Package org.apache.pulsar.functions.api

Interface Function<X,T>

Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@Public @Stable @FunctionalInterface public interface Function<X,T>
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
    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.
    T
    process(X input, Context context)
    Process the input.

  • Method Details

    • process

      T process(X 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 - if an error occurs

    • close

      default void close() throws Exception
      Called once to properly close resources when function instance is stopped.
      Throws:
      Exception - if an error occurs