AVRO-3126: Add support for java records

[ashley-taylor]

To implement this feature, I used a CustomEncoding. Added two new methods to pass the DatumReader/DatumWriter, allowing other CustomEncoding to not have to define an entire custom schema but use a hybrid approach.

With this, I also change AvroEncode to be able to specify at a class level. Feels generically helpful to be able to instrument the class instead of all fields referencing the class.

Used reflection to read the isRecord method from the class class so that it will work on older versions of java.

For records, fields can not be modified or accessed with unsafe offsets reads. Instead, the constructor must be invoked, and reads must be done using either method/field reflection.

To identify the appropriate constructor, I use the order of the fields. Since it is a record and can not be extended, reading the direct fields from the record class is safe.

Make sure you have checked all steps below.

Jira

• My PR addresses the following AVRO-3126 issues

Tests

• My PR adds tests
• CustomEncoder specified at the class Level
• CustomEncoder specified in an interface or superclass
• CustomEncoder using the Record encoder
• Can not test actual java record logic as requires java 17 only test package.

Commits

• My commits all reference Jira issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

• In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public functions and the classes in the PR contain Javadoc that explain what it does

[ashley-taylor]

PR is ready for review.
I cannot test the record logic directly with supporting java 8.
One way I can see doing this is to add another maven module that has java 17 tests only, which is skipped for lower versions. I'm happy to add this module, but I want to ensure I'm not missing something obvious before doing that.
If PR is acceptable, I will squash the commits into a single commit.

[jklamer]

I would love the testing in java 17 module if nothing else but to see some examples of the workflow/use. Lots of really cool stuff here that Im still trying to get my head around!

[ashley-taylor]

@jklamer I have added a java17 module.
I have updated the GitHub workflow to invoke the module hopefully. But unfortunately, PR doesn't currently have the approval to run them.

Also built on top of this branch, I have added polymorphic support.
https://github.com/ashley-taylor/avro/compare/master...ashley-taylor:polymorphic?expand=1
Which I plan on opening if this one gets accepted.

[martin-g]

I've approved the workflow run!

The new CI related code could be simplified. I will do it soon!

I'll let the Java developers to comment on the Java changes!

[ashley-taylor]

@martin-g I noticed a bug in how I had conditionally included the java17 module with a profile.
The version of the java17 module would not increment automatically when performing a release, causing a manual headache.

I changed it always to be included but have the compile and test plugins disabled so that it won't complain about the version of java.
Annoyingly I can't put any logic in the maven properties, so the property to enable it has to be named backwards disableJava17.
This way, the module will be included for lining and release purposes but not actually run the code unless configured to set the flag.
Changed the build.sh script to have a new option to run in java17 mode and add an expression to execute one of the two test steps conditionally.

[martin-g]

We should not merge this PR for branch-1.11 because it will definitely cause problems with the release!
I guess we will have to use JDK 17 for the release process and -release 8 for all old modules. Actually no, this is a module with just test cases, so it does not need to be released at all!

[ashley-taylor]

@martin-g @jklamer
Have added some more tests and squashed the commits.
Is there anything I can do to assist in getting this PR merged?

Thanks

[martin-g]

@ashley-taylor The PR should be reviewed and merged by a committer who knows better the Java SDK.
I review most of the PRs for all SDKs but my main expertise is in the Rust SDK.

[RyanSkraba]

Hello! Thanks for your contribution and for your patience! I've set this fix version for the next major release of Avro (1.12.0, later this year). I know record support would be a great feature to get in.

Do you have a JIRA account so we can assign this JIRA to you and ensure that it's properly taken care of?

[ashley-taylor]

Hi @RyanSkraba thanks for the update

Have added a comment on the Jira ticket

I also have another Branch to address AVRO-1568 Polymorphism that I have built on top of this branch. Looking to open that PR after this one.

[martin-g]

Do you have a JIRA account so we can assign this JIRA to you and ensure that it's properly taken care of?

I tried to add Ashley to the Contributors role in JIRA but there are 5 JIRA users with that (display) name and I am not sure which one to add.

[ashley-taylor]

Do you have a JIRA account so we can assign this JIRA to you and ensure that it's properly taken care of?

I tried to add Ashley to the Contributors role in JIRA but there are 5 JIRA users with that (display) name and I am not sure which one to add.

ashley-taylor

is my jira username

[martin-g]

I know but JIRA offers me 5 users with "Ashley Taylor" as display name when I enter this id:

[ashley-taylor]

I know but JIRA offers me 5 users with "Ashley Taylor" as display name when I enter this id:

I don't know how you did it. But have correctly assigned to the correct one. My name is clearly too common.

[martin-g]

I did nothing! :-)
Someone else did it.

[opwvhk]

Looks like a great addition.
I like the care given to the combination of records, wrapped classes, inheritance and custom encodings. That could otherwise cause bugs.

[ashley-taylor]

anything I can do to help this get merged?

[martin-g]

@ashley-taylor The JIRA ticket has Fix version set to 1.12.0, so it will be reviewed and merged before the release!
I cannot say when 1.12.0 will be released though!

[carl-mastrangelo]

I would like also like to express my interest in this getting merged. We use Avro with our Apache Beam classes, and being able to use Record classes would make things more seamless.

[ashley-taylor]

I have made some additional Java 17 improvements that are based on this and I wondering if I should add this branch.
If the classes are sealed it will automatically add the equivalent of the @union annotation, so polymorphism is automatic.

https://github.com/ashley-taylor/avro/pull/1/files

[JoeryH]

Just wanted to share that record support for Avro would be really nice to have!