Java com port problem

I am trying to read some data of GPS from COM1 port. I have to show a message that the device is not connected if the gps device is not attached with the com port. I a开发者_如何转开发m using rxtxComm.jar, rxtxSerial.dll, gpsinput.jar in my project.

I am also facing problem from reading GPS data from com port.In my input stream no data is coming but the gps device is throughing data at the com port (I checked it by using hyper terminal).

code

Please refer to this.

How to send data to COM PORT using JAVA?