一文讲解Java中初始化List集合的8种方式（附代码）

List list = new ArrayList<>(); list.add("1"); list.add("2"); list.add("3"); System.out.println("getList1: " + list);

getList1: [1, 2, 3]

// 生成的list不可变 List list = Arrays.asList("1", "2", "3"); System.out.println("getList2: " + list); // 如果要可变需要用ArrayList包装一下 List numbers = new ArrayList<>(Arrays.asList("1", "2", "3")); numbers.add("4"); System.out.println("numbers: " + numbers);

getList2: [1, 2, 3] numbers: [1, 2, 3, 4]

// 生成的list不可变 List list = Collections.nCopies(3, "1"); System.out.println("getList3: " + list); // 如果要可变需要用ArrayList包装一下 List dogs = new ArrayList<>(Collections.nCopies(3, "dog")); dogs.add("dog"); System.out.println("dogs: " + dogs);

getList3: [1, 1, 1] dogs: [dog, dog, dog, dog]

List list = Lists.newArrayList("1", "2", "3"); System.out.println("getList4: " + list);

getList4: [1, 2, 3]

List list = new ArrayList() {{ add("1"); add("2"); add("3"); }}; System.out.println("getList5: " + list);

getList5: [1, 2, 3]

List list = ImmutableList.of("1", "2", "3"); System.out.println("getList6: " + list);

getList6: [1, 2, 3]

List list = Stream.of("1", "2", "3").collect(Collectors.toList()); System.out.println("getList7: " + list);

getList7: [1, 2, 3]

List list = List.of{"1", "2", "3"}; System.out.println("getList8: " + list);

getList8: [1, 2, 3]