implementing java interface with scala class - type issue

Question

Why on earth won't this compile? Scala 2.8.0RC3:

Java

public interface X {
    void logClick(long ts, int cId, String s, double c);
}

Scala

class Y extends X {
  def logClick(ts: Long, cId: Int,sid: java.lang.String,c: Double) : Unit = {
  ...
  }
}

Error

class Y needs to be abstract, since method logClick in trait X of type
(ts: Long,cId: Int,s: java.lang.String,c: Double)Unit is not defined

missingfaktor · Accepted Answer · 2010-06-08 17:02:17Z

2

~~You need to add override before the definition of logClick in class Y.~~

~~class Y extends X { override def logClick(ts: Long, cId: Int,sid: java.lang.String,c: Double) : Unit = { ... } }~~

EDIT:

For the reason Daniel said below, you don't even need to add override before the method. Your code is right as it is.

answered Jun 8, 2010 at 16:20

missingfaktor

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4 Comments

@paintcan, just tested. It works here. What version of Scala are you using?

version is in post, but since you say this worked for you we're going to try to reproduce the issue in a project with all extraneous crap removed

seems like there was an aliasing issue due to an import of java.lang.Double. whoops

You don't really need override when the method being overridden is abstract.