作業(yè)隨機(jī)字符串排序
package imooc_collection_map_demo;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;
public class CollectionsTest {
???? public static void main(String[] args) {
???????? List<String> stringList = new ArrayList<String>();
???????? Random random = new Random();
???????? String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
????????
???????? for(int i = 0; i<10; i++){
???????????? int len = random.nextInt(10) + 1; //長度
???????????? int index;
???????????? StringBuffer sb = new StringBuffer();
???????????? do{
???????????????? for (int j = 0; j<len; j++){
???????????????????? index = random.nextInt(62); //下表
???????????????????? sb.append(str.charAt(index));
???????????????? }
???????????? }while(stringList.contains(sb.toString()));
???????????? stringList.add(sb.toString());
???????? }
???????? System.out.println("排序前: " + stringList);
???????? Collections.sort(stringList);
???????? System.out.println("排序后: " + stringList);
???? }
}