
082 case IN_USE_STATE:
083 break;
084 default:
085 XAException xae = new XAException("Prepare cannot be called now.");
086 xae.errorCode = XAException.XAER_PROTO;
087 throw xae;
088 }
089
090 // Run the prePrepareTasks
091 for (Iterator iter = prePrepareTasks.iterator(); iter.hasNext();) {
092 TransactionTask r = (TransactionTask) iter.next();
093 r.execute();
094 }
095 }
096
097 protected void postCommit() throws Throwable {
098 // Run the postCommitTasks
099 for (Iterator iter = postCommitTasks.iterator(); iter.hasNext();) {
100 TransactionTask r = (TransactionTask) iter.next();
101 r.execute();
102 }
103 }
104
105 public void postRollback() throws Throwable {
106 // Run the postRollbackTasks
107 for (Iterator iter = postRollbackTasks.iterator(); iter.hasNext();) {
108 TransactionTask r = (TransactionTask) iter.next();
109 r.execute();
110 }
111 }
112
113 public String toString() {
114 return super.toString() + "[prePrepares=" + prePrepareTasks + "; postCommits=" + postCommitTasks
115 + "; postRollbacks=" + postRollbackTasks + "]";
116 }
117
118 }