Unten stehendes direkt kopiert aus der Dokumentation zur javacomm. Die Software dazu musst Du Dir schon selbst schreiben (werde aber mal ein paar benchmarks zur java2D Geschwindigkeit machen) Ernst nehmen musst Du mich deswegen natürlich nicht. Schneller gings auch nicht, war essen.

o isCD()
Gets the state of the CD (Carrier Detect) bit in the UART.
o isCTS()
Gets the state of the CTS (Clear To Send) bit in the UART.
o isDSR()
Gets the state of the DSR (Data Set Ready) bit in the UART.
o isDTR()
Gets the state of the DTR (Data Terminal Ready) bit in the UART.
o isRI()
Gets the state of the RI (Ring Indicator) bit in the UART.
o isRTS()
notifyOnCTS(boolean)
Expresses interest in receiving notification when the CTS (Clear To Send) bit changes.
o notifyOnDataAvailable(boolean)
Expresses interest in receiving notification when input data is available.
o notifyOnDSR(boolean)
Expresses interest in receiving notification when the DSR (Data Set Ready) bit changes.
o notifyOnFramingError(boolean)
Expresses interest in receiving notification when there is a framing error.
o notifyOnOutputEmpty(boolean)
Expresses interest in receiving notification when the output buffer is empty.
o notifyOnOverrunError(boolean)
Expresses interest in receiving notification when there is an overrun error.
o notifyOnParityError(boolean)
Expresses interest in receiving notification when there is a parity error.
o notifyOnRingIndicator(boolean)
Expresses interest in receiving notification when the RI (Ring Indicator) bit changes.
sendBreak(int)
Sends a break of millis milliseconds duration.
o setDTR(boolean)
Sets or clears the DTR (Data Terminal Ready) bit in the UART.
o setFlowControlMode(int)
Sets the flow control mode.
o setRcvFifoTrigger(int)
Set the Receive Fifo trigger level If the UART has a FIFO and if it can have programmable trigger levels, then this method will cause the UART to raise an interrupt after trigger bytes have been received. Deprecated.
o setRTS(boolean)
Sets or clears the RTS (Request To Send) bit in the UART.
o setSerialPortParams(int, int, int, int)
Sets serial port parameters.