Question

I know how to separate the string to string[]. In my project, I use t = time.split("-") to split a time into a string array t, and t[0]=DD, t[1]=MM. Now I need to convert the string array t into string time with format DD-MM. Did java have functions for that?

Answer 1

Guava does:

String joined = Joiner.on('-').join(parts);

On the other hand, I’d actually suggest not splitting and joining your string to start with. Instead, parse it into an appropriate date/time type (ideally Joda Time), perform any manipulation you need, and then reformat it using a different format pattern.

This will improve your error detection, and basically make your code really reflect the nature of the data you’re working with – instead of just talking about splitting and joining text.