Download and save half way though

Question

If I have only downloaded a file half way through (ie I restarted the computer before it had finished) and then I want to restart it downloading half way in the file, so I don't have to totally restart it. This is what I have done so far to download a file:
try {
URL url = nextSpace.getUrl(sn); // Gets Url
fileName = nextSpace.getFileName(sn); // Gets Name
FileOutputStream fileoutputstream1 = new FileOutputStream(fileName);
int character;
URLConnection urlconnection = url.openConnection();
InputStream in = urlconnection.getInputStream();
while((character = in.read()) != -1) {
fileoutputstream1.write((char) character);
fileoutputstream1.close();
in.close();
} catch (Exception e) {}
I've slightly modified it so there is less code. I know how to start downloading from a certain place with this:
urlconnection.setRequestProperty("Range","bytes=fileName.length()-urlconnection.getContentLength()");
But how do I save what I've download to the correct place in the file??? And also if it is possible to save into the file 10 or so bytes in (over writing some data), so just in case the data at the end of the file was damaged when the connect was brocken.
So to sum it up, how do I write to a file so far in??
Thanks for your help again
Ben Black

Answer 1

check out java.io.RandomAccessFile
Be careful when using Range header, the server may send the whole content rather than the specified range of bytes. check the response code. 206 implies the server is sending partial content, as you requested.
Hope it helps.