How to parse case-insensitive strings with jsr310 DateTimeFormatter?

问题

jsr-310 has a handy class DateTimeFormatters which allows you to construct a DateTimeFormatter. I particularly like the pattern(String) method - see javadoc

However, I hit a problem whereby this is case sensitive -- e.g.

DateTimeFormatters.pattern(\"dd-MMM-yyyy\");

matches with \"01-Jan-2012\", but not with \"01-JAN-2012\" or \"01-jan-2012\".

One approach would be to break the string down and parse components, or another would be to use Regex to replace the case-insensitive strings with the case-sensitive string.

But it feels like there ought to be an easier way...

回答1:

And there is... according to the User Guide (offline, see JavaDoc instead), you should use DateTimeFormatterBuilder to build a complex DateTimeFormatter

e.g.

DateTimeFormatterBuilder builder = new DateTimeFormatterBuilder();
builder.parseCaseInsensitive();
builder.appendPattern("dd-MMM-yyyy");
DateTimeFormatter dateFormat = builder.toFormatter();

回答2:

This alternative is usefull for initializating static variables:

DateTimeFormatter myFormatter = new DateTimeFormatterBuilder()
                               .parseCaseInsensitive()
                               .appendPattern("dd-MMM-yyyy")
                               .toFormatter(Locale.ENGLISH);

回答3:

Just an extra Note, the order matters.

This is case insensitive:

            DateTimeFormatter format = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .parseLenient()
                .appendPattern("HH:mm EEEE")
                .toFormatter();

This is not:

            DateTimeFormatter format = new DateTimeFormatterBuilder()
                .appendPattern("HH:mm EEEE")
                .parseCaseInsensitive()
                .parseLenient()
                .toFormatter();

来源：https://stackoverflow.com/questions/10797808/how-to-parse-case-insensitive-strings-with-jsr310-datetimeformatter

标签

java

jsr310