com.northgateis.comms.dda
Class DDATcp

java.lang.Object
 |
 +--com.northgateis.comms.dda.DDATcp

Direct Known Subclasses:

SNI

public class DDATcp

extends java.lang.Object

Defines an object that creates a DDA TCP connection to a Reality database and supplies methods to access this connection.

Typical usage:

 DDATcp con = new DDATcp("host","database","user","account","server");
 con.connect()
 DDAMsg msg = new DDAMsg(1, 0, "Qualifier".getBytes(), "Data".getBytes());
 con.send(msg)		// as required
 msg = con.receive()		// as required
 con.disconnect()	// not essential as destroying the class will disconnect
 

Any DDA or IO exception received during the life of a connection will require a new connect() before any more data can be transfered.

Debugging can be turned on by setting the dda.debug property either on the command line or in the reality.properties file. The property should be set to "on". This will result in all DDA messages sent and received being printed on System.err.

DEFAULT_PORT

public static final int DEFAULT_PORT

The default port used by to connect to a DDA server

DDATcp

public DDATcp(java.lang.String host,
 int port,
 java.lang.String database,
 java.lang.String user,
 java.lang.String account,
 java.lang.String server)

Define a new DDA TCP connection for a non default port.

Parameters:

host - String specifying the host name to connect to.

port - the port number to use.

database - String specifying the database name to connect to.

user - String specifying the user-id used to connect to the database, with an optional comma seperated password

account - String specifying the account used to connect to the database, with an optional comma seperated password

server - String specifying server to run

DDATcp

public DDATcp(java.lang.String host,
 java.lang.String database,
 java.lang.String user,
 java.lang.String account,
 java.lang.String server)

Define a new DDA TCP connection for the default port.

Parameters:

host - String specifying the host name to connect to.

database - String specifying the database name to connect to.

user - String specifying the user-id used to connect to the database, with an optional comma seperated password

account - String specifying the account used to connect to the database, with an optional comma seperated password

server - String specifying server to run

DDATcp

public DDATcp(DDAConnectionSpec spec,
 java.lang.String server)

Define a new DDA TCP connection using a DDAConnectionSpec

Parameters:

spec - DDAConnectionSpec specifying the connection details

server - String specifying server to run

connect

public void connect()
 throws java.io.IOException,
 com.northgateis.comms.dda.DDAException

Connect to the TCP host and the DDA server.

Throws:

java.io.IOException - if an error occurs during the TCP connection

com.northgateis.comms.dda.DDAException - if an error occurs during the DDA negotiation

disconnect

public void disconnect()

Close the TCP connection

send

public void send(DDAMsg msg)
 throws java.io.IOException

Send a DDA message.

Parameters:

msg - the DDAMsg to send.

Throws:

java.io.IOException - if an input or output exception occurs

receive

public DDAMsg receive()
 throws java.io.IOException

Receive a DDA message

Returns:

DDAMsg containing the received data

Throws:

java.io.IOException - if an input or output exception occurs

dataAvailable

public boolean dataAvailable()
 throws java.io.IOException

Test if data available for input

Returns:

true if data available, false otherwise

Throws:

java.io.IOException - if an input or output exception occurs

setTimeout

public void setTimeout(byte Tout)

Set the timeout when making a connection

Parameters:

Tout - the connection timeout in minutes

debug

public static void debug(boolean on)

Turn on/off the debug flag. When debugging is turned on all messages sent and received are dumped to System.err in ASCII hex format.

Parameters:

on - true to turn debugging on, false to turn it off

setServer

public void setServer(java.lang.String server)

Overide the server name used when instantiating the class.

Parameters:

server - Name of the server to use.