rxtx com端口

Question

I am using rxtx api to read data from a GPS device over a com port. Right now I'm finding the correct com port by reading a config file and looking for the port listed. The problem that I'm having is that if the device is unplugged the com port could change then the user has to know to change the config file. I wrote an app similar to this in c# and was able to list the windows device name instead of the com port and I cycled through the com ports until the device name matched the name in the config file. Using that method nothing in the config file has to change even if the com port being used changes. Is there a way to do that with the rxtx api?

Thanks in advance!

Answer 1

If anyone is interested...

I created a windows service in C# that monitors a socket. If a client connects to that socket the service gathers port name, and device id that is on that port and sends the data in a string over the com port the client can then parse apart the string to get the data it needs.

In my case the string being passed is: "ACPI\\PNP0501 *PNP0501 ,COM1 ,PCI\\VEN_8086&DEV_29B7&SUBSYS_02111028&REV_02 PCI\\VEN_8086&DEV_29B7&SUBSYS_02111028 PCI\\VEN_8086&DEV_29B7&CC_070002 PCI\\VEN_8086&DEV_29B7&CC_0700 ,COM3 ,USB\\Vid_067b&Pid_2303&Rev_0400 USB\\Vid_067b&Pid_2303 ,COM5"

When I parse it I can see that ACPI\\PNP0501 *PNP0501 is the device id for COM 1, there are three device id's for COM3, and two device ids on COM5.

This may not be the best way to handle this but it is good enough for my needs and it saved me from JNI. :)

Answer 2

CommPortIdentifier.getPortIdentifiers lists all ports in the system that are usable by the Javacomm API. Iterate through them to find the port your device is connected to.

Answer 3

If you want to get the name associated with the device on the COM port (particularly if a driver is installed to provide it), you'll have to do so with a smidge of the dreaded Java->Native Interface to talk to the Windows APIs that gather this information. C# is nice, in that this information is gathered and provided to you, but in Java you have to go this extra step.

Windows Function Discovery may prove useful. I'm not certain exactly what API provides this functionality.