org.apache.kafka.streams.processor

Class MockProcessorContext

java.lang.Object

org.apache.kafka.streams.processor.MockProcessorContext

All Implemented Interfaces:

org.apache.kafka.streams.processor.internals.RecordCollector.Supplier, ProcessorContext

@InterfaceStability.Evolving
public class MockProcessorContext
extends java.lang.Object
implements ProcessorContext, org.apache.kafka.streams.processor.internals.RecordCollector.Supplier

MockProcessorContext is a mock of ProcessorContext for users to test their Processor, Transformer, and ValueTransformer implementations.

The tests for this class (org.apache.kafka.streams.MockProcessorContextTest) include several behavioral tests that serve as example usage.

Note that this class does not take any automated actions (such as firing scheduled punctuators). It simply captures any data it witnesses. If you require more automated tests, we recommend wrapping your Processor in a minimal source-processor-sink Topology and using the TopologyTestDriver.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MockProcessorContext.CapturedForward
static class	MockProcessorContext.CapturedPunctuator MockProcessorContext.CapturedPunctuator holds captured punctuators, along with their scheduling information.

Constructor Summary

Constructors

Constructor and Description
MockProcessorContext() Create a MockProcessorContext with dummy config and taskId and null stateDir.
MockProcessorContext(java.util.Properties config) Create a MockProcessorContext with dummy taskId and null stateDir.
MockProcessorContext(java.util.Properties config, TaskId taskId, java.io.File stateDir) Create a MockProcessorContext with a specified taskId and null stateDir.

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.lang.String,java.lang.Object>	appConfigs() Returns all the application config properties as key/value pairs.
java.util.Map<java.lang.String,java.lang.Object>	appConfigsWithPrefix(java.lang.String prefix) Returns all the application config properties with the given key prefix, as key/value pairs stripping the prefix.
java.lang.String	applicationId() Returns the application id
void	commit() Requests a commit
boolean	committed() Whether ProcessorContext.commit() has been called in this context.
<K,V> void	forward(K key, V value) Forwards a key/value pair to all downstream processors.
<K,V> void	forward(K key, V value, int childIndex) Forwards a key/value pair to one of the downstream processors designated by childIndex
<K,V> void	forward(K key, V value, java.lang.String childName) Forwards a key/value pair to one of the downstream processors designated by the downstream processor name
<K,V> void	forward(K key, V value, To to) Forwards a key/value pair to the specified downstream processors.
java.util.List<MockProcessorContext.CapturedForward>	forwarded() Get all the forwarded data this context has observed.
java.util.List<MockProcessorContext.CapturedForward>	forwarded(java.lang.String childName) Get all the forwarded data this context has observed for a specific child by name.
StateStore	getStateStore(java.lang.String name) Get the state store given the store name.
Headers	headers() Returns the headers of the current input record; could be null if it is not available
Serde<?>	keySerde() Returns the default key serde
StreamsMetrics	metrics() Returns Metrics instance
long	offset() Returns the offset of the current input record; could be -1 if it is not available (for example, if this method is invoked from the punctuate call)
int	partition() Returns the partition id of the current input record; could be -1 if it is not available (for example, if this method is invoked from the punctuate call)
org.apache.kafka.streams.processor.internals.RecordCollector	recordCollector()
void	register(StateStore store, StateRestoreCallback stateRestoreCallbackIsIgnoredInMock) Registers and possibly restores the specified storage engine.
void	resetCommit() Reset the commit capture to false (whether or not it was previously true).
void	resetForwards() Clear the captured forwarded data.
Cancellable	schedule(java.time.Duration interval, PunctuationType type, Punctuator callback) Schedules a periodic operation for processors.
Cancellable	schedule(long intervalMs, PunctuationType type, Punctuator callback) Deprecated.
java.util.List<MockProcessorContext.CapturedPunctuator>	scheduledPunctuators() Get the punctuators scheduled so far.
void	setHeaders(Headers headers) The context exposes this metadata for use in the processor.
void	setOffset(long offset) The context exposes this metadata for use in the processor.
void	setPartition(int partition) The context exposes this metadata for use in the processor.
void	setRecordMetadata(java.lang.String topic, int partition, long offset, Headers headers, long timestamp) The context exposes these metadata for use in the processor.
void	setTimestamp(long timestamp) The context exposes this metadata for use in the processor.
void	setTopic(java.lang.String topic) The context exposes this metadata for use in the processor.
java.io.File	stateDir() Returns the state directory for the partition.
TaskId	taskId() Returns the task id
long	timestamp() Returns the current timestamp.
java.lang.String	topic() Returns the topic name of the current input record; could be null if it is not available (for example, if this method is invoked from the punctuate call)
Serde<?>	valueSerde() Returns the default value serde

Methods inherited from class java.lang.Object

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

Constructor Detail

MockProcessorContext

public MockProcessorContext()

Create a MockProcessorContext with dummy config and taskId and null stateDir. Most unit tests using this mock won't need to know the taskId, and most unit tests should be able to get by with the InMemoryKeyValueStore, so the stateDir won't matter.

MockProcessorContext

public MockProcessorContext(java.util.Properties config)

Create a MockProcessorContext with dummy taskId and null stateDir. Most unit tests using this mock won't need to know the taskId, and most unit tests should be able to get by with the InMemoryKeyValueStore, so the stateDir won't matter.

Parameters:

config - a Properties object, used to configure the context and the processor.

MockProcessorContext

public MockProcessorContext(java.util.Properties config,
                            TaskId taskId,
                            java.io.File stateDir)

Create a MockProcessorContext with a specified taskId and null stateDir.

Parameters:

config - a Properties object, used to configure the context and the processor.

taskId - a TaskId, which the context makes available via taskId().

stateDir - a File, which the context makes available viw stateDir().

Method Detail

applicationId

public java.lang.String applicationId()

Description copied from interface: ProcessorContext

Returns the application id

Specified by:

applicationId in interface ProcessorContext

Returns:

the application id

taskId

public TaskId taskId()

Description copied from interface: ProcessorContext

Returns the task id

Specified by:

taskId in interface ProcessorContext

Returns:

the task id

appConfigs

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

Description copied from interface: ProcessorContext

Returns all the application config properties as key/value pairs. The config properties are defined in the StreamsConfig object and associated to the ProcessorContext.

The type of the values is dependent on the type of the property (e.g. the value of DEFAULT_KEY_SERDE_CLASS_CONFIG will be of type Class, even if it was specified as a String to StreamsConfig(Map)).

Specified by:

appConfigs in interface ProcessorContext

Returns:

all the key/values from the StreamsConfig properties

appConfigsWithPrefix

public java.util.Map<java.lang.String,java.lang.Object> appConfigsWithPrefix(java.lang.String prefix)

Description copied from interface: ProcessorContext

Returns all the application config properties with the given key prefix, as key/value pairs stripping the prefix. The config properties are defined in the StreamsConfig object and associated to the ProcessorContext.

Specified by:

appConfigsWithPrefix in interface ProcessorContext

Parameters:

prefix - the properties prefix

Returns:

the key/values matching the given prefix from the StreamsConfig properties.

keySerde

public Serde<?> keySerde()

Description copied from interface: ProcessorContext

Returns the default key serde

Specified by:

keySerde in interface ProcessorContext

Returns:

the key serializer

valueSerde

public Serde<?> valueSerde()

Description copied from interface: ProcessorContext

Returns the default value serde

Specified by:

valueSerde in interface ProcessorContext

Returns:

the value serializer

stateDir

public java.io.File stateDir()

Description copied from interface: ProcessorContext

Returns the state directory for the partition.

Specified by:

stateDir in interface ProcessorContext

Returns:

the state directory

metrics

public StreamsMetrics metrics()

Description copied from interface: ProcessorContext

Returns Metrics instance

Specified by:

metrics in interface ProcessorContext

Returns:

StreamsMetrics

setRecordMetadata

public void setRecordMetadata(java.lang.String topic,
                              int partition,
                              long offset,
                              Headers headers,
                              long timestamp)

The context exposes these metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set them directly.

Parameters:

topic - A topic name

partition - A partition number

offset - A record offset

timestamp - A record timestamp

setTopic

public void setTopic(java.lang.String topic)

The context exposes this metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set it directly. Setting this attribute doesn't affect the others.

Parameters:

topic - A topic name

setPartition

public void setPartition(int partition)

The context exposes this metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set it directly. Setting this attribute doesn't affect the others.

Parameters:

partition - A partition number

setOffset

public void setOffset(long offset)

The context exposes this metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set it directly. Setting this attribute doesn't affect the others.

Parameters:

offset - A record offset

setHeaders

public void setHeaders(Headers headers)

The context exposes this metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set it directly. Setting this attribute doesn't affect the others.

Parameters:

headers - Record headers

setTimestamp

public void setTimestamp(long timestamp)

The context exposes this metadata for use in the processor. Normally, they are set by the Kafka Streams framework, but for the purpose of driving unit tests, you can set it directly. Setting this attribute doesn't affect the others.

Parameters:

timestamp - A record timestamp

topic

public java.lang.String topic()

Description copied from interface: ProcessorContext

Returns the topic name of the current input record; could be null if it is not available (for example, if this method is invoked from the punctuate call)

Specified by:

topic in interface ProcessorContext

Returns:

the topic name

partition

public int partition()

Description copied from interface: ProcessorContext

Returns the partition id of the current input record; could be -1 if it is not available (for example, if this method is invoked from the punctuate call)

Specified by:

partition in interface ProcessorContext

Returns:

the partition id

offset

public long offset()

Description copied from interface: ProcessorContext

Returns the offset of the current input record; could be -1 if it is not available (for example, if this method is invoked from the punctuate call)

Specified by:

offset in interface ProcessorContext

Returns:

the offset

headers

public Headers headers()

Description copied from interface: ProcessorContext

Returns the headers of the current input record; could be null if it is not available

Specified by:

headers in interface ProcessorContext

Returns:

the headers

timestamp

public long timestamp()

Description copied from interface: ProcessorContext

Returns the current timestamp. If it is triggered while processing a record streamed from the source processor, timestamp is defined as the timestamp of the current input record; the timestamp is extracted from ConsumerRecord by TimestampExtractor. If it is triggered while processing a record generated not from the source processor (for example, if this method is invoked from the punctuate call), timestamp is defined as the current task's stream time, which is defined as the smallest among all its input stream partition timestamps.

Specified by:

timestamp in interface ProcessorContext

Returns:

the timestamp

register

public void register(StateStore store,
                     StateRestoreCallback stateRestoreCallbackIsIgnoredInMock)

Description copied from interface: ProcessorContext

Registers and possibly restores the specified storage engine.

Specified by:

register in interface ProcessorContext

Parameters:

store - the storage engine

stateRestoreCallbackIsIgnoredInMock - the restoration callback logic for log-backed state stores upon restart

getStateStore

public StateStore getStateStore(java.lang.String name)

Description copied from interface: ProcessorContext

Get the state store given the store name.

Specified by:

getStateStore in interface ProcessorContext

Parameters:

name - The store name

Returns:

The state store instance

schedule

@Deprecated
public Cancellable schedule(long intervalMs,
                                        PunctuationType type,
                                        Punctuator callback)

Deprecated.

Description copied from interface: ProcessorContext

Schedules a periodic operation for processors. A processor may call this method during initialization or processing to schedule a periodic callback — called a punctuation — to Punctuator.punctuate(long). The type parameter controls what notion of time is used for punctuation:

• PunctuationType.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. The first punctuation will be triggered by the first record that is processed. NOTE: Only advanced if messages arrive
• PunctuationType.WALL_CLOCK_TIME — uses system time (the wall-clock time), which is advanced independent of whether new messages arrive. The first punctuation will be triggered after interval has elapsed. NOTE: This is best effort only as its granularity is limited by how long an iteration of the processing loop takes to complete

Skipping punctuations: Punctuations will not be triggered more than once at any given timestamp. This means that "missed" punctuation will be skipped. It's possible to "miss" a punctuation if:

• with PunctuationType.STREAM_TIME, when stream time advances more than interval
• with PunctuationType.WALL_CLOCK_TIME, on GC pause, too short interval, ...

Specified by:

schedule in interface ProcessorContext

Parameters:

intervalMs - the time interval between punctuations in milliseconds

type - one of: PunctuationType.STREAM_TIME, PunctuationType.WALL_CLOCK_TIME

callback - a function consuming timestamps representing the current stream or system time

Returns:

a handle allowing cancellation of the punctuation schedule established by this method

schedule

public Cancellable schedule(java.time.Duration interval,
                            PunctuationType type,
                            Punctuator callback)
                     throws java.lang.IllegalArgumentException

Description copied from interface: ProcessorContext

Schedules a periodic operation for processors. A processor may call this method during initialization or processing to schedule a periodic callback — called a punctuation — to Punctuator.punctuate(long). The type parameter controls what notion of time is used for punctuation:

• PunctuationType.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. The first punctuation will be triggered by the first record that is processed. NOTE: Only advanced if messages arrive
• PunctuationType.WALL_CLOCK_TIME — uses system time (the wall-clock time), which is advanced independent of whether new messages arrive. The first punctuation will be triggered after interval has elapsed. NOTE: This is best effort only as its granularity is limited by how long an iteration of the processing loop takes to complete

Skipping punctuations: Punctuations will not be triggered more than once at any given timestamp. This means that "missed" punctuation will be skipped. It's possible to "miss" a punctuation if:

• with PunctuationType.STREAM_TIME, when stream time advances more than interval
• with PunctuationType.WALL_CLOCK_TIME, on GC pause, too short interval, ...

Specified by:

schedule in interface ProcessorContext

Parameters:

interval - the time interval between punctuations (supported minimum is 1 millisecond)

type - one of: PunctuationType.STREAM_TIME, PunctuationType.WALL_CLOCK_TIME

callback - a function consuming timestamps representing the current stream or system time

Returns:

a handle allowing cancellation of the punctuation schedule established by this method

Throws:

java.lang.IllegalArgumentException

scheduledPunctuators

public java.util.List<MockProcessorContext.CapturedPunctuator> scheduledPunctuators()

Get the punctuators scheduled so far. The returned list is not affected by subsequent calls to schedule(...).

Returns:

A list of captured punctuators.

forward

public <K,V> void forward(K key,
                          V value)

Description copied from interface: ProcessorContext

Forwards a key/value pair to all downstream processors. Used the input record's timestamp as timestamp for the output record.

Specified by:

forward in interface ProcessorContext

Parameters:

key - key

value - value

forward

public <K,V> void forward(K key,
                          V value,
                          To to)

Description copied from interface: ProcessorContext

Forwards a key/value pair to the specified downstream processors. Can be used to set the timestamp of the output record.

Specified by:

forward in interface ProcessorContext

Parameters:

key - key

value - value

to - the options to use when forwarding

forward

public <K,V> void forward(K key,
                          V value,
                          int childIndex)

Description copied from interface: ProcessorContext

Forwards a key/value pair to one of the downstream processors designated by childIndex

Specified by:

forward in interface ProcessorContext

Parameters:

key - key

value - value

childIndex - index in list of children of this node

forward

public <K,V> void forward(K key,
                          V value,
                          java.lang.String childName)

Description copied from interface: ProcessorContext

Forwards a key/value pair to one of the downstream processors designated by the downstream processor name

Specified by:

forward in interface ProcessorContext

Parameters:

key - key

value - value

childName - name of downstream processor

forwarded

public java.util.List<MockProcessorContext.CapturedForward> forwarded()

Get all the forwarded data this context has observed. The returned list will not be affected by subsequent interactions with the context. The data in the list is in the same order as the calls to forward(...).

Returns:

A list of key/value pairs that were previously passed to the context.

forwarded

public java.util.List<MockProcessorContext.CapturedForward> forwarded(java.lang.String childName)

Get all the forwarded data this context has observed for a specific child by name. The returned list will not be affected by subsequent interactions with the context. The data in the list is in the same order as the calls to forward(...).

Parameters:

childName - The child name to retrieve forwards for

Returns:

A list of key/value pairs that were previously passed to the context.

resetForwards

public void resetForwards()

Clear the captured forwarded data.

commit

public void commit()

Description copied from interface: ProcessorContext

Requests a commit

Specified by:

commit in interface ProcessorContext

committed

public boolean committed()

Whether ProcessorContext.commit() has been called in this context.

Returns:

true iff ProcessorContext.commit() has been called in this context since construction or reset.

resetCommit

public void resetCommit()

Reset the commit capture to false (whether or not it was previously true).

recordCollector

public org.apache.kafka.streams.processor.internals.RecordCollector recordCollector()

Specified by:

recordCollector in interface org.apache.kafka.streams.processor.internals.RecordCollector.Supplier