io.delta.kernel.utils

Interface CloseableIterator<T>

Type Parameters:

T - the type of elements returned by this iterator

All Superinterfaces:

AutoCloseable, java.io.Closeable, java.util.Iterator<T>

All Known Implementing Classes:

ActionsIterator, ActiveAddFilesIterator, CreateCheckpointIterator

@Evolving
public interface CloseableIterator<T>
extends java.util.Iterator<T>, java.io.Closeable

Closeable extension of Iterator

Since:

3.0.0

Method Summary

Modifier and Type	Method and Description
default CloseableIterator<T>	combine(CloseableIterator<T> other) Combine the current iterator with another iterator.
default CloseableIterator<T>	filter(java.util.function.Function<T,Boolean> mapper)
boolean	hasNext() Returns true if the iteration has more elements.
default <U> CloseableIterator<U>	map(java.util.function.Function<T,U> mapper)
T	next() Returns the next element in the iteration.

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Methods inherited from interface java.io.Closeable

close

Method Detail

hasNext

boolean hasNext()

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Specified by:

hasNext in interface java.util.Iterator<T>

Returns:

true if the iteration has more elements

Throws:

KernelEngineException - For any underlying exception occurs in Engine while trying to execute the operation. The original exception is (if any) wrapped in this exception as cause. E.g. IOException thrown while trying to read from a Delta log file. It will be wrapped in this exception as cause.

KernelException - When encountered an operation or state that is invalid or unsupported.

next

T next()

Returns the next element in the iteration.

Specified by:

next in interface java.util.Iterator<T>

Returns:

the next element in the iteration

Throws:

java.util.NoSuchElementException - if the iteration has no more elements

KernelEngineException - For any underlying exception occurs in Engine while trying to execute the operation. The original exception is (if any) wrapped in this exception as cause. E.g. IOException thrown while trying to read from a Delta log file. It will be wrapped in this exception as cause.

KernelException - When encountered an operation or state that is invalid or unsupported in Kernel. For example, trying to read from a Delta table that has advanced features which are not yet supported by Kernel.

map

default <U> CloseableIterator<U> map(java.util.function.Function<T,U> mapper)

filter

default CloseableIterator<T> filter(java.util.function.Function<T,Boolean> mapper)

combine

default CloseableIterator<T> combine(CloseableIterator<T> other)

Combine the current iterator with another iterator. The resulting iterator will return all elements from the current iterator followed by all elements from the other iterator.

Parameters:

other - the other iterator to combine with

Returns:

a new iterator that combines the current iterator with the other iterator