java中ArrayList的两种排序方法实例

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;
public class compre {
 
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan=new Scanner(System.in);
		int n;
		ArrayList al=new ArrayList();
		System.out.println("请输入需要的个数");
		n=scan.nextInt();
		System.out.println("请逐一输入");
		for(int i=0;i<n;i++) {
			al.add(i,scan.nextInt());
		}
		System.out.println("你输入的数字是：");
		for(int i=0;i<al.size();i++) {
			int temp=(int)al.get(i);
			System.out.print(temp+" ");
		}
		Collections.sort(al);//针对一个ArrayList内部的数据排序
		System.out.println();
		System.out.println("经过排序后：");
		for(int i=0;i<al.size();i++) {
			int temp=(int)al.get(i);
			System.out.print(temp+" ");
		}
	}
}

 class SortByName implements Comparator {
         public int compare(Object o1, Object o2) {
          Student s1 = (Student) o1;
          Student s2 = (Student) o2;
          return s1.getName().compareTo(s2.getName());
         }
}

  class SortByAge implements Comparator {
         public int compare(Object o1, Object o2) {
          Student s1 = (Student) o1;
          Student s2 = (Student) o2;
          return s1.getAge().compareTo(s2.getAge());
//          if (s1.getAge() > s2.getAge())
//           return 1;
//          return -1;
         }
        }