Interface ValueMapperWithKey<K,V,VR>

Type Parameters:

K - key type

V - value type

VR - mapped value type

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ValueMapperWithKey<K,V,VR>

The ValueMapperWithKey interface for mapping a value to a new value of arbitrary type. This is a stateless record-by-record operation, i.e, apply(Object, Object) is invoked individually for each record of a stream (cf. FixedKeyProcessor for stateful value transformation). If ValueMapperWithKey is applied to a Record the record's key is preserved. Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. If a record's key and value should be modified KeyValueMapper can be used.

See Also:

• KeyValueMapper
• FixedKeyProcessor
• KStream.mapValues(ValueMapper)
• KStream.mapValues(ValueMapperWithKey)
• KStream.flatMapValues(ValueMapper)
• KStream.flatMapValues(ValueMapperWithKey)
• KTable.mapValues(ValueMapper)
• KTable.mapValues(ValueMapperWithKey)

Method Summary

Modifier and Type	Method	Description
VR	apply(K readOnlyKey, V value)	Map the given [key and ]value to a new value.

Method Details

apply

VR apply(K readOnlyKey,
 V value)

Map the given [key and ]value to a new value.

Parameters:

readOnlyKey - the read-only key

value - the value to be mapped

Returns:

the new value