将逗号分隔值转换为List <Long>

Question

假设我有一组像1,2,3,4,5,6,7输入一样的数字String.我想将这些数字转换List为Long对象,即List<Long>.

任何人都可以推荐最简单的方法吗？

Answer 1

你的意思是这样的？

String numbers = "1,2,3,4,5,6,7";

List<Long> list = new ArrayList<Long>();
for (String s : numbers.split(","))
    list.add(Long.parseLong(s));

System.out.println(list);

从Java 8开始,您可以将其重写为

List<Long> list = Stream.of(numbers.split(","))
        .map(Long::parseLong)
        .collect(Collectors.toList());

如果你想得到更短的版本 List<String>

List<String> fixedSizeList = Arrays.asList(numbers.split(","));
List<String> rezisableList = new ArrayList<>(fixedSizeList);

或在线

List<String> list = new ArrayList<>(Arrays.asList(numbers.split(",")));

Answer 2

使用java-8的简单方便的解决方案(为了完成线程):

String str = "1,2,3,4,5,6,7";
List<Long> list = Arrays.stream(str.split(",")).map(Long::parseLong).collect(Collectors.toList());

System.out.println(list);

[1,2,3,4,5,6,7]

更好的是,使用Pattern.splitAsStream():

Pattern.compile(",").splitAsStream(str).map(Long::parseLong).collect(Collectors??.toList());

Answer 3

我会使用优秀的谷歌番石榴库来做到这一点。String.split 会引起很多麻烦。

String numbers="1,2,3,4,5,6,7";
Iterable<String> splitIterator = Splitter.on(',').split(numbers);
List<String> list= Lists.newArrayList(splitIterator );