java第三季6.5作业：对随机字符串List利用Collections.sort排序

package JavaSeason3.CollectionFramework;

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

/**
 * Created by Administrator on 2017/1/18.
 */
public class CollectionsTest {
    /**
     * 对int型List排序
     */
    public void testSort1(){
        List<Integer> integerList = new ArrayList<>();
        Random random = new Random();
        Integer k;
        for (int i = 0; i < 10; i++) {
            do {
                k = random.nextInt(100);
            }while (integerList.contains(k));
            integerList.add(k);
        }
        System.out.println("------------------排序前-----------------");
        for (Integer integer : integerList) {
            System.out.println("元素：" + integer);
        }
        Collections.sort(integerList);
        System.out.println("------------------排序后-----------------");
        for (Integer integer : integerList) {
            System.out.println("元素：" + integer);
        }
    }

    /**
     * 对String泛型的List进行排序
     */
    public void testSort2(){
        List<String> stringList = new ArrayList<>();
//        stringList.add("microsoft");
//        stringList.add("google");
//        stringList.add("lenovo");

        Random random = new Random();
        String s;
        for (int i = 0; i < 10; i++) {
            do {
                int length = random.nextInt(10);
                s = getRandomString(length);
            }while (stringList.contains(s));
            stringList.add(s);
        }

        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);
        }
    }

    /**
     * 获得给定长度的随机字符串
     */
    public static String getRandomString(int length){
        String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        Random random = new Random();
        StringBuffer sb = new StringBuffer();

        for(int i = 0 ; i < length; ++i){
            int number = random.nextInt(62);//[0,62)

            sb.append(str.charAt(number));
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        CollectionsTest ct = new CollectionsTest();
//        ct.testSort1();
        ct.testSort2();
    }
}

---

------------------排序前-----------------
元素：jeB
元素：4R
元素：waHX8v7li
元素：w
元素：FhJLBA
元素：J
元素：VNapr
元素：1d3EdvS
元素：obFmdjHi
元素：iyi8QG41
------------------排序后-----------------
元素：1d3EdvS
元素：4R
元素：FhJLBA
元素：J
元素：VNapr
元素：iyi8QG41
元素：jeB
元素：obFmdjHi
元素：w
元素：waHX8v7li

Process finished with exit code 0