| 1 | /* |
| 2 | Copyright (C) 2002-2004 MySQL AB |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of version 2 of the GNU General Public License as |
| 6 | published by the Free Software Foundation. |
| 7 | |
| 8 | There are special exceptions to the terms and conditions of the GPL |
| 9 | as it is applied to this software. View the full text of the |
| 10 | exception in file EXCEPTIONS-CONNECTOR-J in the directory of this |
| 11 | software distribution. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | |
| 22 | |
| 23 | |
| 24 | */ |
| 25 | package com.mysql.jdbc.jdbc2.optional; |
| 26 | |
| 27 | import java.sql.Connection; |
| 28 | import java.sql.SQLException; |
| 29 | |
| 30 | import java.util.Enumeration; |
| 31 | import java.util.Hashtable; |
| 32 | |
| 33 | import javax.sql.ConnectionEvent; |
| 34 | import javax.sql.ConnectionEventListener; |
| 35 | import javax.sql.PooledConnection; |
| 36 | |
| 37 | /** |
| 38 | * This class is used to wrap and return a physical connection within a logical |
| 39 | * handle. It also registers and notifies ConnectionEventListeners of any |
| 40 | * ConnectionEvents |
| 41 | * |
| 42 | * @see javax.sql.PooledConnection |
| 43 | * @see org.gjt.mm.mysql.jdbc2.optional.LogicalHandle |
| 44 | * @author Todd Wolff <todd.wolff_at_prodigy.net> |
| 45 | */ |
| 46 | public class MysqlPooledConnection implements PooledConnection { |
| 47 | |
| 48 | /** |
| 49 | * The flag for an exception being thrown. |
| 50 | */ |
| 51 | public static final int CONNECTION_ERROR_EVENT = 1; |
| 52 | |
| 53 | /** |
| 54 | * The flag for a connection being closed. |
| 55 | */ |
| 56 | public static final int CONNECTION_CLOSED_EVENT = 2; |
| 57 | |
| 58 | // ~ Instance/static variables ............................................. |
| 59 | |
| 60 | private Hashtable eventListeners; |
| 61 | |
| 62 | private Connection logicalHandle; |
| 63 | |
| 64 | private com.mysql.jdbc.Connection physicalConn; |
| 65 | |
| 66 | // ~ Constructors .......................................................... |
| 67 | |
| 68 | /** |
| 69 | * Construct a new MysqlPooledConnection and set instance variables |
| 70 | * |
| 71 | * @param connection |
| 72 | * physical connection to db |
| 73 | */ |
| 74 | public MysqlPooledConnection(com.mysql.jdbc.Connection connection) { |
| 75 | this.logicalHandle = null; |
| 76 | this.physicalConn = connection; |
| 77 | this.eventListeners = new Hashtable(10); |
| 78 | } |
| 79 | |
| 80 | // ~ Methods ............................................................... |
| 81 | |
| 82 | /** |
| 83 | * Adds ConnectionEventListeners to a hash table to be used for notification |
| 84 | * of ConnectionEvents |
| 85 | * |
| 86 | * @param connectioneventlistener |
| 87 | * listener to be notified with ConnectionEvents |
| 88 | */ |
| 89 | public synchronized void addConnectionEventListener( |
| 90 | ConnectionEventListener connectioneventlistener) { |
| 91 | |
| 92 | if (this.eventListeners != null) { |
| 93 | this.eventListeners.put(connectioneventlistener, |
| 94 | connectioneventlistener); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Removes ConnectionEventListeners from hash table used for notification of |
| 100 | * ConnectionEvents |
| 101 | * |
| 102 | * @param connectioneventlistener |
| 103 | * listener to be removed |
| 104 | */ |
| 105 | public synchronized void removeConnectionEventListener( |
| 106 | ConnectionEventListener connectioneventlistener) { |
| 107 | |
| 108 | if (this.eventListeners != null) { |
| 109 | this.eventListeners.remove(connectioneventlistener); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Invoked by the container. Return a logicalHandle object that wraps a |
| 115 | * physical connection. |
| 116 | * |
| 117 | * @see java.sql.DataSource#getConnection() |
| 118 | */ |
| 119 | public synchronized Connection getConnection() throws SQLException { |
| 120 | |
| 121 | if (this.physicalConn == null) { |
| 122 | |
| 123 | SQLException sqlException = new SQLException( |
| 124 | "Physical Connection doesn't exist"); |
| 125 | callListener(CONNECTION_ERROR_EVENT, sqlException); |
| 126 | |
| 127 | return null; |
| 128 | } |
| 129 | |
| 130 | try { |
| 131 | |
| 132 | if (this.logicalHandle != null) { |
| 133 | ((ConnectionWrapper) this.logicalHandle).close(false); |
| 134 | } |
| 135 | |
| 136 | ((com.mysql.jdbc.Connection) this.physicalConn).resetServerState(); |
| 137 | |
| 138 | this.logicalHandle = new ConnectionWrapper(this, this.physicalConn); |
| 139 | } catch (SQLException sqlException) { |
| 140 | callListener(CONNECTION_ERROR_EVENT, sqlException); |
| 141 | |
| 142 | return null; |
| 143 | } |
| 144 | |
| 145 | return this.logicalHandle; |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Invoked by the container (not the client), and should close the physical |
| 150 | * connection. This will be called if the pool is destroyed or the |
| 151 | * connectionEventListener receives a connectionErrorOccurred event. |
| 152 | * |
| 153 | * @see java.sql.DataSource#close() |
| 154 | */ |
| 155 | public synchronized void close() throws SQLException { |
| 156 | if (this.physicalConn != null) { |
| 157 | this.physicalConn.close(); |
| 158 | } |
| 159 | |
| 160 | this.physicalConn = null; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Notifies all registered ConnectionEventListeners of ConnectionEvents. |
| 165 | * Instantiates a new ConnectionEvent which wraps sqlException and invokes |
| 166 | * either connectionClose or connectionErrorOccurred on listener as |
| 167 | * appropriate. |
| 168 | * |
| 169 | * @param eventType |
| 170 | * value indicating whether connectionClosed or |
| 171 | * connectionErrorOccurred called |
| 172 | * @param sqlException |
| 173 | * the exception being thrown |
| 174 | */ |
| 175 | protected synchronized void callListener(int eventType, |
| 176 | SQLException sqlException) { |
| 177 | |
| 178 | if (this.eventListeners == null) { |
| 179 | |
| 180 | return; |
| 181 | } |
| 182 | |
| 183 | Enumeration enumeration = this.eventListeners.keys(); |
| 184 | ConnectionEvent connectionevent = new ConnectionEvent(this, |
| 185 | sqlException); |
| 186 | |
| 187 | while (enumeration.hasMoreElements()) { |
| 188 | |
| 189 | ConnectionEventListener connectioneventlistener = (ConnectionEventListener) enumeration |
| 190 | .nextElement(); |
| 191 | ConnectionEventListener connectioneventlistener1 = (ConnectionEventListener) this.eventListeners |
| 192 | .get(connectioneventlistener); |
| 193 | |
| 194 | if (eventType == CONNECTION_CLOSED_EVENT) { |
| 195 | connectioneventlistener1.connectionClosed(connectionevent); |
| 196 | } else if (eventType == CONNECTION_ERROR_EVENT) { |
| 197 | connectioneventlistener1 |
| 198 | .connectionErrorOccurred(connectionevent); |
| 199 | } |
| 200 | } |
| 201 | } |
| 202 | } |