How to call a method from java whose name is send?

[AlexeyMatskevich]

I installed pulsar client on java in my truffleruby-jvm 24.0.1 installation, compiled with Gradle 8.7 and tried to use it (I have absolutely no knowledge of Java and don't know how right I am doing everything). Here's an example of how I work with a client:

Java.add_to_classpath("/app/pulsar-java-client/lib/build/libs/lib-all.jar")
pulsar = Java.type('org.apache.pulsar.client.api.PulsarClient')
client = pulsar.builder.serviceUrl(ENV["PULSAR_URL"]).build

producer = client.newProducer.topic("my-topic").create

next step, I try to send a message using the pulsar client documentation as a primary source:

Producer<String> stringProducer = client.newProducer(Schema.STRING)
        .topic("my-topic")
        .create();
stringProducer.send("My message");

Unfortunately, I don't understand how I can call the send (java version) method, given the fact that the ruby Object class already defines this method. Is there any way around this in any way?

[AlexeyMatskevich]

This seems to be done as follows

producer['send'].call(-> {"My message"})

but I seem to be having trouble typing.

producer['send'].call(-> {"My message"})
#<Polyglot::ForeignException[Java] java.lang.ClassCastException:0x71cdc44c: class com.oracle.truffle.polyglot.PolyglotMapAndFunction cannot be cast to class java.lang.String (com.oracle.truffle.polyglot.PolyglotMapAndFunction is in module org.graalvm.truffle of loader 'app'; java.lang.String is in module java.base of loader 'bootstrap')>
backtraces are hidden because TruffleRuby doesn't have a case for the org.truffleruby.language.objects.IsCopyableObjectNodeGen node with values of type com.oracle.truffle.host.HostException
        from org.truffleruby.language.objects.IsCopyableObjectNodeGen.executeAndSpecialize(IsCopyableObjectNodeGen.java:168)
        from org.truffleruby.language.objects.IsCopyableObjectNodeGen.execute(IsCopyableObjectNodeGen.java:113)
        from org.truffleruby.core.kernel.KernelNodesFactory$CloneNodeFactory$CloneNodeGen.executeAndSpecialize(KernelNodesFactory.java:2953)
        from org.truffleruby.core.kernel.KernelNodesFactory$CloneNodeFactory$CloneNodeGen.execute(KernelNodesFactory.java:2935)
        from org.truffleruby.language.control.SequenceNode.execute(SequenceNode.java:38)
        from org.truffleruby.language.RubyMethodRootNode.execute(RubyMethodRootNode.java:65) was raised when processing them

Even if one tries to use Java types (if I'm doing it right)

irb(main):007> ST = Java.type('java.lang.String')
=> #<Polyglot::ForeignClass[Java] type java.lang.String>
irb(main):009> s = ST.new("Hello, world")
=> "Hello, world"
irb(main):012> producer['send'].call(-> {s})
#<Polyglot::ForeignException[Java] java.lang.ClassCastException:0x68d272c7: class com.oracle.truffle.polyglot.PolyglotMapAndFunction cannot be cast to class java.lang.String (com.oracle.truffle.polyglot.PolyglotMapAndFunction is in module org.graalvm.truffle of loader 'app'; java.lang.String is in module java.base of loader 'bootstrap')>
backtraces are hidden because TruffleRuby doesn't have a case for the org.truffleruby.language.objects.IsCopyableObjectNodeGen node with values of type com.oracle.truffle.host.HostException
        from org.truffleruby.language.objects.IsCopyableObjectNodeGen.executeAndSpecialize(IsCopyableObjectNodeGen.java:168)
        from org.truffleruby.language.objects.IsCopyableObjectNodeGen.execute(IsCopyableObjectNodeGen.java:113)
        from org.truffleruby.core.kernel.KernelNodesFactory$CloneNodeFactory$CloneNodeGen.executeAndSpecialize(KernelNodesFactory.java:2953)
        from org.truffleruby.core.kernel.KernelNodesFactory$CloneNodeFactory$CloneNodeGen.execute(KernelNodesFactory.java:2935)
        from org.truffleruby.language.control.SequenceNode.execute(SequenceNode.java:38)
        from org.truffleruby.language.RubyMethodRootNode.execute(RubyMethodRootNode.java:65) was raised when processing them

[eregon]

This works fine:

Dir.glob("pulsar-client/*.jar").each { |f| Java.add_to_classpath File.expand_path f }
pulsar = Java.type('org.apache.pulsar.client.api.PulsarClient')
p pulsar
client = pulsar.builder.serviceUrl("pulsar://localhost:6650/").build
p client

Schema = Java.type('org.apache.pulsar.client.api.Schema')
producer = client.newProducer(Schema.STRING).topic("my-topic").create
p producer

producer[:send].call("My message")
# Or:
Truffle::Interop.invoke_member(producer, :send, "My message")

I followed https://pulsar.apache.org/docs/next/getting-started-standalone/ (including running bin/pulsar standalone) and https://pulsar.apache.org/docs/next/client-libraries-java-setup/ and downloaded all Maven jars to a folder with https://stackoverflow.com/a/75183691/388803

So it's producer[:send].call("My message") not producer['send'].call(-> {"My message"}) which would pass a Proc and not a String. The Schema.STRING is also needed otherwise the API seems to expect [B, i.e. byte[]. There is also Truffle::Interop.invoke_member(producer, :send, "My message") which uses interop explicitly.