[DIRMINA-646] More than required data sent on serial port through serial transport

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-M3
• Fix Version/s: 2.0.0-M5
• Component/s: Transport
• Environment: MINA : 2.0.0-M3; Netbeans 6.5; Serial port (both hardware COM1 and using com0com's virtual serial ports); JDK 1.6.10; Windows XP (Service Pack 3)
• Assignee: Julien Vermillard
• Reporter: Akbar Munir Chaudhary
• Created: 11/Dec/08 06:52
• Updated: 07/Jun/09 07:56
• Resolved: 09/Mar/09 09:20

Description

The serial transport sends more then required data when IoSession.write() is called with the IoBuffer. The following code is the basic usage of serial transport:

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SerialAddress a = new SerialAddress("COM1", 115200, SerialAddress.DataBits.DATABITS_8, SerialAddress.StopBits.BITS_1, SerialAddress.Parity.NONE, SerialAddress.FlowControl.NONE);
IoConnector c = new SerialConnector();
c.setHandler(this);
ConnectFuture cf = c.connect(a);
cf.awaitUninterruptibly();

System.out.println("Connection = " + cf.isConnected());

if (cf.isConnected())

{ IoSession s = cf.getSession(); IoBuffer b = IoBuffer.allocate(32); b.put(new String("this is a test message").getBytes()); b.flip(); WriteFuture wf = s.write(b); wf.awaitUninterruptibly(5, TimeUnit.SECONDS); System.out.println("Message Written = " + wf.isWritten()); }

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The message <code>this is a test message</code> should have been sent on the serial port COM1. But the actual output received is (output captured through HDD Free Serial Port Monitor) :

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74 68 69 73 20 69 73 20 61 20 74 65 73 74 20 6D this is a test m
65 73 73 61 67 65 00 00 00 00 00 00 00 00 00 00 essage..........
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I have looked into the code, and the reason appears to be the following statement on line # 184 in the file SerialSessionImpl.java.

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outputStream.write(buf.array());
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Since buf.array() returns the complete array in the IoBuffer, regardless of the actual count of valid data, so all bytes are sent. I changed this statement to:

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outputStream.write(buf.array(), buf.position(), writtenBytes);
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to ensure that only the required bytes starting from the first unread position is sent on the serial port. This works so far for all my cases.

Thanks,
Akbar.