JRuby 10 / JDK 21 compatibility issue with activerecord-jdbc-adapter (WeakMap error)

[qisantanu]

Summary

I'm trying to use activerecord-jdbc-adapter with JRuby 10 (Java 21), but encountering a runtime error when loading the gem.

It appears to be related to changes in JRuby internals (WeakMap), which may not yet be supported by the adapter.

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Environment

• JRuby: 10.x
• Java: OpenJDK 21
• Rails: 7.2
• activerecord-jdbc-adapter: ~> 70.0
• activerecord-oracle_enhanced-adapter: 7.2.0 (from GitHub)

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Error

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Steps to Reproduce

1. Use JRuby 10 with JDK 21
2. Add the following to Gemfile:

platforms :jruby do
  gem 'activerecord-oracle_enhanced-adapter', '7.2.0', git: 'https://github.com/rsim/oracle-enhanced.git', tag: 'v7.2.0'
  gem 'activerecord-jdbc-adapter', '~> 72.0'
end

Run:

bundle install
rails c

Expected Behavior

The adapter should load correctly and allow establishing a JDBC connection.

Actual Behavior

The application fails to boot due to a WeakMap-related error.

Additional Context

JRuby 10 requires Java 21, so support for this combination would be valuable going forward.
This may be related to internal changes in JRuby’s object space implementation.
Request

Is there any plan to support JRuby 10 / Java 21?

Thanks for maintaining this project 🙏

[rammpeter]

@qisantanu I made a dirty hack in config/boot.rb to workaround the problem

# with oracle-enhanced-adapter 6.1.6 and JRuby 9.4.6.0 and following versions
# Prevent execution of the code block in the if statement by comparing RUBY_ENGINE with a not existing value
# This patches the gem each time it is installed again
# Peter Ramm, 2024-06-18
# See also: https://github.com/rsim/oracle-enhanced/pull/2360

gem_path = Gem::Specification.find_by_name('activerecord-oracle_enhanced-adapter').gem_dir
file_path = File.join(gem_path, 'lib', 'active_record', 'connection_adapters', 'oracle_enhanced_adapter.rb')
content = File.read(file_path)
new_content = content.gsub("if RUBY_ENGINE == \"jruby\"", "if RUBY_ENGINE == \"xjruby\"")
File.open(file_path, 'w') { |file| file.write(new_content) }