Question

Is there any way to perform SQL Like Queries or Filtering on Java Data Structures?

I want to filter objects in an ArrayList and a HashMap by fields of the objects contained within.

Answer 1

You might like Quaere, which is a fairly rich query language for java object graphs:

Integer[] numbers={5, 4, 1, 3, 9, 8, 7, 2, 0};
Iterable<Integer> lowNumbers=
    from("n").in(numbers).
    where(lt("n",5).
    select("n");