import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Random;

/*

?* 1.創建完List<string>之后，往其中添加十條隨機字符串

?* 2.每條字符串的長度為10以內的隨機整數

?* 3.每條字符串的每個字符都為隨機生成的字符，字符可以重復

?* 4.每條隨機字符串不可重復

?*/

public class ExceciseCollections {

List<String> stringList=new ArrayList<String>();

public void testSort() {

String a="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

Random random=new Random();

for(int i=0;i<10;i++) {

StringBuilder sb=new StringBuilder();

do {

sb.delete(0, sb.length());

int strlen=random.nextInt(10)+1;

if(strlen==0)continue;

for(int k=0;k<=strlen;k++) {

int cursor=random.nextInt(a.length());

sb.append(a.charAt(cursor));

}

}while(stringList.contains(sb.toString()));

stringList.add(sb.toString());

}

System.out.println("---------排序前------------");

for(String str:stringList) {

System.out.println("序列"+str);

}

Collections.sort(stringList);

System.out.println("-----排序后----------");

for(String str:stringList) {

System.out.println("序列"+str);

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

ExceciseCollections ec=new ExceciseCollections();

ec.testSort();

}

}