de.ipcon.schema.tools

Class CollectingIterator<V extends Identifiable>

java.lang.Object

de.ipcon.schema.tools.CollectingIterator<V>

Type Parameters:

V - the type of elements returned by this iterator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.util.Iterator<V>

public class CollectingIterator<V extends Identifiable>
extends java.lang.Object
implements java.util.Iterator<V>, java.io.Closeable

An iterator that caches already fetched elements while iterating.

Constructor Summary

Constructors

Constructor and Description
CollectingIterator(java.util.Iterator<V> sourceIterator, java.util.Map<java.lang.Long,V> cache) Creates a new CollectingIterator object with the specified iterator and caching map.

Method Summary

Modifier and Type	Method and Description
void	close()
java.util.Map<java.lang.Long,V>	getCollectedValues() Returns an unmodifiable map containing all the cached values.
boolean	hasNext() Returns true if the source iterator has more elements to fetch.
V	next() Returns the next element in the iteration and caches it in the map.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Detail

CollectingIterator

public CollectingIterator(java.util.Iterator<V> sourceIterator,
                          java.util.Map<java.lang.Long,V> cache)

Creates a new CollectingIterator object with the specified iterator and caching map.

Parameters:

sourceIterator - the iterator for iterating over the elements.

cache - the map to cache the already fetched elements.

Method Detail

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

hasNext

public boolean hasNext()

Returns true if the source iterator has more elements to fetch.

Specified by:

hasNext in interface java.util.Iterator<V extends Identifiable>

Returns:

true if the source iterator has more elements

next

public V next()

Returns the next element in the iteration and caches it in the map.

Specified by:

next in interface java.util.Iterator<V extends Identifiable>

Returns:

the next element in the iteration.

getCollectedValues

public java.util.Map<java.lang.Long,V> getCollectedValues()

Returns an unmodifiable map containing all the cached values.

Returns:

an unmodifiable map of cached values

Throws:

java.lang.IllegalStateException - if not all values have been collected yet