java - How do I only download new files from a server?

Question

I have a number of CSV files that I want to download from Yahoo finance each day. I want my application to read the file's creation date (on my computer, not the server). If the creation date is prior to today then the new file should be downloaded (as it will have new data). If not then the new file should not be downloaded, and the correlation calculator (which is essentially what my application is), should use the last downloaded file for the particular stock code.

I have done some googling and have found the Apache POI project.

Is this the best way to go, is there a better way, what would you recommend. Is JNI at all relevant here?

Answer 1

I might be missing something but I can't see why you would need JNI or POI to download a file. If you are downloading the file with HTTP, you can use an HttpURLConnection with the "If-Modified-Since" request header.