de.htw.berlin.polysun4diac.forte.comm

Interface ICommunicationLayer

All Known Implementing Classes:

AbstractCommunicationLayer, de.htw.berlin.polysun4diac.forte.comm.AbstractDataBufferLayer, CommFunctionBlockLayer, ForteDataBufferLayer, IPcommunicationLayer, TCPclientCommLayer, TCPcommunicationLayer, TCPserverCommLayer, UDPcommunicationLayer, UDPpublisherCommLayer, UDPsubscriberCommLayer

public interface ICommunicationLayer

Provides the public interface for an OSI layer. Loosely based on the OSI layer interface implemented in FORTE.

Author:

Marc Jakobi

HTW Berlin

July 2017

See Also:

FORTE communication architecture

Method Summary

Modifier and Type	Method and Description
boolean	closeConnection() Closes this layer and calls closeConnection() on the layer below.
ICommunicationLayer	getAbove()
ICommunicationLayer	getBelow()
boolean	getConnectionState()
byte[]	getRawBytes()
boolean	openConnection(CommLayerParams params) Opens the connection and sets up the communication stack.
byte	readByte() Reads a byte from the communication layer below or the connected device if this layer is the bottom layer.
double	readDouble() Reads 8 bytes from the communication layer below or the connected device if this layer is the bottom layer.
float	readFloat() Reads 4 bytes from the communication layer below or the connected device if this layer is the bottom layer.
long	readLong() Reads 4 bytes from the communication layer below or the connected device if this layer is the bottom layer.
void	recvData() Performs the necessary actions for receiving data.
void	sendData(byte[] data) Performs the necessary actions for sending data.
void	sendData(byte[] data, int off, int len) Performs the necessary actions for sending data.
void	setAbove(ICommunicationLayer layer) Sets the communication layer above this layer.
void	setBelow(ICommunicationLayer layer) Sets the communication layer below this layer.

Method Detail

openConnection

boolean openConnection(CommLayerParams params)
                throws java.io.IOException

Opens the connection and sets up the communication stack. If necessary, additional layers below this layer are created.

Parameters:

params - CommLayerParams object holding the connection info

Returns:

true if the connection was opened successfully, false otherwise

Throws:

java.io.IOException

closeConnection

boolean closeConnection()
                 throws java.io.IOException

Closes this layer and calls closeConnection() on the layer below.

Returns:

true if the connection was closed successfully, false otherwise

Throws:

java.io.IOException

sendData

void sendData(byte[] data,
              int off,
              int len)
       throws java.io.IOException

Performs the necessary actions for sending data.

Parameters:

data - Byte array containing the data

Offset - (start of write operation)

len - Length of the data to be sent

Throws:

java.io.IOException

sendData

void sendData(byte[] data)
       throws java.io.IOException

Performs the necessary actions for sending data. Equivalent to calling sendData(data, 0, data.length);

Parameters:

data - Byte array containing the data

Throws:

java.io.IOException

recvData

void recvData()
       throws java.io.IOException

Performs the necessary actions for receiving data.

Throws:

java.io.IOException

getAbove

ICommunicationLayer getAbove()

Returns:

the communication layer above this layer

getBelow

ICommunicationLayer getBelow()

Returns:

the communication layer below this layer

setAbove

void setAbove(ICommunicationLayer layer)

Sets the communication layer above this layer.

setBelow

void setBelow(ICommunicationLayer layer)

Sets the communication layer below this layer.

readByte

byte readByte()
       throws java.io.IOException

Reads a byte from the communication layer below or the connected device if this layer is the bottom layer.

Throws:

java.io.IOException

readLong

long readLong()
       throws java.io.IOException

Reads 4 bytes from the communication layer below or the connected device if this layer is the bottom layer.

Returns:

the long value represented by the 4 bytes.

Throws:

java.io.IOException

readDouble

double readDouble()
           throws java.io.IOException

Reads 8 bytes from the communication layer below or the connected device if this layer is the bottom layer.

Returns:

the double value represented by the 8 bytes.

Throws:

java.io.IOException

readFloat

float readFloat()
         throws java.io.IOException

Reads 4 bytes from the communication layer below or the connected device if this layer is the bottom layer.

Returns:

the float value represented by the 4 bytes.

Throws:

java.io.IOException

getConnectionState

boolean getConnectionState()

Returns:

true if the layer is connected, false otherwise.

getRawBytes

byte[] getRawBytes()

Returns:

a byte array holding the raw data retrieved by calling recvData()