Error using transferTo function on VMS for long files

Question

Here is the code snippet that fails, as you can tell I am not giving all the code since it is not required to understand the problem.
This occurs on OpenVMS
Welcome to OpenVMS (TM) Alpha Operating System, Version V7.3-2
java version "1.4.2"
Java(TM) 2 Runtime Environment, Standard Edition
Classic VM (build 1.4.2-5, 03/06/2006-23:29, native threads, nojit)
The error only occurs on files with very long line lengths (20 000+ characters in the line) and file size is not an issue.
Thanks in advance for your help in resolving this issue.
private FileChannel fileChannelInbound;
private SocketChannel socketChannelOutbound;
private Socket client;
client = new Socket(hostname,portNumber);
socketChannelOutbound = SocketChannel.open(client.getRemoteSocketAddress());
File fIn = new File(file);
fileChannelInbound = new FileInputStream(fIn).getChannel();
fileChannelInbound.transferTo(0,fileChannelInbound.size(),socketChannelOutbound);
fileChannelInbound.close();This is the trace of the error.
java.io.IOException: invalid buffer length
at sun.nio.ch.FileDispatcher.write0(Native Method)
at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java)
at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java)
at sun.nio.ch.IOUtil.write(IOUtil.java)
at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java)
at sun.nio.ch.FileChannelImpl.transferToTrustedChannel(FileChannelImpl.java)
at sun.nio.ch.FileChannelImpl.transferTo(FileChannelImpl.java)
at WebReturnResult.sendFile(WebReturnResult.java)
at WebReturnResult.sendResults(WebReturnResult.java)
at WebReturnResult.<init>(WebReturnResult.java)
at WebReturnResult.main(WebReturnResult.java)

Answer 1

Hi ,
Unfortunately this is an issue in the underlying driver for the USB device. It should be fixed in the next DAQ release.
One way you could work around this problem is by having a delay after the read and the next line of code.
i.e
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
DAQmxErrChk DAQmxReadAnalogScalarF64(taskHandle, 10#, data, ByVal 0&
Sleep(250)
acquisitionDataTextBox.Text = CStr(data)
Hope this helps...
Nandan Dharwadker
Staff Software Engineer
Measurement Studio Hardware Team