abc value:2
key:abcd value:1
我们可以看到testCount1和testCount2执行结果相同,仅仅一行代码:Map countMap = list.stream...List list = Lists.newArrayList("1", "2", "3", "4", "5", "6");
List collect1 = list.stream...//结果:[1, 2, 3, 4, 5, 6]
System.out.println(collect1);
//结果:111111
list.stream...:[[a, b, c], [d, e, f], [j, k, y]]
System.out.println(list);
List collect = list.stream...().collect(Collectors.toSet());
System.out.println(collect2);
String collect3 = list.stream