org.umber.catalan.queues
Class StreamQueue

java.lang.Object
  org.umber.catalan.queues.StreamQueue

All Implemented Interfaces:

ICommandQueue

public abstract class StreamQueue

extends java.lang.Object

implements ICommandQueue

Queue which loads commands from a single InputStream and writes the processed results to a single OutputStream.

Author:

jsheets

Constructor Summary

StreamQueue(java.io.InputStream input, java.io.OutputStream output)
Creates a new instance of DirectoryPollQueue.

Method Summary

protected abstract IForgeCommand	buildCommand(java.io.InputStream input) Loads a IForgeCommand object from the InputStream.
boolean	canQuit() Determines if the queue can safely disconnect without losing its current status.
void	connect() Establishes a connection to the queue.
void	disconnect() Closes down the queue.
protected java.io.InputStream	getInput() Retrieves the input stream.
IForgeCommand	getNextCommand() Retrieves the next command in the queue, or null if queue is empty.
protected java.io.OutputStream	getOutput() Retrieves the output stream.
boolean	isConnected() Determines if the queue is currently connected to a live command feed.
void	sendResult(CommandResult result)

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamQueue

public StreamQueue(java.io.InputStream input,
                   java.io.OutputStream output)

Creates a new instance of DirectoryPollQueue.

Parameters:

input - stream to pull command files from

output - stream to write completed command files to

Method Detail

buildCommand

protected abstract IForgeCommand buildCommand(java.io.InputStream input)
                                       throws CatalanCommandException

Loads a IForgeCommand object from the InputStream.

Parameters:

input - raw data stream of command data

Returns:

a command object from the InputStream

Throws:

CatalanCommandException - if unable to load or convert the command data

getInput

protected java.io.InputStream getInput()

Retrieves the input stream.

Returns:

input stream

getOutput

protected java.io.OutputStream getOutput()

Retrieves the output stream.

Returns:

output stream

isConnected

public boolean isConnected()

Determines if the queue is currently connected to a live command feed.

Specified by:

isConnected in interface ICommandQueue

Returns:

true if connected

connect

public void connect()
             throws CatalanQueueException

Establishes a connection to the queue.

This implementation checks for valid input and output streams.

Specified by:

connect in interface ICommandQueue

Throws:

CatalanQueueException - if unable to fully access input and output streams

disconnect

public void disconnect()
                throws CatalanQueueException

Closes down the queue.

This implementation closes the input and output streams.

Specified by:

disconnect in interface ICommandQueue

Throws:

CatalanQueueException - if unable to close streams.

canQuit

public boolean canQuit()

Determines if the queue can safely disconnect without losing its current status. This should only be called between commands.

This implementation always returns true.

Specified by:

canQuit in interface ICommandQueue

Returns:

always true

getNextCommand

public IForgeCommand getNextCommand()
                             throws CatalanQueueException,
                                    CatalanCommandException

Retrieves the next command in the queue, or null if queue is empty.

This implementation reads the next command from the InputStream.

Specified by:

getNextCommand in interface ICommandQueue

Returns:

processing command, or null if queue is empty

Throws:

CatalanQueueException - if the input stream is not readable

CatalanCommandException - if unable to process the command data

sendResult

public void sendResult(CommandResult result)
                throws CatalanQueueException

Specified by:

sendResult in interface ICommandQueue

Throws:

CatalanQueueException