Question

What Scala feature can help a class become a factory? And return persistent objects like database connections?

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I am most familiar with Python, less familiar with Java and spent only a few hours with Scala (tutorials). I am working the counter-intuitive ideas about Scala classes into my head; so I am thinking in terms of more intuitive features.

Answer 1

See companion object in scala:

class Example(val string:String) {
  private var extraData = ""
  override def toString = string+extraData
}
object Example {
  def apply(base:String, extras:String) = {
    val s = new Example(base)
    s.extraData = extras
    s
  }
  def apply(base:String) = new Example(base)
}
println(Example("hello"," world"))
println(Example("hello"))

There are connected with class with the same name.

For persistence objects scala use the same stuff as java – jpa hibernate openlink

See Using JPA With Scala