package?com.imooc.collection;

import?java.util.ArrayList;
import?java.util.Collections;
import?java.util.List;
import?java.util.Random;

public?class?Exercise?{

	public?void?test(){
		List<String>stringList=new?ArrayList<String>();
????????String?s="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

????????char?b;
????????Random?r=new?Random();
????????for(int?i=0;i<10;i++){
????????????String?a="";
????????	do{int?j=r.nextInt(10);
????????	for(int?z=0;z<j;z++){
????????		b=s.charAt(r.nextInt(61));
????????		a=a+b;
????????	}}while(stringList.contains(a));
???stringList.add(a);
???System.out.println("添加了元素："+a);
????????}
???System.out.println("---------------排序前---------------");
????for?(String?string?:?stringList)?{
		System.out.println("元素："+string);
	}
????Collections.sort(stringList);
????System.out.println("---------------排序后--------------");
????for?(String?string?:?stringList)?{
????	System.out.println("元素："+string);
	}
	}
	public?static?void?main(String[]?args)?{
		//?TODO?Auto-generated?method?stub
Exercise?e=new?Exercise();
e.test();
	}

}

希望大家能指出不足的地方！