Java - Date format for Multiple Scenarios

Question

I have a java component to format the date that I retrieve. Here is my code:

    Format formatter      = new SimpleDateFormat(\"yyyyMMdd\");
        String s = \         


        

Answer 1

In case of you have optional parts in pattern you can use [ and ].

For example

public static Instant toInstant(final String timeStr){
    final DateTimeFormatter formatter = DateTimeFormatter
            .ofPattern("yyyy-MM-dd HH[:mm[:ss[ SSSSSSSS]]]")
            .withZone(ZoneId.of("UTC"));
    try {
        return Instant.from(formatter.parse(timeStr));
    }catch (DateTimeException e){
        final DateTimeFormatter formatter2 = DateTimeFormatter
                .ofPattern("yyyy-MM-dd")
                .withZone(ZoneId.of("UTC"));
        return LocalDate.parse(timeStr, formatter2).atStartOfDay().atZone(ZoneId.of("UTC")).toInstant();
    }
}

cover

• yyyy-MM-dd
• yyyy-MM-dd HH
• yyyy-MM-dd HH:mm
• yyyy-MM-dd HH:mm:ss
• yyyy-MM-dd HH:mm:ss SSSSSSSS