ProcessorContext (kafka 1.0.1 API)

@InterfaceStability.Evolving
public interface ProcessorContext

Processor context interface.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
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
`<K,V> void`	`forward(K key, V value)` Forwards a key/value pair to the 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
`StateStore`	`getStateStore(java.lang.String name)` Get the state store given the store name.
`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)
`void`	`register(StateStore store, boolean loggingEnabledIsDeprecatedAndIgnored, StateRestoreCallback stateRestoreCallback)` Registers and possibly restores the specified storage engine.
`void`	`schedule(long interval)` Deprecated. Please use `schedule(long, PunctuationType, Punctuator)` instead.
`Cancellable`	`schedule(long interval, PunctuationType type, Punctuator callback)` Schedules a periodic operation for processors.
`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

- Method Detail
  - applicationId
```
java.lang.String applicationId()
```
    Returns the application id
    
    Returns:
    
    the application id
  - taskId
```
TaskId taskId()
```
    Returns the task id
    
    Returns:
    
    the task id
  - keySerde
```
Serde<?> keySerde()
```
    Returns the default key serde
    
    Returns:
    
    the key serializer
  - valueSerde
```
Serde<?> valueSerde()
```
    Returns the default value serde
    
    Returns:
    
    the value serializer
  - stateDir
```
java.io.File stateDir()
```
    Returns the state directory for the partition.
    
    Returns:
    
    the state directory
  - metrics
```
StreamsMetrics metrics()
```
    Returns Metrics instance
    
    Returns:
    
    StreamsMetrics
  - register
```
void register(StateStore store,
              boolean loggingEnabledIsDeprecatedAndIgnored,
              StateRestoreCallback stateRestoreCallback)
```
    Registers and possibly restores the specified storage engine.
    
    Parameters:
    
    store - the storage engine
    
    loggingEnabledIsDeprecatedAndIgnored - deprecated parameter loggingEnabled is ignored: if you want to enable logging on a state stores call StoreBuilder.withLoggingEnabled(Map) when creating the store
    
    Throws:
    
    java.lang.IllegalStateException - If store gets registered after initialized is already finished
    
    StreamsException - if the store's change log does not contain the partition
  - getStateStore
```
StateStore getStateStore(java.lang.String name)
```
    Get the state store given the store name.
    
    Parameters:
    
    name - The store name
    
    Returns:
    
    The state store instance
  - schedule
```
Cancellable schedule(long interval,
                     PunctuationType type,
                     Punctuator callback)
```
    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 at the polling interval (StreamsConfig.POLL_MS_CONFIG) 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, ...
    Parameters:
    
    interval - the time interval between punctuations
    
    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
```
@Deprecated
void schedule(long interval)
```
    Deprecated. Please use schedule(long, PunctuationType, Punctuator) instead.
    
    Schedules a periodic operation for processors. A processor may call this method during initialization to schedule a periodic call - called a punctuation - to Processor.punctuate(long).
    
    Parameters:
    
    interval - the time interval between punctuations
  - forward
```
<K,V> void forward(K key,
                   V value)
```
    Forwards a key/value pair to the downstream processors
    
    Parameters:
    
    key - key
    
    value - value
  - forward
```
<K,V> void forward(K key,
                   V value,
                   int childIndex)
```
    Forwards a key/value pair to one of the downstream processors designated by childIndex
    
    Parameters:
    
    key - key
    
    value - value
    
    childIndex - index in list of children of this node
  - forward
```
<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
    
    Parameters:
    
    key - key
    
    value - value
    
    childName - name of downstream processor
  - commit
```
void commit()
```
    Requests a commit
  - topic
```
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)
    
    Returns:
    
    the topic name
  - partition
```
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)
    
    Returns:
    
    the partition id
  - offset
```
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)
    
    Returns:
    
    the offset
  - timestamp
```
long timestamp()
```
    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.
    
    Returns:
    
    the timestamp
  - appConfigs
```
java.util.Map<java.lang.String,java.lang.Object> appConfigs()
```
    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)).
    
    Returns:
    
    all the key/values from the StreamsConfig properties
  - appConfigsWithPrefix
```
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. The config properties are defined in the StreamsConfig object and associated to the ProcessorContext.
    
    Parameters:
    
    prefix - the properties prefix
    
    Returns:
    
    the key/values matching the given prefix from the StreamsConfig properties.

Interface ProcessorContext

Method Summary

Method Detail

applicationId

taskId

keySerde

valueSerde

stateDir

metrics

register

getStateStore

schedule

schedule

forward

forward

forward

commit

topic

partition

offset

timestamp

appConfigs

appConfigsWithPrefix