import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class Test {

    public static void main(String[] args) {

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

        list.add("c");

        list.add("b");

        list.add("d");

        list.add("a");

        System.out.println(list);//[c, b, d, a]

        Collections.sort(list);//对list集合进行排序

        System.out.println(list);//[a, b, c, d]

    }

}

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class Test2 {

    public static void main(String[] args) {

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

        list.add("caa");

        list.add("cab");

        list.add("daa");

        list.add("add");

        System.out.println(list);//[caa, cab, daa, add]

        Collections.sort(list);//对list集合进行排序

        System.out.println(list);//[add, caa, cab, daa]

    }

}