How to parse case-insensitive strings with JSR-310 DateTimeFormatter?

java, jsr310

Solution

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();

Problem

JSR-310 has a handy class `DateTimeFormatter` 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...

Original source