kafka-streams-internals-StreamStreamJoinNode.adoc

StreamStreamJoinNode

StreamStreamJoinNode is a concrete StreamsGraphNode (as a BaseJoinProcessorNode) that is created (using StreamStreamJoinNode.build method) for KStreamImpl.join, KStreamImpl.leftJoin, and KStreamImpl.outerJoin operators.

In other words, StreamStreamJoinNode represents KStreamImpl.join, KStreamImpl.leftJoin, and KStreamImpl.outerJoin operators.

Creating StreamStreamJoinNode Instance

StreamStreamJoinNode takes the following to be created:

• Node name

• ValueJoiner (ValueJoiner<? super V1, ? super V2, ? extends VR>)

• ProcessorParameters<K, V1> of this join side

• ProcessorParameters<K, V2> of the other join side

• ProcessorParameters<K, VR> of the join merger

• ProcessorParameters<K, V1>

• ProcessorParameters<K, V2>

• StoreBuilder of WindowStore (StoreBuilder<WindowStore<K, V1>>)

• StoreBuilder of WindowStore (StoreBuilder<WindowStore<K, V2>>)

• Joined (Joined<K, V1, V2>)

writeToTopology Method

void writeToTopology(
  InternalTopologyBuilder topologyBuilder)

Note	writeToTopology is part of the StreamsGraphNode Contract to…​FIXME.

writeToTopology…​FIXME

Creating StreamStreamJoinNode — build Method

StreamStreamJoinNode<K, V1, V2, VR> build()

build simply creates a new StreamStreamJoinNode.

Note	build is used exclusively when KTableImpl is requested to doJoin (for KTableImpl.join, KTableImpl.leftJoin and KTableImpl.outerJoin operators).