public class CollectionsTest {    public static void main(String[] args) {        List
    
      list = new ArrayList
     
      ();        list.add(34);        list.add(55);        list.add(56);        list.add(89);        list.add(12);        list.add(23);        list.add(126);        System.out.println(list);        //对集合进行排序        Collections.sort(list);        System.out.println(list);        //对集合进行随机排序        Collections.shuffle(list);        System.out.println(list);        //获取集合最大值、最小值        int max = Collections.max(list);        int min = Collections.min(list);        System.out.println("Max:" + max + " Min: " + min);        List
      
        list2 = Arrays.asList("Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday".split(","));        System.out.println(list2);        //查找集合指定元素，返回元素所在索引        //若元素不存在，n表示该元素最有可能存在的位置索引        int index1 = Collections.binarySearch(list2, "Thursday");        int index2 = Collections.binarySearch(list2, "TTTTTT");        System.out.println(index1);        int n = -index2 - 1;        //查找子串在集合中首次出现的位置        List
       
         subList = Arrays.asList("Friday,Saturday".split(","));        int index3 = Collections.indexOfSubList(list2, subList);        System.out.println(index3);        int index4 = Collections.lastIndexOfSubList(list2, subList);        System.out.println(index4);        //替换集合中指定的元素，若元素存在返回true，否则返回false        boolean flag = Collections.replaceAll(list2, "Sunday", "tttttt");        System.out.println(flag);        System.out.println(list2);        //反转集合中的元素的顺序        Collections.reverse(list2);        System.out.println(list2);        //集合中的元素向后移动k位置，后面的元素出现在集合开始的位置        Collections.rotate(list2, 3);        System.out.println(list2);        //将集合list3中的元素复制到list2中，并覆盖相应索引位置的元素        List
        
          list3 = Arrays.asList("copy1,copy2,copy3".split(","));        Collections.copy(list2, list3);        System.out.println(list2);        //交换集合中指定元素的位置        Collections.swap(list2, 0, 3);        System.out.println(list2);        //替换集合中的所有元素，用对象object        Collections.fill(list2, "替换");        System.out.println(list2);        //生成一个指定大小与内容的集合        List
         
           list4 = Collections.nCopies(5, "哈哈"); System.out.println(list4); //为集合生成一个Enumeration List
          
            list5 = Arrays.asList("I love my country!".split(" ")); System.out.println(list5); Enumeration
           
             e = Collections.enumeration(list5); while (e.hasMoreElements()) { System.out.println(e.nextElement()); } }}