How can I change the date format in Java? [duplicate]

Answer 1

This is just Christopher Parker's answer adapted to use the new¹ classes from Java 8:

final DateTimeFormatter OLD_FORMATTER = DateTimeFormatter.ofPattern("dd/MM/yyyy");
final DateTimeFormatter NEW_FORMATTER = DateTimeFormatter.ofPattern("yyyy/MM/dd");

String oldString = "26/07/2017";
LocalDate date = LocalDate.parse(oldString, OLD_FORMATTER);
String newString = date.format(NEW_FORMATTER);

1 well, not that new anymore, Java 9 should be released soon.