org.apache.flink.streaming.api.functions.sink

Class PrintSinkFunction<IN>

java.lang.Object

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

org.apache.flink.streaming.api.functions.sink.RichSinkFunction<IN>

org.apache.flink.streaming.api.functions.sink.PrintSinkFunction<IN>

Type Parameters:

IN - Input record type

All Implemented Interfaces:

Serializable, Function, RichFunction, SupportsConcurrentExecutionAttempts, SinkFunction<IN>

@PublicEvolving
public class PrintSinkFunction<IN>
extends RichSinkFunction<IN>
implements SupportsConcurrentExecutionAttempts

Implementation of the SinkFunction writing every tuple to the standard output or standard error stream.

Four possible format options: sinkIdentifier:taskId> output <- sinkIdentifier provided, parallelism > 1 sinkIdentifier> output <- sinkIdentifier provided, parallelism == 1 taskId> output <- no sinkIdentifier provided, parallelism > 1 output <- no sinkIdentifier provided, parallelism == 1

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.streaming.api.functions.sink.SinkFunction

SinkFunction.Context

Constructor Summary

Constructors

Constructor and Description
PrintSinkFunction() Instantiates a print sink function that prints to standard out.
PrintSinkFunction(boolean stdErr) Instantiates a print sink function that prints to standard out.
PrintSinkFunction(String sinkIdentifier, boolean stdErr) Instantiates a print sink function that prints to standard out and gives a sink identifier.

Method Summary

Modifier and Type	Method and Description
void	invoke(IN record)
void	open(Configuration parameters) Initialization method for the function.
String	toString()

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

close, getIterationRuntimeContext, getRuntimeContext, setRuntimeContext

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.streaming.api.functions.sink.SinkFunction

finish, invoke, writeWatermark

Constructor Detail

PrintSinkFunction

public PrintSinkFunction()

Instantiates a print sink function that prints to standard out.

PrintSinkFunction

public PrintSinkFunction(boolean stdErr)

Instantiates a print sink function that prints to standard out.

Parameters:

stdErr - True, if the format should print to standard error instead of standard out.

PrintSinkFunction

public PrintSinkFunction(String sinkIdentifier,
                         boolean stdErr)

Instantiates a print sink function that prints to standard out and gives a sink identifier.

Parameters:

stdErr - True, if the format should print to standard error instead of standard out.

sinkIdentifier - Message that identify sink and is prefixed to the output of the value

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

invoke

public void invoke(IN record)

Specified by:

invoke in interface SinkFunction<IN>

toString

public String toString()

Overrides:

toString in class Object