Collections.sort的两种用法

http://gwh-08.iteye.com/blog/1233401/

class Foo implements Comparable<Foo>{

    @Override
    public int compareTo(ClientPortalButton o) {
        return this.i.compareTo(o.getI());
    }

}

学习了：http://blog.csdn.net/veryisjava/article/details/51675036

可以使用匿名类直接进行排序

public static void main(String[] args) {
        List<Students> students = new ArrayList<Students>();
        students.add(new Students(23, 100));
        students.add(new Students(27, 98));
        students.add(new Students(29, 99));
        students.add(new Students(29, 98));
        students.add(new Students(22, 89));
        Collections.sort(students, new Comparator<Students>() {  

            @Override
            public int compare(Students o1, Students o2) {
                int i = o1.getScore() - o2.getScore();
                if(i == 0){
                    return o1.getAge() - o2.getAge();
                }
                return i;
            }
        });
        for(Students stu : students){
            System.out.println("score:" + stu.getScore() + ":age" + stu.getAge());
        }
}