Blocking/synchronous version of Files.copy

Question

I'm trying to copy a file from one directory to another, but I want the call to be blocking so that the program only proceeds execution once the whole file has been transferred.

Currently I'm using Files.copy(), which uses non-blocking IO and returns instantly. What other options (preferably built into the java standard library) do I have to solve this problem?

Many thanks, Gareth

Answer 1

Files.copy isn't asynchronous, it doesn't return until the copy is complete.

Normally if a method is asynchronous, the JavaDoc will be very clear about that, and the method will accept some form of callback (a lambda, or an object implementing an interface with a method it'll call, etc.), or return something that can be used to check for completion (or error). Files.copy doesn't do that, and its Javadoc doesn't say it's asynchronous, so there's no reason to suspect it is. (I just did a quick test to be sure, and it didn't return until the copy was complete.)