org.apache.flink.cep.functions

Class PatternProcessFunction<IN,OUT>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.cep.functions.PatternProcessFunction<IN,OUT>

Type Parameters:

IN - type of incoming elements

OUT - type of produced elements based on found matches

All Implemented Interfaces:

Serializable, Function, RichFunction

Direct Known Subclasses:

PatternFlatSelectAdapter, PatternSelectAdapter

@PublicEvolving
public abstract class PatternProcessFunction<IN,OUT>
extends AbstractRichFunction

It is called with a map of detected events which are identified by their names. The names are defined by the Pattern specifying the sought-after pattern. This is the preferred way to process found matches.

 PatternStream<IN> pattern = ...

 DataStream<OUT> result = pattern.process(new MyPatternProcessFunction());
 

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	PatternProcessFunction.Context Gives access to time related characteristics as well as enables emitting elements to side outputs.

Constructor Summary

Constructors

Constructor and Description
PatternProcessFunction()

Method Summary

Modifier and Type	Method and Description
abstract void	processMatch(Map<String,List<IN>> match, PatternProcessFunction.Context ctx, Collector<OUT> out) Generates resulting elements given a map of detected pattern events.

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

PatternProcessFunction

public PatternProcessFunction()

Method Detail

processMatch

public abstract void processMatch(Map<String,List<IN>> match,
                                  PatternProcessFunction.Context ctx,
                                  Collector<OUT> out)
                           throws Exception

Generates resulting elements given a map of detected pattern events. The events are identified by their specified names.

TimeContext.timestamp() in this case returns the time of the last element that was assigned to the match, resulting in this partial match being finished.

Parameters:

match - map containing the found pattern. Events are identified by their names.

ctx - enables access to time features and emitting results through side outputs

out - Collector used to output the generated elements

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.