perf comparison

    public static void main(String[] args) throws Exception {
        int size = 10000000;
        Vector<String> v = new Vector<String>(size);
        ArrayList<String> a = new ArrayList<String>(size);
        long a0 = System.nanoTime();
        for(int i = 0; i < size; i++){
            v.add("ASDF");
        }
        long a1 = System.nanoTime();
        for(int i = 0; i < size; i++){
            a.add("ASDF");
        }
        long a2 = System.nanoTime();
        System.out.println("a1-a0:" + (a1-a0));
        System.out.println("a2-a1:" + (a2-a1));
    }
//output:
/*
a1-a0:258077209
a2-a1:76019664
*/