Nevertheless, I like the idea to get a more native Scala integration.
For example, I would really love to check out whether it would be hard
to natively support Scala's property semantics besides convetional
getters and setters.
Andreas Joseph Krogh schrieb:
> On Sunday 24 May 2009 09:36:48 pm Andreas Joseph Krogh wrote:
>> Hi all.
>> Normally this kind of post would be better posted to -users, but I'm looking
>> for the developers comments on this.
>>
>> Anyone have any experience using Scala with Struts2? I'm especially thinking
>> about s:iterate and scala.List.
>>
>> I've managed to use s:iterate with Scala's List like this:
>> <s:iterator value="%{getMyList().toArray().unbox(@java.lang.obj...@class)}"
>> status="status">
>> getMyList() returns a scala.List from my Scala-object, which I convert to an
>> JAVA-array using toArray().unbox().
>>
>> This seems very hackish and it would be cool if one could make a
>> "struts2-scala-plugin" which registered some kind of Iterator which the
>> IteratorComponent could use, refactoring out the call to
>> "MakeIterator.convert(findValue(value))" to a factory of some kind which
>> checked some kind of registry for providing a proper Iterator for the
>> Scala-object returned by findValue(value).
>>
>> Comments?
>
> For the curious;
> After some Googleing I "solved" this issue by defining a
> getListAsJavaIterator() method in my Scala-object which uses "implicit
> conversion" compiler-magic to define a new "iterator()" method on the
> Scala-Iterable Trait:
>
> object JavaIterableConversions {
>
> class JavaIterator[T](itr: Iterator[T]) extends java.util.Iterator[T] {
> def hasNext() = itr.hasNext
> def next() = itr.next
> def remove() = throw new
> java.lang.UnsupportedOperationException("Remove
> is not implemented in JavaIterableConversions:JavaIterator")
> }
>
> class JavaIterable[T](iterable: Iterable[T]) extends
> java.lang.Iterable[T] {
> def iterator() = new JavaIterator[T](iterable.elements)
> }
>
> implicit def implicitScalaIterableToJavaIterable[T](iterable :
> Iterable[T]): java.lang.Iterable[T] =
> new JavaIterable[T](iterable)
>
> }
>
> Usage:
>
> import JavaIterableConversions._
> class MyScalaClass {
> @BeanProperty
> var items: List[Item] = _
>
> def getListAsJavaIterator(): java.util.Iterator[_] = {
> items.iterator();
> }
> }
>
> Note: the iterator() *must* be defined in the same class as the
> implicit-conversion implicitScalaIterableToJavaIterable is defined/imported
> as it's the scala-compiler which does it's magic here. Trying to call
> items.iterator() from a JAVA-class will *not* work.
>
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René Gielen
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