5
考虑以下的类:斯卡拉案例类等于实现
trait ModelWithId {
var id: Long = 0
}
case class EntityAttribute (
val entityId: UUID,
val attrName: String,
val stringVal: Option[String],
val boolVal: Option[Boolean],
val longVal: Option[Long],
val doubleVal: Option[Double],
val byteVal: Option[Array[Byte]]) extends ModelWithId{
override def toString() : String = {
"EntityAttribute(" + entityId.hashCode + "," + attrName.hashCode + "," +
stringVal.map{_.hashCode}.getOrElse(None) + "," + stringVal.hashCode+ "," +
boolVal.map{_.hashCode}.getOrElse(None) + "," + boolVal.hashCode+ "," +
longVal.map{_.hashCode}.getOrElse(None) + "," + longVal.hashCode+ "," +
doubleVal.map{_.hashCode}.getOrElse(None) + "," + doubleVal.hashCode+ "," +
byteVal.map{_.hashCode}.getOrElse(None) + ")"
}
}
而且下面的对比功能:
val newAtttributes : List[EntityAttribute]
val withoutIds : List[EntityAttribute]
println("without: " + withoutIds)
println("new: " + newAtttributes)
val differences = newAtttributes.diff(withoutIds)
println("diff: " + differences)
if(newAtttributes.size == 1 && withoutIds.size == 1){
println("==: " + (newAtttributes.get(0) == withoutIds.get(0)))
println("equals: " + (newAtttributes.get(0).equals(withoutIds.get(0))))
println("hequals: " + (newAtttributes.get(0).hashCode == withoutIds.get(0).hashCode))
}
我得到预想的不同输出99 100次。偶尔diff函数会返回一个空列表,当它应该是一个列表。
实施例:
without: List(EntityAttribute(428861607,-1147340381,None,120224,None,120224,56,-356863126,None,120224,None))
new: List(EntityAttribute(428861607,-1147340381,None,120224,None,120224,23,424930523,None,120224,None))
diff: List()
==: false
equals: false
hequals: false
我能够可靠通常围绕后10-18迭代重现此错误。这两个名单来自不同的来源,所以它们的构造方式不同。我猜测它与自动装箱或hashCode的一个糟糕的实现有关,但我一直没有进展就将我的头撞到了墙上2天。
我正在使用scala 2.9.0-1。
您可以打印实际值,以便我们实际上可以重现问题... –
您是不是忘记'extends'ModelWithId {'后? –