[Eranga]

A simple way I used to test this. See you can get the logic for your application.

Code:

    public static void main(String[] args) {
        // TODO code application logic here
        ArrayList list1 = new ArrayList();
        list1.add("a1");
        list1.add("a2");
        list1.add("a3");
        
        ArrayList list2 = new ArrayList();
        list2.add("b1");
        list2.add("a2");
        list2.add("a3");
        
        for (int i = 0; i < list1.size(); i++){
        String str1 = (String) list1.get(i);
            for (int j = 0; j < list2.size(); j++){
                String str2 = (String) list2.get(j);
                int result = str1.compareTo(str2);
                if (result == 0) 
                    System.out.println(str1+  " = " + str2);
                else if (result > 0) 
                    System.out.println(str1+  " > " + str2);
                else if (result < 0) 
                    System.out.println(str1+  " < " + str2);
            }
        }
    }