Android : How to remove references when using List in android

I'm having a trouble with using List in java.

I created a list of objects called A, then I create other list called "B", I assign A to B.

But if I use A.clear() then B also cleared:

Example:

    List<String> original = new ArrayList<String>();

    original.add("Test");

    List<String> copy = new ArrayList<String>();

    original.clear();

--> Is there any way to maintain value of B even thought A is cleared?