Collection类及常用API
Collection—类集工具类，定义了若干用于类集和映射的算法，这些算法被定义为静态方法，具体查看api文档;
a) public static void sort(List<T> liet)
b) public static int binarySearch(List<T> list,T key)
c) public static void reverse(List<?> list)
d) public static void shuffle(List<?> list)
e) public static void swap(List<?> list,int i,int j)
f) public static <T> void fill(List<? super T> list,T obj)
1 List<String> nList=new ArrayList<String>();
2 nList.add("zhangsan");
3 nList.add("lisi");
4 nList.add("wangwu");
5 nList.add("zhaoliu");
6 nList.add("tianqi");
7 System.out.println("操作前");
8 for(String s:nList){
9 System.out.print(s+" ");
10 }
11
12 System.out.println();
13 System.out.println("交换顺序后");
14 Collections.swap(nList,1,2);
15 for(String s:nList){
16 System.out.print(s+" ");
17 }
18
19 System.out.println();
20 System.out.println("自然排序后");
21 Collections.sort(nList);
22 for(String s:nList){
23 System.out.print(s+" ");
24 }
25
26 System.out.println();
27 System.out.println("二分法查找");
28 System.out.println(Collections.binarySearch(nList, "zhaoliu"));
29
30 System.out.println("打乱顺序");
31 Collections.shuffle(nList);
32 for(String s:nList){
33 System.out.print(s+" ");
34 }
35
36 System.out.println();
37 System.out.println("填充");
38 Collections.fill(nList, "jay");
39 for(String s:nList){
40 System.out.print(s+" ");
41 }
输出结果：
操作前
zhangsan lisi wangwu zhaoliu tianqi
交换顺序后
zhangsan wangwu lisi zhaoliu tianqi
自然排序后
lisi tianqi wangwu zhangsan zhaoliu
二分法查找
4
打乱顺序
zhaoliu tianqi wangwu zhangsan lisi
填充
jay jay jay jay jay