Convert string to OffsetDateTime in Java

OffsetDateTime represents a date-time with an offset , for eg.

2007-12-03T10:15:30+01:00

The text you are trying to parse does not conform to the requirements of OffsetDateTime. See https://docs.oracle.com/javase/8/docs/api/java/time/OffsetDateTime.html

The string being parsed neither contains the ZoneOffset nor time. From the string and the pattern of the formatter, it looks like you just need a LocalDate. So, you could use :

LocalDate.parse("20150101", DateTimeFormatter.ofPattern("yyyyMMdd"));

Thanks everyone for your reply. Earlier I was using joda datetime (look at below method) to handle date and datetime both but I wanted to use Java8 libraries instead of the external libraries.

static public DateTime convertStringInDateFormat(String date, String dateFormat){
    DateTimeFormatter formatter = DateTimeFormat.forPattern(dateFormat);
return formatter.parseDateTime(date);
}

I was expecting same with OffsetDateTime but got to know we can use ZonedDateTime or OffsetDateTime if we want to work with a date/time in a certain time zone. As I am working on Period and Duration for which LocalDate can help.

String to DateTime:

LocalDate date =
LocalDate.parse("20150101", DateTimeFormatter.ofPattern("yyyyMMdd"));

LocalDate to desired string format:

String dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'";
date.atStartOfDay().format(DateTimeFormatter.ofPattern(dateFormat));

Use a LocalDate instead of offsetDatetime for your case as you want to parse only date (no time/offset). The usage of offsetDatetime is very well discussed here