Basic Scala Errors That Make No Sense

I'm trying to get a function to compile/work in scala, and getting several absolutely inane error messages that I just can't make sense of. If I write my code like this:

def checkUniqueReviewNumber(number: String): Boolean = {
    val qc = new QualityClient
    if(review.isEmpty)
      false
    else {
      val qrList = qc.listInPL(Vars.currentPLId.get.get,null,null,null,null,null,null,false,false,CurrentUser.getUser.key).qualityReviews
      !qrList.exists(qr:QualityReview => qr.reviewNumber == number)
    }
  }

I get the error:

.../QualityReviewCreate.scala:189: error: not found: type ==
   [scalac]       !qrList.exists(qr:QualityReview => qr.reviewNumber == number)

And if I write the code more like this:

def checkUniqueReviewNumber(number: String): Boolean = {
    val qc = new QualityClient
    if(review.isEmpty)
      false
    else {
      val qrList = qc.listInPL(Vars.currentPLId.get.get,null,null,null,null,null,null,false,false,CurrentUser.getUser.key).qualityReviews
      !qrList.exists(qr:QualityReview => qr.reviewNumber.equals(number))
    }
  }

I get the errors:

... /QualityReviewCreate.scala:189: error: ')' expected but '(' found.
   [scalac]       !qrList.exists(qr:QualityReview => qr.reviewNumber.equals(number))
   [scalac]                                                                ^
    ... /QualityReviewCreate.scala:189: error: ';' expected but ')' found.
   [scalac]       !qrList.exists(qr:QualityReview => qr.reviewNumber.equals(number))
   [scalac]                                                                        ^
   [scalac] two errors found

The types involved may be contributing here, but if so I'm absolutely confused as to why. qrList should be a java ArrayList of QualityReview, which is a java object with a java String field called reviewNumber.

Does anyone understand what's going on here?