/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.dbcp.cpdsadapter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.Vector;
import javax.sql.ConnectionEvent;
import javax.sql.ConnectionEventListener;
import javax.sql.PooledConnection;
import org.apache.commons.dbcp.DelegatingConnection;
import org.apache.commons.dbcp.DelegatingPreparedStatement;
import org.apache.commons.dbcp.SQLNestedException;
import org.apache.commons.pool.KeyedObjectPool;
import org.apache.commons.pool.KeyedPoolableObjectFactory;
/**
* Implementation of PooledConnection that is returned by
* PooledConnectionDataSource.
*
* @author John D. McNally
* @version $Revision: 479137 $ $Date: 2006-11-25 08:51:48 -0700 (Sat, 25 Nov 2006) $
*/
class PooledConnectionImpl
implements PooledConnection, KeyedPoolableObjectFactory {
private static final String CLOSED
= "Attempted to use PooledConnection after closed() was called.";
/**
* The JDBC database connection that represents the physical db connection.
*/
private Connection connection = null;
/**
* A DelegatingConnection used to create a PoolablePreparedStatementStub
*/
private DelegatingConnection delegatingConnection = null;
/**
* The JDBC database logical connection.
*/
private Connection logicalConnection = null;
/**
* ConnectionEventListeners
*/
private Vector eventListeners;
/**
* flag set to true, once close() is called.
*/
boolean isClosed;
/** My pool of {*link PreparedStatement}s. */
protected KeyedObjectPool pstmtPool = null;
/**
* Wrap the real connection.
*/
PooledConnectionImpl(Connection connection, KeyedObjectPool pool) {
this.connection = connection;
if (connection instanceof DelegatingConnection) {
this.delegatingConnection = (DelegatingConnection) connection;
} else {
this.delegatingConnection = new DelegatingConnection(connection);
}
eventListeners = new Vector();
isClosed = false;
if (pool != null) {
pstmtPool = pool;
pstmtPool.setFactory(this);
}
}
/**
* Add an event listener.
*/
public void addConnectionEventListener(ConnectionEventListener listener) {
if (!eventListeners.contains(listener)) {
eventListeners.add(listener);
}
}
/**
* Closes the physical connection and marks this
* <code>PooledConnection</code> so that it may not be used
* to generate any more logical <code>Connection</code>s.
*
* @exception SQLException if an error occurs
*/
public void close() throws SQLException {
assertOpen();
isClosed = true;
try {
if (pstmtPool != null) {
try {
pstmtPool.close();
} finally {
pstmtPool = null;
}
}
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new SQLNestedException("Cannot close connection (return to pool failed)", e);
} finally {
try {
connection.close();
} finally {
connection = null;
}
}
}
/**
* Throws an SQLException, if isClosed() is true
*/
private void assertOpen() throws SQLException {
if (isClosed) {
throw new SQLException(CLOSED);
}
}
/**
* Returns a JDBC connection.
*
* @return The database connection.
*/
public Connection getConnection() throws SQLException {
assertOpen();
// make sure the last connection is marked as closed
if (logicalConnection != null && !logicalConnection.isClosed()) {
// should notify pool of error so the pooled connection can
// be removed !FIXME!
throw new SQLException("PooledConnection was reused, without"
+ "its previous Connection being closed.");
}
// the spec requires that this return a new Connection instance.
logicalConnection = new ConnectionImpl(this, connection);
return logicalConnection;
}
/**
* Remove an event listener.
*/
public void removeConnectionEventListener(
ConnectionEventListener listener) {
eventListeners.remove(listener);
}
/**
* Closes the physical connection and checks that the logical connection
* was closed as well.
*/
protected void finalize() throws Throwable {
// Closing the Connection ensures that if anyone tries to use it,
// an error will occur.
try {
connection.close();
} catch (Exception ignored) {
}
// make sure the last connection is marked as closed
if (logicalConnection != null && !logicalConnection.isClosed()) {
throw new SQLException("PooledConnection was gc'ed, without"
+ "its last Connection being closed.");
}
}
/**
* sends a connectionClosed event.
*/
void notifyListeners() {
ConnectionEvent event = new ConnectionEvent(this);
Iterator i = eventListeners.iterator();
while (i.hasNext()) {
((ConnectionEventListener) i.next()).connectionClosed(event);
}
}
// -------------------------------------------------------------------
// The following code implements a PreparedStatement pool
/**
* Create or obtain a {*link PreparedStatement} from my pool.
* @return a {*link PoolablePreparedStatement}
*/
PreparedStatement prepareStatement(String sql) throws SQLException {
if (pstmtPool == null) {
return connection.prepareStatement(sql);
} else {
try {
return (PreparedStatement)
pstmtPool.borrowObject(createKey(sql));
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new SQLNestedException("Borrow prepareStatement from pool failed", e);
}
}
}
/**
* Create or obtain a {*link PreparedStatement} from my pool.
* @return a {*link PoolablePreparedStatement}
*/
PreparedStatement prepareStatement(String sql, int resultSetType,
int resultSetConcurrency)
throws SQLException {
if (pstmtPool == null) {
return connection.prepareStatement(sql, resultSetType, resultSetConcurrency);
} else {
try {
return (PreparedStatement) pstmtPool.borrowObject(
createKey(sql,resultSetType,resultSetConcurrency));
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new SQLNestedException("Borrow prepareStatement from pool failed", e);
}
}
}
/**
* Create a {*link PooledConnectionImpl.PStmtKey} for the given arguments.
*/
protected Object createKey(String sql, int resultSetType,
int resultSetConcurrency) {
return new PStmtKey(normalizeSQL(sql), resultSetType,
resultSetConcurrency);
}
/**
* Create a {*link PooledConnectionImpl.PStmtKey} for the given arguments.
*/
protected Object createKey(String sql) {
return new PStmtKey(normalizeSQL(sql));
}
/**
* Normalize the given SQL statement, producing a
* cannonical form that is semantically equivalent to the original.
*/
protected String normalizeSQL(String sql) {
return sql.trim();
}
/**
* My {*link KeyedPoolableObjectFactory} method for creating
* {*link PreparedStatement}s.
* @param obj the key for the {*link PreparedStatement} to be created
*/
public Object makeObject(Object obj) throws Exception {
if (null == obj || !(obj instanceof PStmtKey)) {
throw new IllegalArgumentException();
} else {
// _openPstmts++;
PStmtKey key = (PStmtKey)obj;
if (null == key._resultSetType
&& null == key._resultSetConcurrency) {
return new PoolablePreparedStatementStub(
connection.prepareStatement(key._sql),
key, pstmtPool, delegatingConnection);
} else {
return new PoolablePreparedStatementStub(
connection.prepareStatement(key._sql,
key._resultSetType.intValue(),
key._resultSetConcurrency.intValue()),
key, pstmtPool, delegatingConnection);
}
}
}
/**
* My {*link KeyedPoolableObjectFactory} method for destroying
* {*link PreparedStatement}s.
* @param key ignored
* @param obj the {*link PreparedStatement} to be destroyed.
*/
public void destroyObject(Object key, Object obj) throws Exception {
//_openPstmts--;
if (obj instanceof DelegatingPreparedStatement) {
((DelegatingPreparedStatement) obj).getInnermostDelegate().close();
} else {
((PreparedStatement) obj).close();
}
}
/**
* My {*link KeyedPoolableObjectFactory} method for validating
* {*link PreparedStatement}s.
* @param key ignored
* @param obj ignored
* @return <tt>true</tt>
*/
public boolean validateObject(Object key, Object obj) {
return true;
}
/**
* My {*link KeyedPoolableObjectFactory} method for activating
* {*link PreparedStatement}s.
* @param key ignored
* @param obj ignored
*/
public void activateObject(Object key, Object obj) throws Exception {
((PoolablePreparedStatementStub) obj).activate();
}
/**
* My {*link KeyedPoolableObjectFactory} method for passivating
* {*link PreparedStatement}s. Currently invokes {*link PreparedStatement#clearParameters}.
* @param key ignored
* @param obj a {*link PreparedStatement}
*/
public void passivateObject(Object key, Object obj) throws Exception {
((PreparedStatement) obj).clearParameters();
((PoolablePreparedStatementStub) obj).passivate();
}
/**
* A key uniquely identifying {*link PreparedStatement}s.
*/
class PStmtKey {
protected String _sql = null;
protected Integer _resultSetType = null;
protected Integer _resultSetConcurrency = null;
PStmtKey(String sql) {
_sql = sql;
}
PStmtKey(String sql, int resultSetType, int resultSetConcurrency) {
_sql = sql;
_resultSetType = new Integer(resultSetType);
_resultSetConcurrency = new Integer(resultSetConcurrency);
}
public boolean equals(Object that) {
try {
PStmtKey key = (PStmtKey) that;
return(((null == _sql && null == key._sql) || _sql.equals(key._sql)) &&
((null == _resultSetType && null == key._resultSetType) || _resultSetType.equals(key._resultSetType)) &&
((null == _resultSetConcurrency && null == key._resultSetConcurrency) || _resultSetConcurrency.equals(key._resultSetConcurrency))
);
} catch (ClassCastException e) {
return false;
} catch (NullPointerException e) {
return false;
}
}
public int hashCode() {
return(null == _sql ? 0 : _sql.hashCode());
}
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append("PStmtKey: sql=");
buf.append(_sql);
buf.append(", resultSetType=");
buf.append(_resultSetType);
buf.append(", resultSetConcurrency=");
buf.append(_resultSetConcurrency);
return buf.toString();
}
}
}