org.apache.flink.api.common.typeutils

Class TypePairComparator<T1,T2>

java.lang.Object

org.apache.flink.api.common.typeutils.TypePairComparator<T1,T2>

Type Parameters:

T1 - The class of the first data type.

T2 - The class of the second data type.

Direct Known Subclasses:

GenericPairComparator, SameTypePairComparator

@Internal
public abstract class TypePairComparator<T1,T2>
extends Object

This interface defines the method required by the runtime to use data types in join-like operations. In such operations, instances of different data types are compared for equality with respect to certain attributes, such as join keys.

The class compares instances of two different data types. One is always used as the reference data type, and the other is checked against the reference. An instance of the reference data type is normally set as the reference for comparisons. Afterwards one or more instances of the other data type are checked against the reference.

Constructor Summary

Constructors

Constructor and Description
TypePairComparator()

Method Summary

Modifier and Type	Method and Description
abstract int	compareToReference(T2 candidate)
abstract boolean	equalToReference(T2 candidate) Checks, whether the given candidate instance is equal to the reference instance, with respect to this comparator's equality definition.
abstract void	setReference(T1 reference) Sets the reference for comparisons.

Methods inherited from class java.lang.Object

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

Constructor Detail

TypePairComparator

public TypePairComparator()

Method Detail

setReference

public abstract void setReference(T1 reference)

Sets the reference for comparisons.

Parameters:

reference - The reference instance.

equalToReference

public abstract boolean equalToReference(T2 candidate)

Checks, whether the given candidate instance is equal to the reference instance, with respect to this comparator's equality definition.

Parameters:

candidate - The candidate to check.

Returns:

True, if the candidate is equal to the reference, false otherwise.

compareToReference

public abstract int compareToReference(T2 candidate)