Set_advanced_project/Collection_module/src/Collections_package/Collections_demo1.java

package Collections_package;

import java.util.ArrayList;
import java.util.Collections;

public class Collections_demo1 {
    public static void main(String[] args) {
        /*
            public static <T> boolean addAll (Collection<T> c, T...elements)    批量添加元素
            public static void shuffle (List<?> list)                           打乱List集合元素的顺序
         */

        //addAll  批量添加元素

        //1、创建集合对象
        ArrayList<String> list=new ArrayList<>();

        //2、批量添加元素
        Collections.addAll(list,"abc","abc","bcd","edf","asdf");

        //3、打印集合
        System.out.println(list);

        //4、shuffle 打乱
        Collections.shuffle(list);
        System.out.println(list);
    }
}