I implemented in a basic way.

    Comparator<Student> com=new Comparator<Student>()
    {
        public int compare(Student s1, Student s2){
            if(s1.getCgpa()>s2.getCgpa())
                return -1;
            else if(s1.getCgpa()<s2.getCgpa())
                return 1;
            else{
                if(s1.getFname().compareTo(s2.getFname())>0)
                    return 1;
                else
                    return -1 ;   
            }        
        }
    };

    Collections.sort(studentList, com);