Get case object from Scala Object

Question

How to access the CALL_INDEX object from java class:

MyStrategy.scala

trait CallStrategy 
object CallStrategy {
  case object CALL_INDEX extends CallStrategy 
}

trait MyStrategy { def random(as: CallStrategy) } 

object MyStrategy extends MyStrategy 
{
   def random(as: CallStrategy) = { //Some code }
}

In another scala file I can access the CALL_INDEX using: CallStrategy.CALL_INDEX

But in java, I am not able to access it as follows:

StrategyUser.java

CallStrategy$ callStrategy = CallStrategy$.MODULE$;
MyStrategy$ myStrategy = MyStrategy$.MODULE$;
myStrategy.random(callStrategy); // compile time error

The above java code is giving compile time error:

The method random(CallStrategy) in the type MyStrategy$ is not applicable for the arguments (CallStrategy$)

I used the above java code by taking help from:

How do I "get" a Scala case object from Java?

UPDATE:

Please see the image below for clarification:

Even I added two more statements in the code and still the same compile time error:

Answer 1

CallStrategy callStrategy = CallStrategy$.MODULE$.CALL_INDEX$.MODULE$

您当前的代码根本没有提到CALL_INDEX ：它等同于Scala中的MyStrategy.random(CallStrategy) 。

Answer 2

You should do something like below:

MyStrategy$.MODULE$.random(CallStrategy.CALL_INDEX$.MODULE$);

In your code you are trying to access the CALL_INDEX from CallStrategy object, rather, it's available in CallStrategy interface.

Update 1: (Full Code)

MyStrategy.scala:

trait CallStrategy

object CallStrategy {
  case object CALL_INDEX extends CallStrategy
}

trait MyStrategy {
  def random(as: CallStrategy)
}

object MyStrategy extends MyStrategy {
  def random(as: CallStrategy) = {
    println(as)
  }
}

StrategyUser.java:

public class StrategyUser {
    public static void main(String[] args) {
        MyStrategy$.MODULE$.random(CallStrategy.CALL_INDEX$.MODULE$);
    }
}

And FYI, I am using scala version '2.11.7' and java version '1.7.0_75'