com.google.cloud.dataflow.sdk.util

Class NullSideInputReader

java.lang.Object

com.google.cloud.dataflow.sdk.util.NullSideInputReader

All Implemented Interfaces:

SideInputReader

public class NullSideInputReader
extends Object
implements SideInputReader

A SideInputReader representing a well-defined set of views, but not storing any values for them. Used to check if a side input is present when the data itself comes from elsewhere.

Method Summary

Modifier and Type	Method and Description
<T> boolean	contains(PCollectionView<T> view) Returns true if the given PCollectionView is valid for this reader.
static NullSideInputReader	empty()
<T> T	get(PCollectionView<T> view, BoundedWindow window) Returns the value of the given PCollectionView for the given BoundedWindow.
boolean	isEmpty() Returns true if there are no side inputs in this reader.
static NullSideInputReader	of(Iterable<? extends PCollectionView<?>> views)

Methods inherited from class java.lang.Object

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

Method Detail

empty

public static NullSideInputReader empty()

of

public static NullSideInputReader of(Iterable<? extends PCollectionView<?>> views)

get

public <T> T get(PCollectionView<T> view,
                 BoundedWindow window)

Description copied from interface: SideInputReader

Returns the value of the given PCollectionView for the given BoundedWindow.

It is valid for a side input to be null. It is not valid for this to return null for any other reason.

Specified by:

get in interface SideInputReader

isEmpty

public boolean isEmpty()

Description copied from interface: SideInputReader

Returns true if there are no side inputs in this reader.

Specified by:

isEmpty in interface SideInputReader

contains

public <T> boolean contains(PCollectionView<T> view)

Description copied from interface: SideInputReader

Returns true if the given PCollectionView is valid for this reader.

Specified by:

contains in interface SideInputReader