org.apache.flink.api.common.operators.util

Class ListKeyGroupedIterator<E>

java.lang.Object

org.apache.flink.api.common.operators.util.ListKeyGroupedIterator<E>

@Internal
public final class ListKeyGroupedIterator<E>
extends Object

The KeyValueIterator returns a key and all values that belong to the key (share the same key).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ListKeyGroupedIterator.ValuesIterator

Constructor Summary

Constructors

Constructor and Description
ListKeyGroupedIterator(List<E> input, TypeSerializer<E> serializer, TypeComparator<E> comparator) Initializes the ListKeyGroupedIterator..

Method Summary

Methods

Modifier and Type	Method and Description
ListKeyGroupedIterator.ValuesIterator	getValues() Returns an iterator over all values that belong to the current key.
boolean	nextKey() Moves the iterator to the next key.

Methods inherited from class java.lang.Object

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

Constructor Detail

ListKeyGroupedIterator

public ListKeyGroupedIterator(List<E> input,
                      TypeSerializer<E> serializer,
                      TypeComparator<E> comparator)

Initializes the ListKeyGroupedIterator..

Parameters:

input - The list with the input elements.

comparator - The comparator for the data type iterated over.

Method Detail

nextKey

public boolean nextKey()
                throws IOException

Moves the iterator to the next key. This method may skip any values that have not yet been returned by the iterator created by the getValues() method. Hence, if called multiple times it "removes" key groups.

Returns:

true, if the input iterator has an other group of records with the same key.

Throws:

IOException

getValues

public ListKeyGroupedIterator.ValuesIterator getValues()

Returns an iterator over all values that belong to the current key. The iterator is initially null (before the first call to nextKey() and after all keys are consumed. In general, this method returns always a non-null value, if a previous call to nextKey() return true.

Returns:

Iterator over all values that belong to the current key.