作业！！！

public void testSort2() {

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

Random random=new Random();

String st = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

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

StringBuilder string1=new StringBuilder();

do {

int length=random.nextInt(10);

for(int j=0;j<((length==0)?1:length);j++){

int index = random.nextInt(st.length());

string1.append(st.charAt(index));

}

}while(sl.contains(string1));

sl.add(string1.toString());

}

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

for (String string : sl) {

System.out.println("字符串元素："+string);

}

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

Collections.sort(sl);

for (String string : sl) {

System.out.println("字符串元素："+string);

}

}