1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.dbcp2.managed;
18
19 import java.sql.Connection;
20 import java.sql.SQLException;
21 import java.util.Map;
22 import java.util.Objects;
23 import java.util.WeakHashMap;
24
25 import javax.transaction.SystemException;
26 import javax.transaction.Transaction;
27 import javax.transaction.TransactionManager;
28 import javax.transaction.TransactionSynchronizationRegistry;
29 import javax.transaction.xa.XAResource;
30
31 import org.apache.commons.dbcp2.DelegatingConnection;
32
33 /**
34 * TransactionRegistry tracks Connections and XAResources in a transacted environment for a single XAConnectionFactory.
35 * <p>
36 * The TransactionRegistry hides the details of transaction processing from the existing DBCP pooling code, and gives
37 * the ManagedConnection a way to enlist connections in a transaction, allowing for the maximal rescue of DBCP.
38 * </p>
39 *
40 * @since 2.0
41 */
42 public class TransactionRegistry {
43 private final TransactionManager transactionManager;
44 private final Map<Transaction, TransactionContext> caches = new WeakHashMap<>();
45 private final Map<Connection, XAResource> xaResources = new WeakHashMap<>();
46 private final TransactionSynchronizationRegistry transactionSynchronizationRegistry;
47
48 /**
49 * Provided for backwards compatibility
50 * @param transactionManager the transaction manager used to enlist connections
51 */
52 public TransactionRegistry(final TransactionManager transactionManager) {
53 this (transactionManager, null);
54 }
55
56 /**
57 * Creates a TransactionRegistry for the specified transaction manager.
58 *
59 * @param transactionManager
60 * the transaction manager used to enlist connections.
61 * @param transactionSynchronizationRegistry
62 * The optional TSR to register synchronizations with
63 * @since 2.6.0
64 */
65 public TransactionRegistry(final TransactionManager transactionManager, final TransactionSynchronizationRegistry transactionSynchronizationRegistry) {
66 this.transactionManager = transactionManager;
67 this.transactionSynchronizationRegistry = transactionSynchronizationRegistry;
68 }
69
70 /**
71 * Gets the active TransactionContext or null if not Transaction is active.
72 *
73 * @return The active TransactionContext or null if no Transaction is active.
74 * @throws SQLException
75 * Thrown when an error occurs while fetching the transaction.
76 */
77 public TransactionContext getActiveTransactionContext() throws SQLException {
78 Transaction transaction = null;
79 try {
80 transaction = transactionManager.getTransaction();
81
82 // was there a transaction?
83 if (transaction == null) {
84 return null;
85 }
86
87 // This is the transaction on the thread so no need to check its status - we should try to use it and
88 // fail later based on the subsequent status
89 } catch (final SystemException e) {
90 throw new SQLException("Unable to determine current transaction ", e);
91 }
92
93 // register the context (or create a new one)
94 synchronized (this) {
95 return caches.computeIfAbsent(transaction, k -> new TransactionContext(this, k, transactionSynchronizationRegistry));
96 }
97 }
98
99 private Connection getConnectionKey(final Connection connection) {
100 final Connection result;
101 if (connection instanceof DelegatingConnection) {
102 result = ((DelegatingConnection<?>) connection).getInnermostDelegateInternal();
103 } else {
104 result = connection;
105 }
106 return result;
107 }
108
109 /**
110 * Gets the XAResource registered for the connection.
111 *
112 * @param connection
113 * the connection
114 * @return The XAResource registered for the connection; never null.
115 * @throws SQLException
116 * Thrown when the connection does not have a registered XAResource.
117 */
118 public synchronized XAResource getXAResource(final Connection connection) throws SQLException {
119 Objects.requireNonNull(connection, "connection");
120 final Connection key = getConnectionKey(connection);
121 final XAResource xaResource = xaResources.get(key);
122 if (xaResource == null) {
123 throw new SQLException("Connection does not have a registered XAResource " + connection);
124 }
125 return xaResource;
126 }
127
128 /**
129 * Registers the association between a Connection and a XAResource. When a connection is enlisted in a transaction,
130 * it is actually the XAResource that is given to the transaction manager.
131 *
132 * @param connection
133 * The JDBC connection.
134 * @param xaResource
135 * The XAResource which managed the connection within a transaction.
136 */
137 public synchronized void registerConnection(final Connection connection, final XAResource xaResource) {
138 Objects.requireNonNull(connection, "connection");
139 Objects.requireNonNull(xaResource, "xaResource");
140 xaResources.put(connection, xaResource);
141 }
142
143 /**
144 * Unregisters a destroyed connection from {@link TransactionRegistry}.
145 *
146 * @param connection
147 * A destroyed connection from {@link TransactionRegistry}.
148 */
149 public synchronized void unregisterConnection(final Connection connection) {
150 xaResources.remove(getConnectionKey(connection));
151 }
152 }