public void sortRandomString(){

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

String str;

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

//隨機生成數字或字母并添加到str

do{

str="";

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

int j = (int) (Math.random() * 3 + 1);

switch (j) {

case 1:

// 生成隨機數字

int k = (int) (Math.random() * 10);

str += k;

break;

case 2:

// 生成隨機大寫字母

int m = (int) (65 + Math.random() * 26);

str += (char) m;

break;

case 3:

// 生成隨機小寫字母

int n = (int) (97 + Math.random() * 26);

str += (char) n;

break;

}

if(Math.random()<0.1)

break;

}

}while(stringList.contains(str));

stringList.add(str);

System.out.println("List中添加了字符串："+str);

}

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

for (String string : stringList) {

System.out.println(("元素："+string));

}

Collections.sort(stringList);

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

for (String string : stringList) {

System.out.println(("元素："+string));

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

CollectionsTest ct = new CollectionsTest();

ct.sortRandomString();

}

}