Read a file continously via HTTP with Java

Question

What I need to do is basically reading a file which is continously growing, but in every interval I just want to read the new that was appended to the file.

I found a lot of ways to do this with a file on my filesystem, but all these require that I download the file before I can do the magic using the RandomAccessFile-Object.

Is there a way to do this with an online-file like http://myurl.com/123.txt? So that I just stream the data added in the last 2 minutes?

Thanks a lot! noise

no. i have no influence on the server or the file. I just know the link. — tommueller
– tommueller, Commented Oct 20, 2013 at 10:59

Community · Accepted Answer · 2017-05-23 12:10:59Z

1

If the server supports it, you can use the Range header to request bytes from a given offset. Do this repeatedly to poll the file for new bytes.

Pseudocode:

long offset = 0;
while (true) {
    request.setHeader("Range: bytes=" + offset + "-");
    request.send();
    request.readResponse();
    offset += theNumberOfBytesRead;
    Thread.sleep(someRespectfulAmountOfTime);
}

See this question for details about how the server is likely to respond if it does or doesn't have more bytes available.

To get "data added in the last 2 minutes", you have to keep track of what offset was two minutes ago.

edited May 23, 2017 at 12:10

CommunityBot

11 silver badge

answered Oct 20, 2013 at 11:10

mpartel

4,5021 gold badge27 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Read a file continously via HTTP with Java

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related