The most obvious issue is that the interface in Listing 6 requires a JNI call for each bit set or retrieved, as well as a JNI call to read a byte from, or write a byte to, the serial port.

Mode of serial port pair: synchronous clock device through the serial port read per second pair a serial output time information, serial port and RS232 interface and RS422 interface.

This can be useful when polling a serial port for data, as your program can determine the number of bytes in the input buffer before attempting a read.