How do I “get” a Scala case object from Java?

Question

I created a hierarchy of case objects in Scala that looks like the following:

package my.awesome.package

sealed abstract class PresetShapeType(val displayNa         


        

Answer 1

from Java, say:

my.awesome.package.PressureSensor$.MODULE$

Answer 2

This is still a hack, but in my opinion a bit more readable in Java. Just add a method to explicitly return the reference to the singleton instance (it shows up as a static method on the class):

sealed abstract class PresetShapeType(val displayName: String)

case object AccelerationSensor extends PresetShapeType("Acceleration Sensor") { def instance = this }
case object DisplacementSensor extends PresetShapeType("Displacement Sensor") { def instance = this }
case object ForceSensor extends PresetShapeType("Force Sensor") { def instance = this }
case object PressureSensor extends PresetShapeType("Pressure Sensor") { def instance = this }
case object StrainSensor extends PresetShapeType("Strain Sensor") { def instance = this }

And then in Java:

import my.awesome.package.PressureSensor;
DVShape newshape = DVShapeFactory.createPresetShape(PressureSensor.instance(), new Point3f(0,0,0));

Answer 3

PressureSensor$.MODULE$ should give you the instance of the case object.