Package org.apache.flink.cep.pattern.conditions

Class RichIterativeCondition<T>

java.lang.Object

org.apache.flink.cep.pattern.conditions.IterativeCondition<T>

org.apache.flink.cep.pattern.conditions.RichIterativeCondition<T>

All Implemented Interfaces:

Serializable, Function, RichFunction

Direct Known Subclasses:

IterativeConditionRunner, RichCompositeIterativeCondition

public abstract class RichIterativeCondition<T>
extends IterativeCondition<T>
implements RichFunction

Rich variant of the IterativeCondition. As a RichFunction, it gives access to the RuntimeContext and provides setup and teardown methods: RichFunction.open(OpenContext) and RichFunction.close().

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.cep.pattern.conditions.IterativeCondition

IterativeCondition.Context<T>

Constructor Summary

Constructors

Constructor	Description
RichIterativeCondition()

Method Summary

Modifier and Type	Method	Description
void	close()	Tear-down method for the user code.
IterationRuntimeContext	getIterationRuntimeContext()	Gets a specialized version of the RuntimeContext, which has additional information about the iteration in which the function is executed.
RuntimeContext	getRuntimeContext()	Gets the context that contains information about the UDF's runtime, such as the parallelism of the function, the subtask index of the function, or the name of the task that executes the function.
void	open(OpenContext openContext)	Initialization method for the function.
void	setRuntimeContext(RuntimeContext runtimeContext)	Sets the function's runtime context.

Methods inherited from class org.apache.flink.cep.pattern.conditions.IterativeCondition

filter

Methods inherited from class java.lang.Object

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

Constructor Detail

RichIterativeCondition

public RichIterativeCondition()

Method Detail

setRuntimeContext

public void setRuntimeContext(RuntimeContext runtimeContext)

Description copied from interface: RichFunction

Sets the function's runtime context. Called by the framework when creating a parallel instance of the function.

Specified by:

setRuntimeContext in interface RichFunction

Parameters:

runtimeContext - The runtime context.

getRuntimeContext

public RuntimeContext getRuntimeContext()

Description copied from interface: RichFunction

Gets the context that contains information about the UDF's runtime, such as the parallelism of the function, the subtask index of the function, or the name of the task that executes the function.

The RuntimeContext also gives access to the Accumulators and the DistributedCache.

Specified by:

getRuntimeContext in interface RichFunction

Returns:

The UDF's runtime context.

getIterationRuntimeContext

public IterationRuntimeContext getIterationRuntimeContext()

Description copied from interface: RichFunction

Gets a specialized version of the RuntimeContext, which has additional information about the iteration in which the function is executed. This IterationRuntimeContext is only available if the function is part of an iteration. Otherwise, this method throws an exception.

Specified by:

getIterationRuntimeContext in interface RichFunction

Returns:

The IterationRuntimeContext.

open

public void open(OpenContext openContext)
          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 openContext object passed to the function can be used for configuration and initialization. The openContext contains some necessary information that were configured on the function in the program composition.

 public class MyFilter extends RichFilterFunction<String> {

     private String searchString;

     public void open(OpenContext openContext) {
         // initialize the value of searchString
     }

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

Specified by:

open in interface RichFunction

Parameters:

openContext - The context containing information about the context in which the function is opened.

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.

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

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.