K- key type
V- value type
VR- mapped value type
public interface ValueMapperWithKey<K,V,VR>
ValueMapperWithKeyinterface 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.
ValueTransformerfor stateful value transformation). If
ValueMapperWithKeyis applied to a
key-value pairrecord 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
KeyValueMappercan be used.