org.apache.samza.system.descriptors

Class StreamDescriptor<StreamMessageType,SubClass extends StreamDescriptor<StreamMessageType,SubClass>>

java.lang.Object

org.apache.samza.system.descriptors.StreamDescriptor<StreamMessageType,SubClass>

Type Parameters:

StreamMessageType - type of messages in this stream.

SubClass - type of the concrete sub-class

Direct Known Subclasses:

InputDescriptor, OutputDescriptor

public abstract class StreamDescriptor<StreamMessageType,SubClass extends StreamDescriptor<StreamMessageType,SubClass>>
extends java.lang.Object

A StreamDescriptor can be used for specifying Samza and system-specific properties of input/output streams.

Stream properties provided in configuration override corresponding properties specified using a descriptors.

This is the base descriptor for an input/output stream. Use a system-specific input/output descriptor (e.g. KafkaInputDescriptor) obtained from its system descriptor (e.g. KafkaSystemDescriptor) if one is available. Otherwise use the GenericInputDescriptor and GenericOutputDescriptor obtained from a GenericSystemDescriptor.

Method Summary

Modifier and Type	Method and Description
java.util.Optional<java.lang.String>	getPhysicalName()
Serde	getSerde()
java.lang.String	getStreamId()
SystemDescriptor	getSystemDescriptor()
java.lang.String	getSystemName()
java.util.Map<java.lang.String,java.lang.String>	toConfig()
protected SubClass	withPhysicalName(java.lang.String physicalName) The physical name of the stream on the system on which this stream will be accessed.
SubClass	withStreamConfigs(java.util.Map<java.lang.String,java.lang.String> streamConfigs) Additional system-specific properties for this stream.

Methods inherited from class java.lang.Object

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

Method Detail

withPhysicalName

protected SubClass withPhysicalName(java.lang.String physicalName)

The physical name of the stream on the system on which this stream will be accessed. This is opposed to the streamId which is the logical name that Samza uses to identify the stream.

A physical name could be a Kafka topic name, an HDFS file URN, or any other system-specific identifier.

If not provided, the logical streamId is used as the physical name.

Parameters:

physicalName - physical name for this stream.

Returns:

this stream descriptor.

withStreamConfigs

public SubClass withStreamConfigs(java.util.Map<java.lang.String,java.lang.String> streamConfigs)

Additional system-specific properties for this stream.

These properties are added under the streams.stream-id.* scope.

Parameters:

streamConfigs - system-specific properties for this stream

Returns:

this stream descriptor

getStreamId

public java.lang.String getStreamId()

getSystemName

public java.lang.String getSystemName()

getSerde

public Serde getSerde()

getSystemDescriptor

public SystemDescriptor getSystemDescriptor()

getPhysicalName

public java.util.Optional<java.lang.String> getPhysicalName()

toConfig

public java.util.Map<java.lang.String,java.lang.String> toConfig()