Package com.hazelcast.projection

Class Projections

java.lang.Object

com.hazelcast.projection.Projections

public final class Projections
extends Object

A utility class to create basic Projection instances.

Since:

3.8

Method Summary

Modifier and Type	Method	Description
static <T> Projection<T,T>	identity()	Returns a projection that does no transformation.
static <I> Projection<I,Object[]>	multiAttribute(String... attributePaths)	Returns a projection that extracts the value of the given attributePaths.
static <I, O> Projection<I,O>	singleAttribute(String attributePath)	Returns a projection that extracts the value of the given attributePath.

Methods inherited from class java.lang.Object

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

Method Details

identity

public static <T> Projection<T,T> identity()

Returns a projection that does no transformation.

If you use the returned projection in a 3.9 cluster it may cause a serialization exception.

Type Parameters:

T - type

Since:

3.10

singleAttribute

public static <I,
O> Projection<I,O> singleAttribute(String attributePath)

Returns a projection that extracts the value of the given attributePath.

Type Parameters:

I - input type

O - output type

Parameters:

attributePath - single attribute path, path must not be null or empty

multiAttribute

public static <I> Projection<I,Object[]> multiAttribute(String... attributePaths)

Returns a projection that extracts the value of the given attributePaths. The attribute values will be returned as an Object[] array from each projection call.

Type Parameters:

I - input type

Parameters:

attributePaths - attribute paths, paths must not be null or empty