> List <Integer> aList = Arrays.asList( new int [] { 1, 3, 5 });

You can drop the inner array, asList takes variable number of arguments.

> // I need to check if Java 8 has map literals a la Groovy...

Sadly not, IIRC they've backed off from literals towards a Guava style static factory methods, which I'm not thrilled about.

> I'm not seeing that much of a difference in parameter passing, other than the explicit reference/dereference syntax.

So let's say I'm a newbie Perl developer just exploring subs.

  sub stuff {
      my ($a, $b) = @_;
      print "$a and $b\n";
  }

  my $a = 1;
  my $b = 2;

  stuff($a, $b);

It works! Hurrah. Feeling clever, I move onto collections.

  sub stuff {
      my (@a, %b) = @_;
      print "$a[0] and $b{A}\n";
  }

  my @a = (1);
  my %b = (A => 2);

  stuff(@a, %b);

And it doesn't work at all. @a has some additional values, and %b is undef.

So yes, let's use references.

  sub stuff {
      my ($a, $b) = @_;
      print "${$a}[0] and ${$b}{A}\n";
  }

  my @a = (1);
  my %b = (A => 2);

  stuff(\@a, \%b);

Except now, I have two ways of working with Perl's collections, two separate sets of sigils, and all because I wanted to pass two collections into a function and Perl treats function arguments as a collection, and Perl implicitly flattens collections.

The difference I see, as a Perl newbie only working with it out of necessity, is that having (because you need it because of earlier design choices) more than one way of operating on data structures, violates the principle of least surprise.