org.apache.flink.cep.functions.adaptors

Class PatternSelectAdapter<IN,OUT>

java.lang.Object

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

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

org.apache.flink.cep.functions.adaptors.PatternSelectAdapter<IN,OUT>

All Implemented Interfaces:

Serializable, Function, RichFunction

Direct Known Subclasses:

PatternTimeoutSelectAdapter

@Internal
public class PatternSelectAdapter<IN,OUT>
extends PatternProcessFunction<IN,OUT>

Adapter that expresses PatternSelectFunction with PatternProcessFunction.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.cep.functions.PatternProcessFunction

PatternProcessFunction.Context

Constructor Summary

Constructors

Constructor and Description
PatternSelectAdapter(PatternSelectFunction<IN,OUT> selectFunction)

Method Summary

Modifier and Type	Method and Description
void	close() Tear-down method for the user code.
void	open(Configuration parameters) Initialization method for the function.
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

getIterationRuntimeContext, getRuntimeContext, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

PatternSelectAdapter

public PatternSelectAdapter(PatternSelectFunction<IN,OUT> selectFunction)

Method Detail

open

public void open(Configuration parameters)
          throws Exception

Description copied from interface: RichFunction

Initialization method for the function. It is called before the actual working methods (like map or join) and thus suitable for one time setup work. For functions that are part of an iteration, this method will be invoked at the beginning of each iteration superstep.

The configuration object passed to the function can be used for configuration and initialization. The configuration contains all parameters that were configured on the function in the program composition.

 public class MyFilter extends RichFilterFunction<String> {

     private String searchString;

     public void open(Configuration parameters) {
         this.searchString = parameters.getString("foo");
     }

     public boolean filter(String value) {
         return value.equals(searchString);
     }
 }
 

By default, this method does nothing.

Specified by:

open in interface RichFunction

Overrides:

open in class AbstractRichFunction

Parameters:

parameters - The configuration containing the parameters attached to the contract.

Throws:

Exception - Implementations may forward exceptions, which are caught by the runtime. When the runtime catches an exception, it aborts the task and lets the fail-over logic decide whether to retry the task execution.

See Also:

Configuration

close

public void close()
           throws Exception

Description copied from interface: RichFunction

Tear-down method for the user code. It is called after the last call to the main working methods (e.g. map or join). For functions that are part of an iteration, this method will be invoked after each iteration superstep.

This method can be used for clean up work.

Specified by:

close in interface RichFunction

Overrides:

close in class AbstractRichFunction

Throws:

Exception - Implementations may forward exceptions, which are caught by the runtime. When the runtime catches an exception, it aborts the task and lets the fail-over logic decide whether to retry the task execution.

processMatch

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

Description copied from class: PatternProcessFunction

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.

Specified by:

processMatch in class PatternProcessFunction<IN,OUT>

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.