How to sort ArrayList using Comparator? [duplicate]

Answer 1

Use Collections.sort():

Collections.sort(students, getCompByName());

Note: might be useful to make your comparator a private static final variable.

Note 2: modifies the list in place; does not create a new list.

Answer 2

Use the Collections.sort(List, Comparator) method:

Collections.sort(students, Student.getCompByName());

Also in your code it would be good to use the List interface when declaring the List:

List<Student> students = new ArrayList();

You could also tighten up the code by using a Student[] and passing it to the ArrayList constructor:

public static void main(String[] args) {
    Student[] studentArr = new Student[]{new Student("Mike"),new Student("Hector"), new Student("Reggie"),new Student("zark")};
    List<Student> students = new ArrayList<Student>(Arrays.asList(studentArr));
    Collections.sort(students, Student.getCompByName());

    for(Student student:students){
        System.out.println(student.getName());
    }
}

Here is a Gist of the full source.