The JavaPOS standard defines the set of Java language retail device interfaces for use by Java retail applications. It also provides a reference implementation for the corresponding Device Control logic needed to connect these applications to the JavaPOS Device Services written by the actual device manufactorers.

The information below will be of primary use to developers trying to write a JavaPOS Device Service for a specific retail peripheral product "once" and have it be accessible and controllable by JavaPOS application programs anywhere.

In other words, those who need to extend the Java promise of OS and hardware neutrality down to the device driver level should keep reading.

Basically the missing Java piece here is the ability to directly access physical devices connected via the various IO bus configurations which might be present on a given POS terminal configuration, in a consistent and unchanging manner.

RS232 serial ports and IEEE 1284 parallel ports

If you want to configure pure Java Device Services which can communicate with devices that are connected via RS232 or IEEE 1284 ports then you will need to include the javax.comm package. Basically, by using the JavaComm package, a device driver / JavaPOS Device Service can be supplied for every platform on which JavaComm is supported.

JavaComm provides the following capabilities:

• Enumerate ports available on the system.
• Open and claim ownership of ports.
• Resolve port ownership contention between multiple applications.
• Perform asynchronous and synchronous I/O on ports.
• Receive Beans-style events describing communication port state changes.

Some of the primary JavaComm sites are listed below:

1. JavaComm V3.0 from Sun, for Linux and Solaris at:
   http://java.sun.com/products/javacomm (Select "Downloads")


2. JavaComm contained in IBM's JRE download for Windows (for IBM systems only) at: http://www-106.ibm.com/developerworks/java/jdk/


3. SerialIO provides RS232 JavaComm support on more than 26 platforms. Ongoing service contracts are available. See: http://www.serialio.com/products/serialport/serialport.htm


4. A rather outdated Linux Freeware mapping of JavaComm (RS232 only) See: http://www.rxtx.org (Then select "CommAPI" choice from top bar)