Java Destination SPI: start v.s. accept

Connector Development
1

Hi, I’m trying to develop a Java-based Destination, and looking into AirbyteMessageConsumer.

My question here is: What is the difference between start v.s. accept?

I saw some connectors have comment in start (or startTracked) like:

// todo (cgardens) - move contents of #write into this method.

So I guessed implementing everything in accept might somewhat work, but I was not sure of their difference.

Do you have Javadoc for them?

2

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3

There’s some more information in AirbyteMessageConsumer.java:


/**
 * Interface for the destination's consumption of incoming records wrapped in an
 * {@link io.airbyte.protocol.models.AirbyteMessage}.
 *
 * This is via the accept method, which commonly handles parsing, validation, batching and writing
 * of the transformed data to the final destination i.e. the technical system data is being written
 * to.
 *
 * Lifecycle:
 * <ul>
 * <li>1. Instantiate consumer.</li>
 * <li>2. start() to initialize any resources that need to be created BEFORE the consumer consumes
 * any messages.</li>
 * <li>3. Consumes ALL records via {@link AirbyteMessageConsumer#accept(AirbyteMessage)}</li>
 * <li>4. Always (on success or failure) finalize by calling
 * {@link AirbyteMessageConsumer#close()}</li>
 * </ul>
 * We encourage implementing this interface using the {@link FailureTrackingAirbyteMessageConsumer}
 * class.
 */
1 Like
4

Hi @sh4sh,

Ah, thanks. Sorry that I’ve overlooked your response.

Got it. I understood that :

  • start() would be responsible on “initialization” that can be performed before accept() without any parameter (AirbyteMessage)
  • accept() would do anything remaining to consume the actual data with the given parameter (AirbyteMessage)
  • Then, some connectors have had only accept() because it could just work.

I was just curious that Airbyte does not release its Java components to Maven Central, nor publish its Javadocs. But anyway, your informations helps. Thanks!

5

I’m glad that it is helpful! My understanding is that these block comments are compatible with Javadoc so we might already be set up to generate it?

To be honest I’m not very familiar with this, but I agree it would be great to have this spec easily available. Would you be willing to submit a documentation request to our Github repo to publish our Javadoc?

6

If you’re willing to publish Airbyte-related Java components to Maven Central, they would include Javadocs, and that would be the most popular way to publish OSS Javadocs. https://javadoc.io/ (unofficial, but semi de-facto standard OSS Javadoc container) will automatically get Javadocs from Maven Central.

But whether releasing the Java components to Maven Central, or not, would depend on what Airbyte thinks. I can just file a GitHub Issue if it helps.

7

For sure, please submit a request to our Github repo so our team can take a look and users can vote on it! https://github.com/airbytehq/airbyte/issues/new?assignees=&labels=type%2Fenhancement%2C+needs-triage&template=feature-request.md&title=