CSV文件解析问题：与Excel不同的时间格式（使用Java）

Question

我试图从一个csv文件（excel）中读取和解析时间，但由于excel的移除前导零的特性，时间有不同的格式。像这样：

1/1/2021,9:05:28
1/1/2021,2:48:32
1/1/2021,15:11:00
2/1/2021,14:37:38

09:05:28这样的时间在Excel中变成了9:05:28，不能和14:37:38格式一起解析。

ArrayList<className> list = new ArrayList<>();

List<String> lines = Files.readAllLines(Paths.get("file.csv"));
for (int i = 0; i < lines.size(); i++) {
    String[] elements = lines.get(i).split(",");
    // Read data from file
    LocalDate date = LocalDate.parse(elements[0]);
    LocalTime time = LocalTime.parse(elements[1]);
    list.add(new className(date, time));
}
        

提前道谢。

Answer 1

您可以在DateTimeFormatterBuilder对象上使用多种格式，如下所示。

java prettyprint-override">private static void dateSample() throws IOException {
        ArrayList<TimeDataCsv> list = new ArrayList<>();
        DateTimeFormatter dateOnlyFormatter = new DateTimeFormatterBuilder()
                .appendOptional(DateTimeFormatter.ofPattern("d/M/yyyy"))
                .appendOptional(DateTimeFormatter.ofPattern("d/MM/yyyy"))
                .appendOptional(DateTimeFormatter.ofPattern("dd/M/yyyy"))
                .appendOptional(DateTimeFormatter.ofPattern("dd/MM/yyyy"))
                .toFormatter();

        DateTimeFormatter timeOnlyFormatter = new DateTimeFormatterBuilder()
                .appendOptional(DateTimeFormatter.ofPattern("H:mm:ss"))
                .appendOptional(DateTimeFormatter.ofPattern("HH:mm:ss"))
                .toFormatter();
        List<String> lines = Files.readAllLines(Paths.get("sample.csv"));
        for (int i = 0; i < lines.size(); i++) {
            String[] elements = lines.get(i).split(",");
            String dateString = elements[0].trim();
            String timeString = elements[1].trim();
            LocalDate date = LocalDate.parse(dateString, dateOnlyFormatter);
            LocalTime time = LocalTime.parse(timeString, timeOnlyFormatter);
            list.add(new TimeDataCsv(LocalDateTime.of(date, time)));
        }        
    }

    public static class TimeDataCsv {
        public LocalDate date;
        public LocalTime time;
        public LocalDateTime dateTime;

        public TimeDataCsv(LocalDate date, LocalTime time) {
            this.date = date;
            this.time = time;
        }

        public TimeDataCsv(LocalDateTime dateTime) {
            this.dateTime = dateTime;
        }
    }
}