I want to write some programs using Java comm api. I am not able to find site/page from which I can download this API. Can anyone please tell me where can I get this API?
Download javax.comm api library from here : http://www.java2s.com/Code/Jar/c/Downloadcomm20jar.htm
In my opinion, the best alternative to javax.comm is rxtx.
For sending sms over serial connection you have to use AT command.
Here are some examples on other languages (but the concept is same).
http://linux-101.org/script/python-code-sending-sms-messages-usb-connected-mobile-phone http://www.developershome.com/sms/howToSendSMSFromPC.asp http://www.codeproject.com/KB/vb/AT_commands.aspx
I'd suggest you to test the commands on app like hyperterminal( alternative for win 7 : http://helpdeskgeek.com/windows-7/windows-7-hyperterminal/) first.