Implementing a java interface in Scala

scala

Solution

You need to supply type parameters to the final method call. You are going through the raw type interface and scala cannot reconstruct the type information.

val cache = new MapMaker().softValues().expiration(30,
TimeUnit.DAYS).makeComputingMap[String, Int](
   new com.google.common.base.Function[String,Int] {
      def apply(key:String):Int ={
        1
     }
   })

Problem

I have the following code for building a cache using google collections: ``` val cache = new MapMaker().softValues().expiration(30, TimeUnit.DAYS).makeComputingMap( new com.google.common.base.Function[String,Int] { def apply(key:String):Int ={ 1 } }) ``` And I am getting the following error message: ``` error: type mismatch; found : java.lang.Object with com.google.common.base.Function[java.lang.String,Int]{ ... } required: com.google.common.base.Function[?, ?] new com.google.common.base.Function[String,Int] { ^ ``` I am wondering why the types don't match ? The actual code is: ``` import com.google.common.collect.MapMaker trait DataCache[V] { private val cache = new MapMaker().softValues().makeComputingMap( new com.google.common.base.Function[String,V] { def apply(key:String):V = null.asInstanceOf[V] }) def get(key:String):V = cache.get(key) } ``` Kind regards, Ali PS - I am using google-collections v1

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