Thread: [xmlvm-users] Bug in NSData?

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Hi,
  I wrote a very simple Java->iPhone application to open a connection and
read the data in the response, but I found I only ever got back 26 bytes of
data. Here's the simplest code I could put together which exhibits the
problem...

private boolean finished = false;
     @Override
    public void applicationDidFinishLaunching(UIApplication app) {
        try {
        final NSURL url = NSURL.URLWithString("http://www.google.com");
        final NSMutableURLRequest req = new NSMutableURLRequest(url);

        NSURLConnectionDelegate delegate = new NSURLConnectionDelegate() {
        @Override
        public void connectionDidFailWithError(
        NSURLConnection connection, NSError error) {
        super.connectionDidFailWithError(connection, error);
        System.out.println("Error [" + error + "]");
        }

        @Override
        public void connectionDidFinishLoading(
        NSURLConnection connection) {
        super.connectionDidFinishLoading(connection);
        finished = true;
        System.out.println("Finish loading");
        }

        @Override
        public void connectionDidReceiveData(
        NSURLConnection connection, NSData data) {
        super.connectionDidReceiveData(connection, data);
        System.out.println("Received data [" + new String(data.getBytes()) +
"]");
        }
        };

        NSURLConnection.connectionWithRequest(req, delegate);

               // Wait until all the data has been received or we hit a 20s
limit.
        int i = 0;
        while (!finished && i < 20) {
        Thread.sleep(1000);
        i++;
        }
        }
        catch (Exception e) {
        System.err.println("Exception doing HTTP" + e);
        }
    }

I would have expected multiple "Received Data[.......]" messages but I only
ever get one of 26 characters. I took a look at the NSData java class,
specifically the readData method and I can see why it is failing. The
do/while loop in there only continues to read data if its buffer has been
filled and assumes that if the read() method returns a read count of less
than the buffer size that all the data has been read. Using the code above
the response contains an initial 26 bytes and consequently stops as the
buffer in NSData has not been completely filled. I wrote an equivalent pure
java application and it exhibits the same behaviour using the readData code.
Rewriting the readData method so it keeps reading until -1 is returned and
buffering the code appropriately retrieves all the data which is
approximately 9k bytes.

Is this a bug or have I done something wrong? Would the code work properly
if the application were running on an iPhone rather than in the Emulator?

Thanks,
Alex