实例化list
1 JDK2:
List<String> list = Arrays.asList("one", "two", "three");
2 JDK7
List<String> list = new ArrayList<>(); list.add("one");
list.add("two");
list.add("three");
3 JDK8
List<String> list = Stream.of("one", "two", "three").collect(Collectors.toList());
4 JDK9
//不可变List
List immutableList = List.of("one", "two", "three");
//可变List可以通过构造函数复制不可变List
List mutableList = new ArrayList<>(List.of("one", "two", "three"));
