如何从Java调用Scala包对象上定义的方法？ （Scala 2.10.x）

Question

Given a method defined on a (3rd party, so I can't just move it) Scala package object, like so:

package foo

package object bar {
  def doSomething(s: String): String = ???
}

I need to call doSomething from Java code. I know that in general, I can get at a Scala companion object's methods from Java using ScalaObject$.method() . However, the example above compiles to foo.bar.package$.class , and of course Java screams about package being a reserved word.

Is there a way to call this from Java directly?

Answer 1

The best I can come up with (works, but ugly) is to wrap doSomething in Scala code that's not in a package object, and then call the wrapper from my Java code.

object BarUtil {
  def wrapper(s: String) = foo.bar.doSomething(s)
}

and in Java

public String doIt(String s) {
    return BarUtil$.wrapper(s);
}

Answer 2

您可以访问包对象foo.bar.package$.MODULE$ （注意美元符号，不要删除它们）：

foo.bar.package$.MODULE$.doSomething("hello")