org.entityfs.util.itr
Class AbstractIterator<T extends org.entityfs.util.itr.IteratorContext<U>,U>

java.lang.Object
  org.entityfs.util.itr.AbstractIterator<T,U>

All Implemented Interfaces:

Iterator<U>

Direct Known Subclasses:

DepthFirstIteratorImpl, DepthLastIteratorImpl, LocationAwareDepthFirstIteratorImpl, LocationAwareDepthLastIteratorImpl

public abstract class AbstractIterator<T extends org.entityfs.util.itr.IteratorContext<U>,U>
extends Object
implements Iterator<U>

This is an abstract class that can be inherited by EntityView iterator implementations. It implements a recursive iterator that can be configured to do the following things:

• Recurse directories depth first or depth last.
• Sort the entities returned from a directory. The entities are either sorted in their natural order (see Entity), or using a supplied Comparator.
• Return the root entity or not.
• Filter the returned entities, just like FilteringIterator.

Subclasses implement the createChildIteratorContext(Object, IteratorContext) to create child directory iterators.

EntityFS iterators are not thread safe. Don't use them concurrently from several threads without synchronizing access to them.

Since:

1.0

Author:

Karl Gustafsson

Constructor Summary

protected

AbstractIterator(Filter<? super EntityView> f, T firstOnStack)

Method Summary

protected abstract T	createChildIteratorContext(U dv, T parentContext)
protected LinkedList<T>	getContextStack()
protected Filter<? super EntityView>	getFilter()
boolean	hasNext()
U	next()
void	remove()
protected void	setNext(U ev)
protected abstract boolean	testAndSetNext()
protected boolean	testAndSetNextChildEntity(T curContext)
protected boolean	testAndSetNextSubdirectory(T curContext)

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractIterator

protected AbstractIterator(Filter<? super EntityView> f,
                           T firstOnStack)

Method Detail

getContextStack

protected LinkedList<T> getContextStack()

getFilter

protected Filter<? super EntityView> getFilter()

setNext

protected void setNext(U ev)

createChildIteratorContext

protected abstract T createChildIteratorContext(U dv,
                                                T parentContext)

testAndSetNextSubdirectory

protected boolean testAndSetNextSubdirectory(T curContext)

testAndSetNextChildEntity

protected boolean testAndSetNextChildEntity(T curContext)

testAndSetNext

protected abstract boolean testAndSetNext()

next

public U next()

Specified by:

next in interface Iterator<U>

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<U>

remove

public void remove()
            throws UnsupportedOperationException

Specified by:

remove in interface Iterator<U>

Throws:

UnsupportedOperationException - Always.