We could have written something using Apache commons-collections, but I doubt if we would have liked the end result. Using (inner) callback classes implementing "Transformer" will always contain a lot of ugly Java boiler plate code.
I wondered how would it look in Scala, given my very limited knowledge of this language?
package tungOutput:
object Tester {
def main(args: Array[String]): Unit = {
/* Create two separate lists of Person objects, containing ID and name. */
var personList1 = List(new Person(1, "john"), new Person(2, "john"), new Person(3, "daisy"), new Person(3, "bart"))
var personList2 = List(new Person(100, "bart"), new Person(101, "john"), new Person(103, "daisy"), new Person(104, "daisy"))
System.out.println(personList1)
System.out.println(personList2)
// Now doing the actual test to check if same names are available
val names1 = personList1.map(_.name).distinct.sort((x, y) => x < y)
val names2 = personList2.map(_.name).distinct.sort((x, y) => x < y)
val equalNames = names1 == names2
// Printing some output
System.out.println(names1)
System.out.println(names2)
System.out.println("names from lists are equal = " + equalNames)
}
}
List(tung.Person@199a0c7c, tung.Person@33f42b49, tung.Person@6345e044, tung.Person@86c347)As you can see, the actual tests are 3 simple lines. Probably shorter variations exist, but I'm not the Scala guru. Other languages can do something similar, but the same simplicity with pure Java 6? I don't think so.
List(tung.Person@f7e6a96, tung.Person@3487a5cc, tung.Person@35960f05, tung.Person@eb42cbf)
List(bart, daisy, john)
List(bart, daisy, john)
names from lists are equal = true
Ending note: in the end, he simply chose to write a custom SQL query because of the probable hassle in Java. Would he have done the same if he could use Scala?
