com.antelmann.util
Class IteratorQueue<T>

java.lang.Object
  com.antelmann.util.IteratorQueue<T>

All Implemented Interfaces:

ValueRetriever<T>, Wrapped<Queue<T>>, Closeable, Iterable<T>, Enumeration<T>, Iterator<T>

public class IteratorQueue<T>
extends Object
implements Iterator<T>, Closeable, ValueRetriever<T>, Wrapped<Queue<T>>, Iterable<T>, Enumeration<T>

a special iterator that supplies elements from an embedded blocking queue and blocks on calls to hasNext(). This class is particularly handy if you want to supply data through an iterator from a different thread than from where it is read. The next() method only returns false after the close() method is called and the queue is empty.

Since:

20.05.2009, 13:50:08

Author:

Holger Antelmann

Constructor Summary

IteratorQueue(Collection<? extends T> collection)

IteratorQueue(T... elements)

Method Summary

void	add(T element)
int	available() a non-blocking call to see how many elements are currently available in this queue
void	clearException()
void	close()
int	getCounter()
Throwable	getException()
T	getRelevantValue() returns the relevant value for this instance at the time of calling
boolean	hasMoreElements()
boolean	hasNext()
boolean	isClosed()
Iterator<T>	iterator()
T	next()
T	nextElement()
void	remove()
void	setException(String msg) throws an exception to the caller of hasNext()
void	setException(Throwable exception) throws an exception to the caller of hasNext()
Queue<T>	unwrap() returns the embedded instance that this wrapper encloses

Methods inherited from class java.lang.Object

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

Constructor Detail

IteratorQueue

public IteratorQueue(T... elements)

IteratorQueue

public IteratorQueue(Collection<? extends T> collection)

Method Detail

unwrap

public Queue<T> unwrap()

Description copied from interface: Wrapped

returns the embedded instance that this wrapper encloses

Specified by:

unwrap in interface Wrapped<Queue<T>>

add

public void add(T element)
         throws IllegalStateException

Throws:

IllegalStateException

setException

public void setException(String msg)

throws an exception to the caller of hasNext()

setException

public void setException(Throwable exception)

throws an exception to the caller of hasNext()

getException

public Throwable getException()

clearException

public void clearException()

available

public int available()

a non-blocking call to see how many elements are currently available in this queue

getCounter

public int getCounter()

getRelevantValue

public T getRelevantValue()
                   throws IOException

Description copied from interface: ValueRetriever

returns the relevant value for this instance at the time of calling

Specified by:

getRelevantValue in interface ValueRetriever<T>

Throws:

IOException - if any resource to fulfill the request is not accessible

hasNext

public boolean hasNext()
                throws IterationException

Specified by:

hasNext in interface Iterator<T>

Throws:

IterationException

next

public T next()

Specified by:

next in interface Iterator<T>

remove

public void remove()

Specified by:

remove in interface Iterator<T>

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>

hasMoreElements

public boolean hasMoreElements()

Specified by:

hasMoreElements in interface Enumeration<T>

nextElement

public T nextElement()

Specified by:

nextElement in interface Enumeration<T>

isClosed

public boolean isClosed()

close

public void close()

Specified by:

close in interface Closeable