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// **********************************************************************
//
// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
class ConnectionPool
{
public synchronized void
destroy()
{
_destroyed = true;
while(_connections.size() != _nconnections)
{
try
{
wait();
}
catch(InterruptedException e)
{
}
}
while(!_connections.isEmpty())
{
java.sql.Connection conn = _connections.removeFirst();
try
{
conn.close();
}
catch(java.sql.SQLException e)
{
}
}
}
public synchronized java.sql.Connection
acquire()
{
while(_connections.isEmpty() && !_destroyed)
{
try
{
wait();
}
catch(InterruptedException e)
{
}
}
if(_destroyed)
{
return null;
}
java.sql.Connection conn = _connections.removeFirst();
try
{
boolean closed = conn.isClosed();
if(closed)
{
_logger.warning("ConnectionPool: lost connection to database");
conn = null;
}
else
{
// Probe the connection with the database.
java.sql.PreparedStatement stmt = conn.prepareStatement("SELECT 1");
java.sql.ResultSet rs = stmt.executeQuery();
stmt.close();
}
}
catch(java.sql.SQLException e)
{
java.io.StringWriter sw = new java.io.StringWriter();
java.io.PrintWriter pw = new java.io.PrintWriter(sw);
e.printStackTrace(pw);
pw.flush();
_logger.warning("ConnectionPool: lost connection to database:\n" + sw.toString());
conn = null;
}
// If the connection has been closed, or is otherwise invalid,
// we need to re-establish the connection.
while(conn == null)
{
if(_trace)
{
_logger.trace("ConnectionPool", "establishing new database connection");
}
try
{
conn = java.sql.DriverManager.getConnection(_url, _username, _password);
conn.setAutoCommit(false);
}
catch(java.sql.SQLException e)
{
java.io.StringWriter sw = new java.io.StringWriter();
java.io.PrintWriter pw = new java.io.PrintWriter(sw);
e.printStackTrace(pw);
pw.flush();
_logger.warning("ConnectionPool: database connection failed:\n" + sw.toString());
}
}
if(_trace)
{
_logger.trace("ConnectionPool", "returning connection: " + conn + " " +
_connections.size() + "/" + _nconnections + " remaining");
}
return conn;
}
public synchronized void
release(java.sql.Connection connection)
{
if(connection != null)
{
_connections.add(connection);
notifyAll();
}
}
ConnectionPool(Ice.Logger logger, String url, String username, String password, int numConnections)
throws java.sql.SQLException
{
_logger = logger;
_url = url;
_username = username;
_password = password;
_nconnections = numConnections;
if(_trace)
{
_logger.trace("ConnectionPool", "establishing " + numConnections + " connections to " + url);
}
while(numConnections-- > 0)
{
java.sql.Connection connection = java.sql.DriverManager.getConnection(url, username, password);
connection.setAutoCommit(false);
_connections.add(connection);
}
}
private Ice.Logger _logger;
private boolean _trace = true;
private String _url;
private String _username;
private String _password;
private java.util.LinkedList<java.sql.Connection> _connections = new java.util.LinkedList<java.sql.Connection>();
private boolean _destroyed = false;
private int _nconnections;
}
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