| Interface | Description | 
|---|---|
| BatchingStateRestoreCallback | 
 Interface for batching restoration of a  
StateStore
 It is expected that implementations of this class will not call the StateRestoreCallback.restore(byte[],
 byte[]) method. | 
| Cancellable | 
 Cancellable interface returned in  
ProcessorContext.schedule(long, PunctuationType, Punctuator). | 
| PartitionGrouper | 
 A partition grouper that generates partition groups given the list of topic-partitions. 
 | 
| Processor<K,V> | 
 A processor of key-value pair records. 
 | 
| ProcessorContext | 
 Processor context interface. 
 | 
| ProcessorSupplier<K,V> | 
 A processor supplier that can create one or more  
Processor instances. | 
| Punctuator | 
 A functional interface used as an argument to  
ProcessorContext.schedule(long, PunctuationType, Punctuator). | 
| RecordContext | 
 The context associated with the current record being processed by
 an  
Processor | 
| StateRestoreCallback | 
 Restoration logic for log-backed state stores upon restart,
 it takes one record at a time from the logs to apply to the restoring state. 
 | 
| StateRestoreListener | 
 Class for listening to various states of the restoration process of a StateStore. 
 | 
| StateStore | 
 A storage engine for managing state maintained by a stream processor. 
 | 
| StateStoreSupplier<T extends StateStore> | Deprecated.
 use  
StoreSupplier | 
| StreamPartitioner<K,V> | 
 Determine how records are distributed among the partitions in a Kafka topic. 
 | 
| TimestampExtractor | 
 An interface that allows the Kafka Streams framework to extract a timestamp from an instance of  
ConsumerRecord. | 
| TopicNameExtractor<K,V> | 
 An interface that allows to dynamically determine the name of the Kafka topic to send at the sink node of the topology. 
 | 
| Class | Description | 
|---|---|
| AbstractNotifyingBatchingRestoreCallback | 
 Abstract implementation of the   
BatchingStateRestoreCallback used for batch restoration operations. | 
| AbstractNotifyingRestoreCallback | 
 Abstract implementation of the   
StateRestoreCallback used for batch restoration operations. | 
| AbstractProcessor<K,V> | 
 An abstract implementation of  
Processor that manages the ProcessorContext instance and provides default no-op
 implementation of AbstractProcessor.close(). | 
| DefaultPartitionGrouper | 
 Default implementation of the  
PartitionGrouper interface that groups partitions by the partition id. | 
| FailOnInvalidTimestamp | 
 Retrieves embedded metadata timestamps from Kafka messages. 
 | 
| LogAndSkipOnInvalidTimestamp | 
 Retrieves embedded metadata timestamps from Kafka messages. 
 | 
| MockProcessorContext | 
MockProcessorContext is a mock of ProcessorContext for users to test their Processor,
 Transformer, and ValueTransformer implementations. | 
| MockProcessorContext.CapturedForward | |
| MockProcessorContext.CapturedPunctuator | 
MockProcessorContext.CapturedPunctuator holds captured punctuators, along with their scheduling information. | 
| TaskId | 
 The task ID representation composed as topic group ID plus the assigned partition ID. 
 | 
| TaskMetadata | 
 Represents the state of a single task running within a  
KafkaStreams application. | 
| ThreadMetadata | 
 Represents the state of a single thread running within a  
KafkaStreams application. | 
| To | 
 This class is used to provide the optional parameters when sending output records to downstream processor
 using  
ProcessorContext.forward(Object, Object, To). | 
| UsePreviousTimeOnInvalidTimestamp | 
 Retrieves embedded metadata timestamps from Kafka messages. 
 | 
| WallclockTimestampExtractor | 
 Retrieves current wall clock timestamps as  
System.currentTimeMillis(). | 
| Enum | Description | 
|---|---|
| PunctuationType | 
 Controls what notion of time is used for punctuation scheduled via  
ProcessorContext.schedule(long, PunctuationType, Punctuator) schedule}:
 
   STREAM_TIME - uses "stream time", which is advanced by the processing of messages
   in accordance with the timestamp as extracted by the TimestampExtractor in use. |