org.apache.pulsar.functions.api

Interface Function<I,O>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@InterfaceAudience.Public
 @InterfaceStability.Stable
 @FunctionalInterface
public interface Function<I,O>

This is the core interface of the function api. The process is called for every message of the input topic of the function. The incoming input bytes are converted to the input type I for simple Java types(String, Integer, Boolean, Map, and List types) and for org.Json type. If this serialization approach does not meet your needs, you can use the byte stream handler defined in RawRequestHandler.

Method Summary

Modifier and Type	Method and Description
default void	close() Called once to properly close resources when function instance is stopped.
default void	initialize(Context context) Called once to initialize resources when function instance is started.
O	process(I input, Context context) Process the input.

Method Detail

process

O process(I input,
          Context context)
   throws Exception

Process the input.

Returns:

the output

Throws:

Exception

initialize

default void initialize(Context context)
                 throws Exception

Called once to initialize resources when function instance is started.

Parameters:

context - The Function context

Throws:

Exception

close

default void close()
            throws Exception

Called once to properly close resources when function instance is stopped.

Throws:

Exception