Collections方法的使用

public static void main(String[] args) {// 0、给List排序List<Integer> list = new ArrayList<Integer>();int array[] = { 6, 3, 4, 9, 0, 2, 5, 7, 1, 8 };for (int i = 0; i < array.length; i++) {list.add(new Integer(array[i]));}System.out.println("排序前:");System.out.println(list);System.out.println("排序后：");Collections.sort(list);System.out.println(list);System.out.println("==================================");// 1、打乱List的顺序List<Integer> list1 = new ArrayList<Integer>();for (int i = 0; i < 10; i++) {list1.add(new Integer(i));}System.out.println("打乱前:");System.out.println(list1);System.out.println("打乱后：");Collections.shuffle(list1);// 打乱ListSystem.out.println(list1);System.out.println("==================================");// 2、倒序排列ListList<Integer> list2 = new ArrayList<Integer>();for (int i = 0; i < 10; i++) {list2.add(new Integer(i));}System.out.println("倒叙前:");System.out.println(list2);System.out.println("倒叙后：");Collections.reverse(list2);// 倒序排列ListSystem.out.println(list2);System.out.println("==================================");// 3、使用指定元素替换指定列表中的所有元素。List<String> list3 = new ArrayList<String>();String str[] = { "dd", "aa", "bb", "cc", "ee" };for (int j = 0; j < str.length; j++) {list3.add(new String(str[j]));}System.out.println("替换前:");System.out.println(list3);System.out.println("替换后：");Collections.fill(list3, "gg");System.out.println(list3);System.out.println("==================================");// 4、返回给定 collection 的最小元素和最大元素List<Integer> list4 = new ArrayList<Integer>();int arr[] = { 6, 3, 4, 9, 0, 2, 5, 7, 1, 8 };for (int i = 0; i < arr.length; i++) {list4.add(new Integer(arr[i]));}System.out.println("集合内容为:");System.out.println(list4);System.out.println("集合中最小值为：" + Collections.min(list4));System.out.println("集合中最大值为：" + Collections.max(list4));System.out.println("==================================");// 5、用两个参数，一个目标 listTarget 和一个源 listSrc， 将源的元素拷贝到目标，并覆盖它的内容。目标 List// 至少与源一样长。如果它更长，则在目标 List 中的剩余元素不受影响。int shuzu1[] = { 111, 222, 333, 444, 555 };List<Integer> listTarget = new ArrayList<>();for (int i = 0; i < shuzu1.length; i++) {listTarget.add(new Integer(shuzu1[i]));}System.out.println("目标集合被覆盖前:");System.out.println(listTarget);int shuzu2[] = { 666, 777 };List<Integer> listSrc = new ArrayList<>();for (int j = 0; j < shuzu2.length; j++) {listSrc.add(new Integer(shuzu2[j]));}System.out.println("目标集合被覆盖后:");Collections.copy(listTarget, listSrc);/// 后面一个参数是目标列表 ，前一个是源列表System.out.println(listTarget);System.out.println("==================================");}排序前:[6, 3, 4, 9, 0, 2, 5, 7, 1, 8]排序后：[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]==================================打乱前:[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]打乱后：[3, 0, 5, 7, 8, 1, 6, 4, 2, 9]==================================倒叙前:[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]倒叙后：[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]==================================替换前:[dd, aa, bb, cc, ee]替换后：[gg, gg, gg, gg, gg]==================================集合内容为:[6, 3, 4, 9, 0, 2, 5, 7, 1, 8]集合中最小值为：0集合中最大值为：9==================================目标集合被覆盖前:[111, 222, 333, 444, 555]目标集合被覆盖后:[666, 777, 333, 444, 555]==================================