com.hazelcast.mapreduce.aggregation.impl

Class KeyPredicateSupplier<KeyIn,ValueIn,ValueOut>

java.lang.Object

com.hazelcast.mapreduce.aggregation.Supplier<KeyIn,ValueIn,ValueOut>

com.hazelcast.mapreduce.aggregation.impl.KeyPredicateSupplier<KeyIn,ValueIn,ValueOut>

Type Parameters:

KeyIn - the input key type

ValueIn - the input value type

ValueOut - the output value type

All Implemented Interfaces:

DataSerializable, IdentifiedDataSerializable, Serializable

public class KeyPredicateSupplier<KeyIn,ValueIn,ValueOut>
extends Supplier<KeyIn,ValueIn,ValueOut>
implements IdentifiedDataSerializable

The default supplier for KeyPredicates, used to filter and optionally transform data (using the given Supplier).

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
KeyPredicateSupplier(KeyPredicate<KeyIn> keyPredicate)
KeyPredicateSupplier(KeyPredicate<KeyIn> keyPredicate, Supplier<KeyIn,ValueIn,ValueOut> chainedSupplier)

Method Summary

Modifier and Type	Method and Description
ValueOut	apply(Map.Entry<KeyIn,ValueIn> entry) The apply method is used to apply the actual filtering or extraction / transformation to the input entry. If the input value should be ignored by the aggregation, the Supplier has to return
int	getFactoryId() Returns DataSerializableFactory factory ID for this class.
int	getId() Returns type identifier for this class.
void	readData(ObjectDataInput in) Reads fields from the input stream
void	writeData(ObjectDataOutput out) Writes object fields to output stream

Methods inherited from class com.hazelcast.mapreduce.aggregation.Supplier

all, all, fromKeyPredicate, fromKeyPredicate, fromPredicate, fromPredicate

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyPredicateSupplier

public KeyPredicateSupplier(KeyPredicate<KeyIn> keyPredicate)

KeyPredicateSupplier

public KeyPredicateSupplier(KeyPredicate<KeyIn> keyPredicate,
                            Supplier<KeyIn,ValueIn,ValueOut> chainedSupplier)

Method Detail

apply

public ValueOut apply(Map.Entry<KeyIn,ValueIn> entry)

Description copied from class: Supplier

The apply method is used to apply the actual filtering or extraction / transformation to the input entry.
If the input value should be ignored by the aggregation, the Supplier has to return

null

as the supplied value, therefor

null

is not a legal value itself!
All custom suppliers have to be serializable: if they hold internal state, remember that the same supplier instance might be used from multiple threads concurrently.

Specified by:

apply in class Supplier<KeyIn,ValueIn,ValueOut>

Parameters:

entry - the entry key-value pair to supply to the aggregation

Returns:

the supplied value or null if value should be ignored

getFactoryId

public int getFactoryId()

Description copied from interface: IdentifiedDataSerializable

Returns DataSerializableFactory factory ID for this class.

Specified by:

getFactoryId in interface IdentifiedDataSerializable

Returns:

factory ID

getId

public int getId()

Description copied from interface: IdentifiedDataSerializable

Returns type identifier for this class. It should be unique per DataSerializableFactory.

Specified by:

getId in interface IdentifiedDataSerializable

Returns:

type ID

writeData

public void writeData(ObjectDataOutput out)
               throws IOException

Description copied from interface: DataSerializable

Writes object fields to output stream

Specified by:

writeData in interface DataSerializable

Parameters:

out - output

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

readData

public void readData(ObjectDataInput in)
              throws IOException

Description copied from interface: DataSerializable

Reads fields from the input stream

Specified by:

readData in interface DataSerializable

Parameters:

in - input

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the input stream has been closed.