org.apache.kafka.streams.query

Class MultiVersionedKeyQuery<K,V>

java.lang.Object

org.apache.kafka.streams.query.MultiVersionedKeyQuery<K,V>

Type Parameters:

K - The type of the key.

V - The type of the result returned by this query.

All Implemented Interfaces:

Query<VersionedRecordIterator<V>>

@InterfaceStability.Evolving
public final class MultiVersionedKeyQuery<K,V>
extends Object
implements Query<VersionedRecordIterator<V>>

Interactive query for retrieving a set of records with the same specified key and different timestamps within the specified time range. No ordering is guaranteed for the results, but the results can be sorted by timestamp (in ascending or descending order) by calling the corresponding defined methods.

Method Summary

Modifier and Type	Method and Description
Optional<Instant>	fromTime() The starting time point of the query, if specified
MultiVersionedKeyQuery<K,V>	fromTime(Instant fromTime) Specifies the starting time point for the key query.
K	key() The key that was specified for this query.
ResultOrder	resultOrder() The order of the returned records by timestamp.
Optional<Instant>	toTime() The ending time point of the query, if specified
MultiVersionedKeyQuery<K,V>	toTime(Instant toTime) Specifies the ending time point for the key query.
MultiVersionedKeyQuery<K,V>	withAscendingTimestamps() Specifies the order of the returned records by the query as ascending by timestamp.
MultiVersionedKeyQuery<K,V>	withDescendingTimestamps() Specifies the order of the returned records by the query as descending by timestamp.
static <K,V> MultiVersionedKeyQuery<K,V>	withKey(K key) Creates a query that will retrieve the set of records identified by key if any exists (or null otherwise).

Methods inherited from class java.lang.Object

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

Method Detail

withKey

public static <K,V> MultiVersionedKeyQuery<K,V> withKey(K key)

Creates a query that will retrieve the set of records identified by key if any exists (or null otherwise).

While the query by default returns the all the record versions of the specified key, setting the fromTimestamp (by calling the fromTime(Instant) method), and the toTimestamp (by calling the toTime(Instant) method) makes the query to return the record versions associated to the specified time range.

Type Parameters:

K - The type of the key

V - The type of the value that will be retrieved

Parameters:

key - The specified key by the query

Throws:

NullPointerException - if key is null

fromTime

public MultiVersionedKeyQuery<K,V> fromTime(Instant fromTime)

Specifies the starting time point for the key query.

The key query returns all the records that are still existing in the time range starting from the timestamp fromTime. There can be records which have been inserted before the fromTime and are still valid in the query specified time range (the whole time range or even partially). The key query in fact returns all the records that have NOT become tombstone at or after fromTime.

Parameters:

fromTime - The starting time point If fromTime is null, it will be considered as negative infinity, ie, no lower bound

toTime

public MultiVersionedKeyQuery<K,V> toTime(Instant toTime)

Specifies the ending time point for the key query. The key query returns all the records that have timestamp <= toTime.

Parameters:

toTime - The ending time point If @param toTime is null, will be considered as positive infinity, ie, no upper bound

withDescendingTimestamps

public MultiVersionedKeyQuery<K,V> withDescendingTimestamps()

Specifies the order of the returned records by the query as descending by timestamp.

withAscendingTimestamps

public MultiVersionedKeyQuery<K,V> withAscendingTimestamps()

Specifies the order of the returned records by the query as ascending by timestamp.

key

public K key()

The key that was specified for this query.

Returns:

The specified key of the query.

fromTime

public Optional<Instant> fromTime()

The starting time point of the query, if specified

Returns:

The specified fromTime of the query.

toTime

public Optional<Instant> toTime()

The ending time point of the query, if specified

Returns:

The specified toTime of the query.

resultOrder

public ResultOrder resultOrder()

The order of the returned records by timestamp.

Returns:

the order of returned records based on timestamp (can be unordered, or in ascending, or in descending order of timestamps).