Question

Do you know any way for safe copy cut operation in Android?

I want to make a file manager. I can do them with FileReader/Writer, but as is not safe (if app crashes), I want another safe way to do this.

Answer 1

You should probably design a fail-safe order of operations. For example (just making this up, haven’t validated it thoroughly):

1. Record in a persistent worklist file (/shared preference, etc) what you intend to do
2. Copy the file
3. Verify the copy is complete
4. Only then remove the original
5. Cleanup the record in the worklist

You should not do the work on the UI thread. You may want to consider doing it in a service to handle the case of huge files (or large numbers of files) which may take a while.

You may also want to consider if you can in some cases use the File.renameTo() method – this would require that the source and destination be on the same partition (ie, both on external storage). Also you would have to make sure that the destination directory exists.

Also put some thought into what you are going to do if the selected object is a directory rather than a file…