Invoke java & scala methods with dollar sign ($) in name

[Nic T]

I had some trouble invoking Java / Scala methods with a dollar sign ($) in their name.

These are methods generated by a pre-compilation step e.g. AVDL code generation.

Other times you may come across them as synthetic methods in Scala bytecode generation.

For example in my case I had a POJO with setUserName$1().

I emailed Barthelemy and he gave me a solution, I'll post here in case others stumble upon this:

You could try py4j.java_gateway.get_method(my_obj, "setUserName$1")

Rgds,

Nic

[Imran Rashid]

old thread, but thought I'd add another useful bit of info here.  I found that if I needed to access a class name with a $ in it, I needed to use __getattr__.  And if its a scala package object, double whammy as that requires extra escaping in the jvm.  eg. to get to to a scala package object defined in org.apache.spark.internal.config, I used

org.apache.spark.internal.config.__getattr__("package$").__getattr__("MODULE$")

[Jonah Graham]

BTW you probably shouldn't be calling __getattr__ directly and you should use getattr() instead -- https://docs.python.org/3/library/functions.html#getattr. Using __getattr__ directly bypasses some of the mechanisms in Python. So I think this should be your line (untested):

package_dollar = getattr(org.apache.spark.internal.config, "package$")

module_dollar = getattr(package_dollar, "MODULE$")

HTH,

Jonah

~~~
Jonah Graham
Kichwa Coders Ltd.
www.kichwacoders.com

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