javax.comm
Class SerialPort

java.lang.Object
  javax.comm.CommPort
      javax.comm.SerialPort

public abstract class SerialPort

extends CommPort

An RS-232 serial communications port. SerialPort describes the low-level interface to a serial communications port made available by the underlying system. SerialPort defines the minimum required functionality for serial communications ports.

Author:

Jagane Sundar

See Also:

CommPort, CommPortIdentifier

Field Summary

static int	DATABITS_5 5 data bit format.
static int	DATABITS_6 6 data bit format.
static int	DATABITS_7 7 data bit format.
static int	DATABITS_8 8 data bit format.
static int	FLOWCONTROL_NONE Flow control off.
static int	FLOWCONTROL_RTSCTS_IN RTS/CTS flow control on input.
static int	FLOWCONTROL_RTSCTS_OUT RTS/CTS flow control on output.
static int	FLOWCONTROL_XONXOFF_IN XON/XOFF flow control on input.
static int	FLOWCONTROL_XONXOFF_OUT XON/XOFF flow control on output.
static int	PARITY_EVEN EVEN parity scheme.
static int	PARITY_MARK MARK parity scheme.
static int	PARITY_NONE No parity bit.
static int	PARITY_ODD ODD parity scheme.
static int	PARITY_SPACE SPACE parity scheme.
static int	STOPBITS_1 Number of STOP bits - 1.
static int	STOPBITS_1_5 Number of STOP bits - 1-1/2.
static int	STOPBITS_2 Number of STOP bits - 2.

Fields inherited from class javax.comm.CommPort

name

Constructor Summary

SerialPort()

Method Summary

abstract void	addEventListener(SerialPortEventListener lsnr) Registers a SerialPortEventListener object to listen for SerialEvents.
abstract int	getBaudRate() Gets the currently configured baud rate.
abstract int	getDataBits() Gets the currently configured number of data bits.
abstract int	getFlowControlMode() Gets the currently configured flow control mode.
abstract int	getParity() Get the currently configured parity setting.
abstract int	getStopBits() Gets the currently defined stop bits.
abstract boolean	isCD() Gets the state of the CD (Carrier Detect) bit in the UART, if supported by the underlying implementation.
abstract boolean	isCTS() Gets the state of the CTS (Clear To Send) bit in the UART, if supported by the underlying implementation.
abstract boolean	isDSR() Gets the state of the DSR (Data Set Ready) bit in the UART, if supported by the underlying implementation.
abstract boolean	isDTR() Gets the state of the DTR (Data Terminal Ready) bit in the UART, if supported by the underlying implementation.
abstract boolean	isRI() Gets the state of the RI (Ring Indicator) bit in the UART, if supported by the underlying implementation.
abstract boolean	isRTS() Gets the state of the RTS (Request To Send) bit in the UART, if supported by the underlying implementation.
abstract void	notifyOnBreakInterrupt(boolean enable) Expresses interest in receiving notification when there is a break interrupt on the line.
abstract void	notifyOnCarrierDetect(boolean enable) Expresses interest in receiving notification when the CD (Carrier Detect) bit changes.
abstract void	notifyOnCTS(boolean enable) Expresses interest in receiving notification when the CTS (Clear To Send) bit changes.
abstract void	notifyOnDataAvailable(boolean enable) Expresses interest in receiving notification when input data is available.
abstract void	notifyOnDSR(boolean enable) Expresses interest in receiving notification when the DSR (Data Set Ready) bit changes.
abstract void	notifyOnFramingError(boolean enable) Expresses interest in receiving notification when there is a framing error.
abstract void	notifyOnOutputEmpty(boolean enable) Expresses interest in receiving notification when the output buffer is empty.
abstract void	notifyOnOverrunError(boolean enable) Expresses interest in receiving notification when there is an overrun error.
abstract void	notifyOnParityError(boolean enable) Expresses interest in receiving notification when there is a parity error.
abstract void	notifyOnRingIndicator(boolean enable) Expresses interest in receiving notification when the RI (Ring Indicator) bit changes.
abstract void	removeEventListener() Deregisters event listener registered using addEventListener.
abstract void	sendBreak(int millis) Sends a break of millis milliseconds duration.
abstract void	setDTR(boolean dtr) Sets or clears the DTR (Data Terminal Ready) bit in the UART, if supported by the underlying implementation.
abstract void	setFlowControlMode(int flowcontrol) Sets the flow control mode.
void	setRcvFifoTrigger(int trigger) Deprecated. This was advisory only.
abstract void	setRTS(boolean rts) Sets or clears the RTS (Request To Send) bit in the UART, if supported by the underlying implementation.
abstract void	setSerialPortParams(int baudrate, int dataBits, int stopBits, int parity) Sets serial port parameters.

Methods inherited from class javax.comm.CommPort

close, disableReceiveFraming, disableReceiveThreshold, disableReceiveTimeout, enableReceiveFraming, enableReceiveThreshold, enableReceiveTimeout, getInputBufferSize, getInputStream, getName, getOutputBufferSize, getOutputStream, getReceiveFramingByte, getReceiveThreshold, getReceiveTimeout, isReceiveFramingEnabled, isReceiveThresholdEnabled, isReceiveTimeoutEnabled, setInputBufferSize, setOutputBufferSize, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DATABITS_5

public static final int DATABITS_5

5 data bit format.

See Also:

Constant Field Values

DATABITS_6

public static final int DATABITS_6

6 data bit format.

See Also:

Constant Field Values

DATABITS_7

public static final int DATABITS_7

7 data bit format.

See Also:

Constant Field Values

DATABITS_8

public static final int DATABITS_8

8 data bit format.

See Also:

Constant Field Values

STOPBITS_1

public static final int STOPBITS_1

Number of STOP bits - 1.

See Also:

Constant Field Values

STOPBITS_2

public static final int STOPBITS_2

Number of STOP bits - 2.

See Also:

Constant Field Values

STOPBITS_1_5

public static final int STOPBITS_1_5

Number of STOP bits - 1-1/2. Some UARTs permit 1-1/2 STOP bits only with 5 data bit format, but permit 1 or 2 STOP bits with any format.

See Also:

Constant Field Values

PARITY_NONE

public static final int PARITY_NONE

No parity bit.

See Also:

Constant Field Values

PARITY_ODD

public static final int PARITY_ODD

ODD parity scheme. The parity bit is added so there are an odd number of TRUE bits.

See Also:

Constant Field Values

PARITY_EVEN

public static final int PARITY_EVEN

EVEN parity scheme. The parity bit is added so there are an even number of TRUE bits.

See Also:

Constant Field Values

PARITY_MARK

public static final int PARITY_MARK

MARK parity scheme.

See Also:

Constant Field Values

PARITY_SPACE

public static final int PARITY_SPACE

SPACE parity scheme.

See Also:

Constant Field Values

FLOWCONTROL_NONE

public static final int FLOWCONTROL_NONE

Flow control off.

See Also:

Constant Field Values

FLOWCONTROL_RTSCTS_IN

public static final int FLOWCONTROL_RTSCTS_IN

RTS/CTS flow control on input.

See Also:

Constant Field Values

FLOWCONTROL_RTSCTS_OUT

public static final int FLOWCONTROL_RTSCTS_OUT

RTS/CTS flow control on output.

See Also:

Constant Field Values

FLOWCONTROL_XONXOFF_IN

public static final int FLOWCONTROL_XONXOFF_IN

XON/XOFF flow control on input.

See Also:

Constant Field Values

FLOWCONTROL_XONXOFF_OUT

public static final int FLOWCONTROL_XONXOFF_OUT

XON/XOFF flow control on output.

See Also:

Constant Field Values

Constructor Detail

SerialPort

public SerialPort()

Method Detail

getBaudRate

public abstract int getBaudRate()

Gets the currently configured baud rate.

Returns:

integer value indicating the baud rate

getDataBits

public abstract int getDataBits()

Gets the currently configured number of data bits.

Returns:

integer that can be equal to DATABITS_5, DATABITS_6, DATABITS_7, or DATABITS_8

getStopBits

public abstract int getStopBits()

Gets the currently defined stop bits.

Returns:

integer that can be equal to STOPBITS_1, STOPBITS_2, or STOPBITS_1_5

getParity

public abstract int getParity()

Get the currently configured parity setting.

Returns:

integer that can be equal to PARITY_NONE, PARITY_ODD, PARITY_EVEN, PARITY_MARK or PARITY_SPACE.

sendBreak

public abstract void sendBreak(int millis)

Sends a break of millis milliseconds duration. Note that it may not be possible to time the duration of the break under certain Operating Systems. Hence this parameter is advisory.

Parameters:

millis - duration of break to send

setFlowControlMode

public abstract void setFlowControlMode(int flowcontrol)
                                 throws UnsupportedCommOperationException

Sets the flow control mode.

Parameters:

flowcontrol - Can be a bitmask combination of

• FLOWCONTROL_NONE: no flow control
• FLOWCONTROL_RTSCTS_IN: RTS/CTS (hardware) flow control for input
• FLOWCONTROL_RTSCTS_OUT: RTS/CTS (hardware) flow control for output
• FLOWCONTROL_XONXOFF_IN: XON/XOFF (software) flow control for input
• FLOWCONTROL_XONXOFF_OUT: XON/XOFF (software) flow control for output
  Throws:
  UnsupportedCommOperationException - if any of the flow control mode was not supported by the underline OS, or if input and output flow control are set to different values, i.e. one hardware and one software. The flow control mode will revert to the value before the call was made.

getFlowControlMode

public abstract int getFlowControlMode()

Gets the currently configured flow control mode.

Returns:

an integer bitmask of the modes FLOWCONTROL_NONE, FLOWCONTROL_RTSCTS_IN, FLOWCONTROL_RTSCTS_OUT, FLOWCONTROL_XONXOFF_IN, and FLOWCONTROL_XONXOFF_OUT.

setRcvFifoTrigger

public void setRcvFifoTrigger(int trigger)

Deprecated. This was advisory only.

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.

Parameters:

trigger - level

setSerialPortParams

public abstract void setSerialPortParams(int baudrate,
                                         int dataBits,
                                         int stopBits,
                                         int parity)
                                  throws UnsupportedCommOperationException

Sets serial port parameters.

Parameters:

baudrate - If the baudrate passed in by the application is unsupported by the driver, the driver will throw an UnsupportedCommOperationException

dataBits -

• DATABITS_5: 5 bits
• DATABITS_6: 6 bits
• DATABITS_7: 7 bits
• DATABITS_8: 8 bits

stopBits -

• STOPBITS_1: 1 stop bit
• STOPBITS_2: 2 stop bits
• STOPBITS_1_5: 1.5 stop bits

parity -

• PARITY_NONE: no parity
• PARITY_ODD: odd parity
• PARITY_EVEN: even parity
• PARITY_MARK: mark parity
• PARITY_SPACE: space parity

Throws:

UnsupportedCommOperationException - if any of the above parameters are specified incorrectly. All four of the parameters will revert to the values before the call was made.

DEFAULT: 9600 baud, 8 data bits, 1 stop bit, no parity

setDTR

public abstract void setDTR(boolean dtr)

Sets or clears the DTR (Data Terminal Ready) bit in the UART, if supported by the underlying implementation.

Parameters:

dtr -

• true: set DTR
• false: clear DTR

isDTR

public abstract boolean isDTR()

Gets the state of the DTR (Data Terminal Ready) bit in the UART, if supported by the underlying implementation.

setRTS

public abstract void setRTS(boolean rts)

Sets or clears the RTS (Request To Send) bit in the UART, if supported by the underlying implementation.

Parameters:

rts -

• true: set RTS
• false: clear RTS

isRTS

public abstract boolean isRTS()

Gets the state of the RTS (Request To Send) bit in the UART, if supported by the underlying implementation.

isCTS

public abstract boolean isCTS()

Gets the state of the CTS (Clear To Send) bit in the UART, if supported by the underlying implementation.

isDSR

public abstract boolean isDSR()

Gets the state of the DSR (Data Set Ready) bit in the UART, if supported by the underlying implementation.

isRI

public abstract boolean isRI()

Gets the state of the RI (Ring Indicator) bit in the UART, if supported by the underlying implementation.

isCD

public abstract boolean isCD()

Gets the state of the CD (Carrier Detect) bit in the UART, if supported by the underlying implementation.

addEventListener

public abstract void addEventListener(SerialPortEventListener lsnr)
                               throws java.util.TooManyListenersException

Registers a SerialPortEventListener object to listen for SerialEvents. Interest in specific events may be expressed using the notifyOnXXX calls. The serialEvent method of SerialPortEventListener will be called with a SerialEvent object describing the event.

The current implementation only allows one listener per SerialPort. Once a listener is registered, subsequent call attempts to addEventListener will throw a TooManyListenersException without effecting the listener already registered.

All the events received by this listener are generated by one dedicated thread that belongs to the SerialPort object. After the port is closed, no more event will be generated. Another call to open() of the port's CommPortIdentifier object will return a new CommPort object, and the lsnr has to be added again to the new CommPort object to receive event from this port.

Parameters:

lsnr - The SerialPortEventListener object whose serialEvent method will be called with a SerialEvent describing the event.

Throws:

java.util.TooManyListenersException - If an initial attempt to attach a listener succeeds, subsequent attempts will throw TooManyListenersException without effecting the first listener.

removeEventListener

public abstract void removeEventListener()

Deregisters event listener registered using addEventListener.

This is done automatically at port close.

notifyOnDataAvailable

public abstract void notifyOnDataAvailable(boolean enable)

Expresses interest in receiving notification when input data is available. This may be used to drive asynchronous input. When data is available in the input buffer, this event is propagated to the listener registered using addEventListener.

The event will be generated once when new data arrive at the serial port. Even if the user doesn't read the data, it won't be generated again until next time new data arrive.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnOutputEmpty

public abstract void notifyOnOutputEmpty(boolean enable)

Expresses interest in receiving notification when the output buffer is empty. This may be used to drive asynchronous output. When the output buffer becomes empty, this event is propagated to the listener registered using addEventListener. The event will be generated after a write is completed, when the system buffer becomes empty again.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnCTS

public abstract void notifyOnCTS(boolean enable)

Expresses interest in receiving notification when the CTS (Clear To Send) bit changes.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• >

>

notifyOnDSR

public abstract void notifyOnDSR(boolean enable)

Expresses interest in receiving notification when the DSR (Data Set Ready) bit changes.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnRingIndicator

public abstract void notifyOnRingIndicator(boolean enable)

Expresses interest in receiving notification when the RI (Ring Indicator) bit changes.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnCarrierDetect

public abstract void notifyOnCarrierDetect(boolean enable)

Expresses interest in receiving notification when the CD (Carrier Detect) bit changes.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnOverrunError

public abstract void notifyOnOverrunError(boolean enable)

Expresses interest in receiving notification when there is an overrun error.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnParityError

public abstract void notifyOnParityError(boolean enable)

Expresses interest in receiving notification when there is a parity error.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnFramingError

public abstract void notifyOnFramingError(boolean enable)

Expresses interest in receiving notification when there is a framing error.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification

notifyOnBreakInterrupt

public abstract void notifyOnBreakInterrupt(boolean enable)

Expresses interest in receiving notification when there is a break interrupt on the line.

This notification is hardware dependent and may not be supported by all implementations.

Parameters:

enable -

• true: enable notification
• false: disable notification