Java Serial Communication PortInUseException

Question

I have an SMS-based Java application using CommV3 drivers for Serial communication to a GSM Modem. I have two separate codes, one for sending messages and one for receiving messages. Each code works perfectly when executed individually.

Now, when I want to integrate both these codes, I get a PortInUseException, which might be obvious. But, I am not sure where to start from.

Could I get pointers/ links/ tutorials where I could start resolving my issue. I do not have a clue where I should start from.

Thanks in advance!

Costis Aivalis · Accepted Answer · 2013-01-28T23:02:03.110

1

Make sure that your code uses one SerialPort and not two. Then there is no problem reading or writing to this port.

SerialPort serialPort;
InputStream inStream;
OutputStream outStream;

serialPort = (SerialPort) portId.open(...);
serialPort.setFlowControlMode(...);
serialPort.setSerialPortParams(...);

inStream = serialPort.getInputStream ();
outStream = serialPort.getOutputStream ();

PS: SMSLib is an excellent Java library (ported to .NET Framework as well) which allows you to send/receive SMS messages via a compatible GSM modem or GSM phone. SMSLib also supports some bulk SMS operators. It is free and very stable.

edited Jan 28 '13 at 23:02

answered Jan 28 '13 at 08:19

Costis Aivalis

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I dont understand the parameters of the `portId.open(...)`. The API says appname and timeout... I guess I will look on these lines. – GreenDroid Jan 28 '13 at 21:20
There are two parameters: The application's name and the timeout in milliseconds. Example: `portId.open("MySMSApp", 5000);` – Costis Aivalis Jan 28 '13 at 21:51
I have already used the Javax Comm library and so am hesitant on moving to SMSLib. However, if all else fails, I will take up your suggestion. Thanks! – GreenDroid Jan 28 '13 at 23:09
I am sure that nothing will fail. Still SMSLib offers a lot of convenience. – Costis Aivalis Jan 28 '13 at 23:21
Thanks for the encouragement! I will definitely look at SMSLib too. – GreenDroid Jan 30 '13 at 03:00
I finally figured it out. I understand I never closed the port for the other code to start using it... `serialPort.close()` – GreenDroid Jan 30 '13 at 21:12
If you unite your code, you will only need to close() once, at the end of the program. – Costis Aivalis Jan 30 '13 at 21:35

score 0 · Answer 2 · answered Jan 28 '13 at 08:16

0

Probably you can separate out the listener code (which binds to a port) from 2 codes . and dedicate to the appropriate code segment based on send / recieve.

answered Jan 28 '13 at 08:16

TheWhiteRabbit

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That is exactly what I am not able to figure out... This is my first time programming with serial communication... – GreenDroid Jan 28 '13 at 21:15

Java Serial Communication PortInUseException

2 Answers2