wt.util
Class Consumer

java.lang.Object
  wt.util.Consumer

All Implemented Interfaces:

Iterator

Direct Known Subclasses:

FileConsumer

public abstract class Consumer

extends Object

implements Iterator

Provides support for a multi-threaded producer/consumer. Subclasses should call the init() method before using the consumer.

Supported API: false
Extendable: false

Nested Class Summary

protected static interface	Consumer.Producer A utility interface that the Consumer uses to producer data.
protected static interface	Consumer.Queue Utility interface that the Consumer uses to buffer data.
protected static class	Consumer.SynchronizedQueue Provides basic synchronization for a multi-threaded producer/consumer situation.

Field Summary

protected static int	DEFAULT_BUFFER_SIZE
protected Consumer.Producer	producer
protected Consumer.Queue	queue

Constructor Summary

Consumer()

Method Summary

protected Consumer.Queue	createQueue(int max_buffer_size) Hook to let subclasses create a different queue.
void	finalize() This method should be called if you would like to stop iterating prematurely, to allow cleanup work to be done.
boolean	hasNext()
protected void	init(Consumer.Producer p)
protected void	init(Consumer.Producer p, Consumer.Queue q)
protected void	init(Consumer.Producer p, int max_buffer_size)
Object	next()
void	remove() Throws an UnsupportedOperationException.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_BUFFER_SIZE

protected static final int DEFAULT_BUFFER_SIZE

See Also:

Constant Field Values

producer

protected Consumer.Producer producer

queue

protected Consumer.Queue queue

Constructor Detail

Consumer

public Consumer()

Method Detail

init

protected final void init(Consumer.Producer p,
                          Consumer.Queue q)

Parameters:

p - The producer that will load the data.

q - The queue to get data from.

init

protected final void init(Consumer.Producer p,
                          int max_buffer_size)

Parameters:

p - The producer that will load the data.

max_buffer_size - The number of lines that should be buffered internally by the consumer.

init

protected final void init(Consumer.Producer p)

Parameters:

p - The producer that will load the data.

createQueue

protected Consumer.Queue createQueue(int max_buffer_size)

Hook to let subclasses create a different queue.

Parameters:

max_buffer_size - The maximum size the queue can attain.

hasNext

public final boolean hasNext()

Specified by:

hasNext in interface Iterator

Returns:

true if queue.hasNext() is true.

next

public final Object next()

Specified by:

next in interface Iterator

Returns:

the next entry in the queue.

remove

public final void remove()

Throws an UnsupportedOperationException.

Specified by:

remove in interface Iterator

finalize

public void finalize()

This method should be called if you would like to stop iterating prematurely, to allow cleanup work to be done.