static string GetMSSqlPort(string instanceName, string dataSource, int timeout)
{
string port = String.Empty;
try {
DatagramSocket socket = new DatagramSocket();
// send request
sbyte[] buf = new sbyte[] { 2 };
InetAddress address = InetAddress.getByName(dataSource);
DatagramPacket packet = new DatagramPacket(buf, buf.Length, address, 1434);
socket.send(packet);
sbyte[] recbuf = new sbyte[1024];
packet = new DatagramPacket(recbuf, recbuf.Length, packet.getAddress(), packet.getPort());
// try to receive from socket while increasing timeouts in geometric progression
int iterationTimeout = 1;
int totalTimeout = 0;
for (;;)
{
socket.setSoTimeout(iterationTimeout);
try {
socket.receive(packet);
break;
}
catch (SocketTimeoutException e) {
totalTimeout += iterationTimeout;
iterationTimeout *= 2;
if (totalTimeout >= timeout * 1000)
{
throw new java.sql.SQLException(
String.Format("Unable to retrieve the port number for {0} using UDP on port 1434. Please see your network administrator to solve this problem or add the port number of your SQL server instance to your connection string (i.e. port=1433).", dataSource)
);
}
}
}
sbyte[] rcvdSbytes = packet.getData();
char[] rcvdChars = new char[rcvdSbytes.Length];
for (int i = 0; i < rcvdSbytes.Length; i++)
{
rcvdChars[i] = (char)rcvdSbytes[i];
}
String received = new String(rcvdChars);
java.util.StringTokenizer st = new java.util.StringTokenizer(received, ";");
String prev = "";
bool instanceReached = instanceName == null || instanceName.Length == 0;
while (st.hasMoreTokens())
{
if (!instanceReached)
{
if (prev.Trim().Equals("InstanceName"))
{
if (String.Compare(instanceName, st.nextToken().Trim(), true, CultureInfo.InvariantCulture) == 0)
{
instanceReached = true;
}
}
}
else
{
if (prev.Trim().Equals("tcp"))
{
port = st.nextToken().Trim();
//ensure we got a valid int
java.lang.Integer.parseInt(port);
break;
}
}
prev = st.nextToken();
}
socket.close();
if (!instanceReached)
{
throw new java.sql.SQLException(
String.Format("Specified SQL Server '{0}\\{1}' not found.", dataSource, instanceName)
);
}
return(port);
}
catch (java.sql.SQLException) {
throw;
}
catch (Exception e) {
throw new java.sql.SQLException(e.Message);
}
}