Dùng comparator sắp xếp Object theo thuộc tính

Main

//Class Main
public class Test {
    public static void main(String[] args) {
        Nguoi n1 = new Nguoi("A");
        Nguoi n2 = new Nguoi("C");
        Nguoi n3 = new Nguoi("B");
        Nguoi[] n = new Nguoi[3];
        n[0] = n1;
        n[1] = n2;
        n[2] = n3;
        Arrays.sort(n,new SortByName());
        for (Nguoi nguoi : n) {
            System.out.println(nguoi.getTen());
        }

    }

Nguoi.java

//Class Nguoi:
Class Nguoi{
    String ten;
    public String getTen(){
        return this.ten;
    }
}

SortByName.java

public class SortByName implements Comparator<Nguoi> {
// Ham compare se dinh nghia cach so sanh, 
//sau do dung no de truyen vao ham Collections.sort(list,CachSX);

// Neu bang nhau thi return 0
// Neu o1 hon o2 thi return 1 so lon hon 0 (Thuong dung 1)
// Neu o1 nho hon o2 thi return 1 so nho hon 0( Thuong la -1)
    @Override
    public int compare(Nguoi o1, Nguoi o2) {
        int resurl;
        resurl = o1.getTen().compareTo(o2.getTen());
        return resurl;
    }
}

SortByNameCach2.java

// Cach 2 la khong can tao class SortByName ma khai bao 1 doi tuong Comparator luon roi override lai:
    public void sortPeople() {
        Collections.sort(list, new Comparator<Student>() {
            @Override
            public int compare(Nguoi n1, Nguoi n2) {
                return n1.getName().compareTo(n2.getName());
            }
        });
    }