org.jcsp.lang
Class AltingConnectionServerImpl

java.lang.Object
  org.jcsp.lang.Guard
      org.jcsp.lang.AltingConnectionServer
          org.jcsp.lang.AltingConnectionServerImpl

All Implemented Interfaces:

ConnectionServer

public class AltingConnectionServerImpl
extends AltingConnectionServer

This class does not need to be used by standard JCSP users. It is exposed so that the connection mechanism can be extended for custom connections.

Author:

Quickstone Technologies Limited

Field Summary

protected static int	SERVER_STATE_CLOSED Server state.
protected static int	SERVER_STATE_OPEN Server state.
protected static int	SERVER_STATE_RECEIVED Server state.

Fields inherited from interface org.jcsp.lang.ConnectionServer

FACTORY

Constructor Summary

protected

AltingConnectionServerImpl(AltingChannelInput openIn, AltingChannelInput furtherRequestIn) Constructs a new server instance.

Method Summary

protected int	getServerState()
void	reply(Object data) Sends some data back to the client after a request has been received but keeps the connection open.
void	reply(Object data, boolean close) Sends some data back to the client after a request has been received.
void	replyAndClose(Object data) Sends some data back to the client and closes the connection.
Object	request() Receives some data from a client once a connection has been established.

Methods inherited from class org.jcsp.lang.AltingConnectionServer

getAltingChannel, pending, setAltingChannel

Methods inherited from class org.jcsp.lang.Guard

schedule

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SERVER_STATE_CLOSED

protected static final int SERVER_STATE_CLOSED

Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:

Constant Field Values

SERVER_STATE_OPEN

protected static final int SERVER_STATE_OPEN

Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:

Constant Field Values

SERVER_STATE_RECEIVED

protected static final int SERVER_STATE_RECEIVED

Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:

Constant Field Values

Constructor Detail

AltingConnectionServerImpl

protected AltingConnectionServerImpl(AltingChannelInput openIn,
                                     AltingChannelInput furtherRequestIn)

Constructs a new server instance. This must be called by a subclass which is responsible for creating the channels.

Method Detail

request

public Object request()
               throws IllegalStateException

Receives some data from a client once a connection has been established. This will block until the client calls request(Object) but by establishing a connection.

Returns:

the Object sent by the client.

Throws:

IllegalStateException

reply

public void reply(Object data)
           throws IllegalStateException

Sends some data back to the client after a request has been received but keeps the connection open. After calling this method, the server should call recieve() to receive a further request.

Parameters:

data - the data to send to the client.

Throws:

IllegalStateException

reply

public void reply(Object data,
                  boolean close)
           throws IllegalStateException

Sends some data back to the client after a request has been received. The closed parameter indicates whether or not the connection should be closed. The connection will be closed iff close is true.

Parameters:

data - the data to send to the client.

close - boolean indicating whether or not the connection should be closed.

Throws:

IllegalStateException

replyAndClose

public void replyAndClose(Object data)
                   throws IllegalStateException

Sends some data back to the client and closes the connection. This method will not block. After calling this method, the server may call accept() in order to allow another connection to this server to be established. If this method did not take any data to send back to the client, and the server was meant to call reply(Object) followed by a close(), then there would be a race hazard at the client as it would not know whether the connection had remained open or not.

Parameters:

data - the data to send back to client.

Throws:

IllegalStateException

getServerState

protected int getServerState()