org.apache.kafka.streams.kstream

Class Materialized<K,V,S extends StateStore>

java.lang.Object

org.apache.kafka.streams.kstream.Materialized<K,V,S>

Type Parameters:

K - type of record key

V - type of record value

S - type of state store (note: state stores always have key/value types <Bytes,byte[]>

public class Materialized<K,V,S extends StateStore>
extends java.lang.Object

Used to describe how a StateStore should be materialized. You can either provide a custom StateStore backend through one of the provided methods accepting a supplier or use the default RocksDB backends by providing just a store name.

For example, you can read a topic as KTable and force a state store materialization to access the content via Interactive Queries API:

 StreamsBuilder builder = new StreamsBuilder();
 KTable<Integer, Integer> table = builder.table(
   "topicName",
   Materialized.as("queryable-store-name"));
 

See Also:

Stores

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	cachingEnabled
protected Serde<K>	keySerde
protected boolean	loggingEnabled
protected java.lang.String	storeName
protected StoreSupplier<S>	storeSupplier
protected java.util.Map<java.lang.String,java.lang.String>	topicConfig
protected Serde<V>	valueSerde

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Materialized(Materialized<K,V,S> materialized) Copy constructor.

Method Summary

Modifier and Type	Method and Description
static <K,V> Materialized<K,V,KeyValueStore<org.apache.kafka.common.utils.Bytes,byte[]>>	as(KeyValueBytesStoreSupplier supplier) Materialize a KeyValueStore using the provided KeyValueBytesStoreSupplier.
static <K,V> Materialized<K,V,SessionStore<org.apache.kafka.common.utils.Bytes,byte[]>>	as(SessionBytesStoreSupplier supplier) Materialize a SessionStore using the provided SessionBytesStoreSupplier.
static <K,V,S extends StateStore> Materialized<K,V,S>	as(java.lang.String storeName) Materialize a StateStore with the given name.
static <K,V> Materialized<K,V,WindowStore<org.apache.kafka.common.utils.Bytes,byte[]>>	as(WindowBytesStoreSupplier supplier) Materialize a WindowStore using the provided WindowBytesStoreSupplier.
static <K,V,S extends StateStore> Materialized<K,V,S>	with(Serde<K> keySerde, Serde<V> valueSerde) Materialize a StateStore with the provided key and value Serdes.
Materialized<K,V,S>	withCachingDisabled() Disable caching for the materialized StateStore.
Materialized<K,V,S>	withCachingEnabled() Enable caching for the materialized StateStore.
Materialized<K,V,S>	withKeySerde(Serde<K> keySerde) Set the keySerde the materialize StateStore will use.
Materialized<K,V,S>	withLoggingDisabled() Disable change logging for the materialized StateStore.
Materialized<K,V,S>	withLoggingEnabled(java.util.Map<java.lang.String,java.lang.String> config) Indicates that a changelog should be created for the store.
Materialized<K,V,S>	withValueSerde(Serde<V> valueSerde) Set the valueSerde the materialized StateStore will use.

Methods inherited from class java.lang.Object

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

Field Detail

storeSupplier

protected StoreSupplier<S extends StateStore> storeSupplier

storeName

protected java.lang.String storeName

valueSerde

protected Serde<V> valueSerde

keySerde

protected Serde<K> keySerde

loggingEnabled

protected boolean loggingEnabled

cachingEnabled

protected boolean cachingEnabled

topicConfig

protected java.util.Map<java.lang.String,java.lang.String> topicConfig

Constructor Detail

Materialized

protected Materialized(Materialized<K,V,S> materialized)

Copy constructor.

Parameters:

materialized - the Materialized instance to copy.

Method Detail

as

public static <K,V,S extends StateStore> Materialized<K,V,S> as(java.lang.String storeName)

Materialize a StateStore with the given name.

Type Parameters:

K - key type of the store

V - value type of the store

S - type of the StateStore

Parameters:

storeName - the name of the underlying KTable state store; valid characters are ASCII alphanumerics, '.', '_' and '-'.

Returns:

a new Materialized instance with the given storeName

as

public static <K,V> Materialized<K,V,WindowStore<org.apache.kafka.common.utils.Bytes,byte[]>> as(WindowBytesStoreSupplier supplier)

Materialize a WindowStore using the provided WindowBytesStoreSupplier.

Type Parameters:

K - key type of the store

V - value type of the store

Parameters:

supplier - the WindowBytesStoreSupplier used to materialize the store

Returns:

a new Materialized instance with the given supplier

as

public static <K,V> Materialized<K,V,SessionStore<org.apache.kafka.common.utils.Bytes,byte[]>> as(SessionBytesStoreSupplier supplier)

Materialize a SessionStore using the provided SessionBytesStoreSupplier.

Type Parameters:

K - key type of the store

V - value type of the store

Parameters:

supplier - the SessionBytesStoreSupplier used to materialize the store

Returns:

a new Materialized instance with the given sup plier

as

public static <K,V> Materialized<K,V,KeyValueStore<org.apache.kafka.common.utils.Bytes,byte[]>> as(KeyValueBytesStoreSupplier supplier)

Materialize a KeyValueStore using the provided KeyValueBytesStoreSupplier.

Type Parameters:

K - key type of the store

V - value type of the store

Parameters:

supplier - the KeyValueBytesStoreSupplier used to materialize the store

Returns:

a new Materialized instance with the given supplier

with

public static <K,V,S extends StateStore> Materialized<K,V,S> with(Serde<K> keySerde,
                                                                  Serde<V> valueSerde)

Materialize a StateStore with the provided key and value Serdes. An internal name will be used for the store.

Type Parameters:

K - key type

V - value type

S - store type

Parameters:

keySerde - the key Serde to use. If the Serde is null, then the default key serde from configs will be used

valueSerde - the value Serde to use. If the Serde is null, then the default value serde from configs will be used

Returns:

a new Materialized instance with the given key and value serdes

withValueSerde

public Materialized<K,V,S> withValueSerde(Serde<V> valueSerde)

Set the valueSerde the materialized StateStore will use.

Parameters:

valueSerde - the value Serde to use. If the Serde is null, then the default value serde from configs will be used

Returns:

itself

withKeySerde

public Materialized<K,V,S> withKeySerde(Serde<K> keySerde)

Set the keySerde the materialize StateStore will use.

Parameters:

keySerde - the key Serde to use. If the Serde is null, then the default key serde from configs will be used

Returns:

itself

withLoggingEnabled

public Materialized<K,V,S> withLoggingEnabled(java.util.Map<java.lang.String,java.lang.String> config)

Indicates that a changelog should be created for the store. The changelog will be created with the provided configs.

Note: Any unrecognized configs will be ignored.

Parameters:

config - any configs that should be applied to the changelog

Returns:

itself

withLoggingDisabled

public Materialized<K,V,S> withLoggingDisabled()

Disable change logging for the materialized StateStore.

Returns:

itself

withCachingEnabled

public Materialized<K,V,S> withCachingEnabled()

Enable caching for the materialized StateStore.

Returns:

itself

withCachingDisabled

public Materialized<K,V,S> withCachingDisabled()

Disable caching for the materialized StateStore.

Returns:

itself