com.stephengware.java.mss

Class EventQueue

java.lang.Object

com.stephengware.java.mss.EventQueue

public class EventQueue
extends java.lang.Object

An EventQueue listens for incoming Connections and allows the user to get a sequence of Events via the pop method.

The sequence of events is guaranteed to have the following properties:

• The Event.SERVER_START_EVENT will always be first (unless the server failed to start).
• Exactly one ConnectEvent will occur per connection.
• Exactly one DisconnectEvent will occur per connection. There will always be a DisconnectEvent for every connection, even if the event queue is stopped while the connection is active.
• Zero to many InputEvents will occur per connection. InputEvents will always come after the connection's ConnectEvent and before the connection's {DisconnectEvent}.
• The Event.SERVER_STOP_EVENT will always be last (unless the server failed to start).
• ExceptionEvents can occur at any time. If the server fails to start, an ExceptionEvent will explain why.

The EventQueue does not begin listening for connections until the start method is called. When the stop method is called, all active connections will be closed and any new connections will be refused. The pop method will continue to return events until all the requirements above are met.

Calls to pop before the queue is started or after the queue has returned the Event.SERVER_STOP_EVENT will return null.

An EventQueue can only be started once.

The EventQueue creates new Connection objects for each new socket that connects. If you want to extend Connection, override the protected createNewConnection method.

Version:

1

Author:

Stephen G. Ware

Field Summary

Fields

Modifier and Type	Field and Description
int	port The port on which the event queue will listen for connections.

Constructor Summary

Constructors

Constructor and Description
EventQueue(int port) Creates a new EventQueue which, when started, will listen on the given port for new Connections and begin filling with Events.

Method Summary

Methods

Modifier and Type	Method and Description
protected Connection	createNewConnection(java.net.Socket socket) This method creates a new Connection object for each socket that connects.
Event	pop() Removes the first Event from the queue and returns it.
void	start() When this method is called, the EventQueue begins listening on the specified port for new connections and begins filling with events.
void	stop() When this method is called, the EventQueue will stop listening for new connections and close all currently active connections.

Methods inherited from class java.lang.Object

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

Field Detail

port

public final int port

The port on which the event queue will listen for connections.

Constructor Detail

EventQueue

public EventQueue(int port)

Creates a new EventQueue which, when started, will listen on the given port for new Connections and begin filling with Events.

Parameters:

port - the port to listen on

Method Detail

createNewConnection

protected Connection createNewConnection(java.net.Socket socket)
                                  throws java.io.IOException

This method creates a new Connection object for each socket that connects. If you want to extend Connection, override this method to return objects which are a subclass of Connection.

Parameters:

socket - the newly connected socket

Returns:

a Connection object for that socket

Throws:

java.io.IOException - if an I/O error occurs while creating the Connection

start

public final void start()

When this method is called, the EventQueue begins listening on the specified port for new connections and begins filling with events.

pop

public final Event pop()

Removes the first Event from the queue and returns it. If the queue is empty, this method will block until an event is added.

Returns:

the first Event in the queue

stop

public final void stop()

When this method is called, the EventQueue will stop listening for new connections and close all currently active connections. The pop method will continue to return events after this method is called until the queue is empty.