Package de.gmxhome.conrad.JNALinux

Class JnaLinuxSerial

java.lang.Object

de.gmxhome.conrad.JNALinux.JnaLinuxSerial

All Implemented Interfaces:

SerialIOAdapter, AutoCloseable

public class JnaLinuxSerial
extends Object
implements SerialIOAdapter

Implementation of SerialIOAdapter using native Linux calls via JNA. Can be used for all similar operating systems as long as the arguments of open, read, write, close, poll and system match the interface.
Setting baud rate, number of stop bits, data size and parity will be performed using an external command. This command will be built using property values read from de.gmxhome.conrad.JNALinux.JnaLinuxSerial.properties and is of the form

prefix baud size stop parity < port

, where

• prefix will be replaced by the property value STTYPREFIX (default: "stty raw -echo"),
• baud will be replaced by one of the property values BD1200 (default: "1200"), BD2400 (default: "2400"), BD4800 (default: "4800"), BD9600 (default: "9600"), BD19200 (default: "19200"), BD38400 (default: "38400"), BD57600 (default: "57600"), BD115200 (default: "115200"), BD128000 (default: "") or BD256000 (default: ""),
• size will be replaced by one of the property values CS7 (default: "cs7") or CS8 (default: "cs8"),
• stop will be replaced by one of the property values SB1 (default: "-cstopb") or SB2 (default: "cstopb"),
• parity will be replaced by one of the property values PARNO (default: "-parenb"), PARODD (default: "parenb parodd"), PAREVEN (default: "parenb -parodd"), PARMARK (default: ""), PARSPACE (default: "") and
• port will be replaced by the the port as passed to method open.

The default values work well for most Linux distributions. For Linux distributions or other Unix-like operating systems which use a different syntax for the command that may be used to set the communication parameters of a COM port, the corresponding property values must be changed. If one of the values is not supported, it must remain empty.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	JnaLinuxSerial.LibCExt	Interface for some I/O relevant functions provided by Linux and other Unix-like operating systems.

Nested classes/interfaces inherited from interface de.gmxhome.conrad.jpos.jpos_base.SerialIOAdapter

SerialIOAdapter.NotFoundException

Field Summary

Fields inherited from interface de.gmxhome.conrad.jpos.jpos_base.SerialIOAdapter

B_115200, B_1200, B_128000, B_19200, B_2400, B_256000, B_38400, B_4800, B_57600, B_9600, Baudrate, D_7, D_8, P_EVEN, P_MARK, P_NO, P_ODD, P_SPACE, S_1, S_2, T_BAUD, T_DATA, T_PARITY, T_STOP

Constructor Summary

Constructors

Constructor	Description
JnaLinuxSerial()	Constructor.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns the number of received bytes that can be read without blocking.
void	close()	Close the communication port.
boolean	exits(String port)	Checks whether a port still exists.
void	flush()	Flushed input and output buffers.
int[][]	getCommunicationConstants(int constantType)	Retrieves an array of integer pairs specifying all valid parameters for the given constant type.
void	open(String port)	Opens a port for serial IO.
byte[]	read(int count, int timeout)	Reads data from a communication port.
void	setParameters(int baudrate, int databits, int stopbits, int parity)	Set communication parameters for speed, data size and frame structure. baudrate specifies the baud rate, databits the number of data bits, stopbits the number of stop bits per data unit and parity the kind of parity bit, if parity shall be used.
void	write(byte[] buffer)	Write the given byte buffer to the com port.

Methods inherited from class java.lang.Object

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

Constructor Details

JnaLinuxSerial

public JnaLinuxSerial()

Constructor. Creates communication adapter.

Method Details

open

public void open(String port)
          throws IOException

Description copied from interface: SerialIOAdapter

Opens a port for serial IO.

Specified by:

open in interface SerialIOAdapter

Parameters:

port - Port. e.g. COM2

Throws:

IOException - If the port does not exist or in case of IO errors.

close

public void close()
           throws IOException

Description copied from interface: SerialIOAdapter

Close the communication port.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface SerialIOAdapter

Throws:

IOException - In case of IO error.

setParameters

public void setParameters(int baudrate,
 int databits,
 int stopbits,
 int parity)
                   throws IOException

Description copied from interface: SerialIOAdapter

Set communication parameters for speed, data size and frame structure.
baudrate specifies the baud rate, databits the number of data bits, stopbits the number of stop bits per data unit and parity the kind of parity bit, if parity shall be used. Keep in mind that these constants can vary between adapter implementations. The application should use method getCommunicationConstants to retrieve the valid constant values and the corresponding adapter independent values.

Specified by:

setParameters in interface SerialIOAdapter

Parameters:

baudrate - Baud rate.

databits - Bits per date unit.

stopbits - Number of stop bits to be used.

parity - Parity constant.

Throws:

IOException - If an IO error occurs of if a parameter is invalid.

available

public int available()
              throws IOException

Description copied from interface: SerialIOAdapter

Returns the number of received bytes that can be read without blocking.

Specified by:

available in interface SerialIOAdapter

Returns:

Number of bytes just in device input buffer.

Throws:

IOException - In case of an IO error

read

public byte[] read(int count,
 int timeout)
            throws IOException

Description copied from interface: SerialIOAdapter

Reads data from a communication port. If no data are available, read blocks until data are available or the specified timeout has been reached.

Specified by:

read in interface SerialIOAdapter

Parameters:

count - Maximum number of bytes to be read.

timeout - Maximum time to wait for data in milliseconds.

Returns:

byte array holding all available data bytes

Throws:

IOException - In case of an IO error.

write

public void write(byte[] buffer)
           throws IOException

Description copied from interface: SerialIOAdapter

Write the given byte buffer to the com port.

Specified by:

write in interface SerialIOAdapter

Parameters:

buffer - Buffer to be written

Throws:

IOException - If the port has not been opened or in case of an IO error.

flush

public void flush()
           throws IOException

Description copied from interface: SerialIOAdapter

Flushed input and output buffers.

Specified by:

flush in interface SerialIOAdapter

Throws:

IOException - In case of an IO error.

exits

public boolean exits(String port)

Description copied from interface: SerialIOAdapter

Checks whether a port still exists. In case of serial communication via Bluetooth or USB, ports can go lost.

Specified by:

exits in interface SerialIOAdapter

Parameters:

port - Port to be checked.

Returns:

true if the port still exists, false otherwise-

getCommunicationConstants

public int[][] getCommunicationConstants(int constantType)

Description copied from interface: SerialIOAdapter

Retrieves an array of integer pairs specifying all valid parameters for the given constant type. constantType can be one of T_BAUD, T_DATA, T_STOP or T_PARITY. The method returns an array of integer pairs where the first element specifies the constant value to be passed to the setParameters method of the SerialIOProcessor and the second element specifies the corresponding value to be passed to the setParameters method of the specific SerialIOAdapter implementation.

Specified by:

getCommunicationConstants in interface SerialIOAdapter

Parameters:

constantType - Type of constants to be requested.

Returns:

Array of integer pairs containing the adapter independent and adapter specific constants of the requested type. null if constantType is invalid.