Undefined Method java_kind_of? in JRuby-9.3.0.0

[ThomasKoppensteiner]

(NoMethodError) undefined method `java_kind_of?' for #<Java::ComRabbitmqClientImpl::LongStringHelper::ByteArrayLongString:0xa79c8be> Did you mean? java_send

Environment Information
JRuby: jruby 9.3.0.0 (2.6.8) 2021-09-17 85c20e780f OpenJDK 64-Bit Server VM 11.0.12+0 on 11.0.12+0 [darwin-x86_64]
Dev OS: Darwin ofc-03052-m 20.6.0 Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64 x86_64

java_kind_of? is called here by the march_hare gem (version 4.3.0-java) (ruby-amqp/march_hare#155).

Expected Behavior

• The java_kind_of? method is supported by JRuby-9.3.0.0

Actual Behavior

• The java_kind_of? method is not supported by JRuby-9.3.0.0
• The java_kind_of? method is supported by JRuby-9.2.19.0

Is java_kind_of? deprecated? Is there a replacement in JRuby-9.3.0.0?

[ThomasKoppensteiner]

Is java_kind_of? deprecated?

Yes, it was deprecated in JRuby-9.2.19.0.

See: https://github.com/jruby/jruby/blob/9.2.19.0/core/src/main/ruby/jruby/java/core_ext/object.rb#L13-L19

# @deprecated
def java_kind_of?(other) # TODO: this can go away now, but people may be using it
  return true if self.kind_of?(other)
  return false unless self.respond_to?(:java_class) && other.respond_to?(:java_class) &&
    other.kind_of?(Module) && !self.kind_of?(Module) 
  return other.java_class.assignable_from?(self.java_class)
end

[michaelklishin]

So what are our options then? Use #assignable_from? instead?

[enebo]

@ThomasKoppensteiner @michaelklishin Is kind_of? working for your needs here:

a = java.util.ArrayList.new; p a.kind_of?(java.util.ArrayList) #=> true
a = java.util.ArrayList.new; p a.kind_of?(java.util.List) #=> true

[ThomasKoppensteiner]

@enebo thank you for your suggestion. I used it in this PR for march_hare ruby-amqp/march_hare#156.

[enebo]

@ThomasKoppensteiner we talked about this on chat and realized for instance of sorts of checks kind_of? works but if you ask on Java type itself (e.g. java.util.ArrayList.kind_of?(java.lang.Class)) it does not. I think this is probably very uncommon but if you happen to ever notice this case we probably need to augment kind_of?.

[olleolleolle]

The use-case in the ticket is the following:

value.kind_of(com.rabbitmq.client.LongString) where value seems to be a Java value (we can see checks in there going value.is_a?(java.util.Map)).

@enebo Would this be a valid?

I searched for LONG_STRING_TYPE and found that value. https://github.com/ruby-amqp/march_hare/search?q=LONG_STRING_TYPE

[headius]

Would this be a valid?

I believe these should work with kind_of? or is_a as appropriate. The Ruby view of the Java object uses the same class hierarchy as e.g. com.rabbitmw.client.LongString and it should be seen as a supertype of the object's class.

[headius]

Closing as won't fix since kind_of? should work for all interesting use cases.

[AxelPatron]

Hello, I am using Logstash to process python script in my pipeline between SQL and ElasticSearch but if I use this filter in my logstash-sample.conf file
filter { python { code => ' print("python works") ' } }
I receive these logs :

[2023-05-16T09:26:01,898][ERROR][logstash.filters.python ][main][9159e3828cc8f1ed140577832a7ee56f40772013e30def286e744cbc9c8f7eb1] Python exception occurred: undefined method java_kind_of?' for #Java::OrgPythonCore::PyObjectDerived:0x59f863d5
Did you mean? java_send
python works
python works
[2023-05-16T09:26:01,926][ERROR][logstash.filters.python ][main][9159e3828cc8f1ed140577832a7ee56f40772013e30def286e744cbc9c8f7eb1] Python exception occurred: undefined method java_kind_of?' for #<Java::OrgPythonCore::PyObjectDerived:0x1e55fe7e> Did you mean? java_send python works [2023-05-16T09:26:01,933][ERROR][logstash.filters.python ][main][9159e3828cc8f1ed140577832a7ee56f40772013e30def286e744cbc9c8f7eb1] Python exception occurred: undefined method java_kind_of?' for #Java::OrgPythonCore::PyObjectDerived:0x1e55fe7e`

I am not sure it causes problems but what could I do to prevent that?
I am using Logstash 8.6.2 wich uses JRuby to 9.3.10.0

[enebo]

@AxelPatron I don't know how you insert Ruby into conf (or some other file which happens to be Ruby syntax) but if you figure out such a place you can:

class Object; alias java_kind_of? kind_of?; end

I am guessing java_kind_of? is still being used by whatever provides python support.