ListKeyGroupedIterator (Flink : Core 1.18.1-cp1 API)

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 Description

class ListKeyGroupedIterator.ValuesIterator

Constructor Summary

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

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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.