how do you want to use bluetooth without bluetooth API?
...how do you want to paint w/o a grpahics API, how do you want to write w/o a pen? :-)
There must always be an API for any kind of functionality.
The L2CAP is not API, it's protocol and there must be an API implementing this protocol. For the Java ME world you have to use the Bluetooth API defined in JSR-82 - which must be implemented by the device you want to run the application on.
PS: I've heard about an option to connect via BT using standard IO connecotr using some special connection string, but I've never tried it and I have no info about it.