java 实现Comparator接口排序

public class TeacherComparator implements Comparator<Teacher> {
    @Override
    public int compare(Teacher o1, Teacher o2) {
        // TODO Auto-generated method stub
        if (o1.getAge() > o2.getAge())
            return -1; // 由高到低
        else if (o1.getAge() < o2.getAge())
            return 1;
        else {
            if (o1.getName() > o2.getName())
                return 1; // 由低到高
            else if (o1.getAge() < o2.getAge())
                return -1;
            else
                return 0;
        }
    }
}

public class Teacher {

    private int name;
    private int age;

    public Teacher() {
    }

    public Teacher(int name, int age) {
        this.name = name;
        this.age = age;
    }

    public int getName() {
        return name;
    }

    public void setName(int name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public static void main(String[] args) {
        Set<Teacher> set = new TreeSet<Teacher>(new TeacherComparator());
        set.add(new Teacher(10, 15));
        set.add(new Teacher(30, 15));
        set.add(new Teacher(20, 30));
        set.add(new Teacher(10, 20));
        set.add(new Teacher(80, 20));
        Iterator<Teacher> it = set.iterator();
        while (it.hasNext()) {
            Teacher customer = it.next();
            System.out.println(customer.getName() + " " + customer.getAge());
        }
    }
}

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20 30
10 20
80 20
10 15
30 15