de.avetana.bluetooth.l2cap
Class L2CAPConnectionImpl

java.lang.Object
  de.avetana.bluetooth.connection.BTConnection
      de.avetana.bluetooth.l2cap.L2CAPConnectionImpl

All Implemented Interfaces:

Connection, L2CAPConnection

public class L2CAPConnectionImpl

extends BTConnection

implements L2CAPConnection

The implementation of the javax.bluetooth.L2CAPConnection class.

COPYRIGHT:
(c) Copyright 2004 Avetana GmbH ALL RIGHTS RESERVED.

This file is part of the Avetana bluetooth API for Linux.

The Avetana bluetooth API for Linux is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

The Avetana bluetooth API is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

The development of the Avetana bluetooth API is based on the work of Christian Lorenz (see the Javabluetooth Stack at http://www.javabluetooth.org) for some classes, on the work of the jbluez team (see http://jbluez.sourceforge.net/) and on the work of the bluez team (see the BlueZ linux Stack at http://www.bluez.org) for the C code. Classes, part of classes, C functions or part of C functions programmed by these teams and/or persons are explicitly mentioned.



Description:
This class is an implementation of the javax.bluetooth.L2CAPConnection class and opens a new L2CAP connection with a remote BT device

See Also:

L2CAPConnection

Field Summary

protected int	m_receiveMTU
protected int	m_transmitMTU

Fields inherited from class de.avetana.bluetooth.connection.BTConnection

closed, dataBuffer, fid, m_remote

Fields inherited from interface javax.bluetooth.L2CAPConnection

DEFAULT_MTU, MINIMUM_MTU

Constructor Summary

	L2CAPConnectionImpl(int fid) Creates a new instance of L2CAPConnectionImpl and set the connection ID
	L2CAPConnectionImpl(int fid, java.lang.String addr) Creates a new instance of L2CAPConnectionImpl.
protected	L2CAPConnectionImpl(int fid, java.lang.String addr, int transmit, int receive) Creates a new instance of L2CAPConnectionImpl.

Method Summary

static L2CAPConnection	createL2CAPConnection(JSR82URL url) Creates a new L2CAP connection with a remote BT device.
int	getReceiveMTU() Returns the ReceiveMTU that the connection supports.
int	getTransmitMTU() Returns the MTU that the remote device supports.
boolean	ready() Determines if there is a packet that can be read via a call to receive().
int	receive(byte[] inBuf) Reads a packet of data.
void	send(byte[] data) Requests that data be sent to the remote device.
void	setConnectionURL(JSR82URL a_url) Sets the connection URL.

Methods inherited from class de.avetana.bluetooth.connection.BTConnection

available, close, getConnectionID, getRemoteDevice, isClosed, newData, read, setRemoteDevice

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.microedition.io.Connection

close

Field Detail

m_transmitMTU

protected int m_transmitMTU

m_receiveMTU

protected int m_receiveMTU

Constructor Detail

L2CAPConnectionImpl

public L2CAPConnectionImpl(int fid)

Creates a new instance of L2CAPConnectionImpl and set the connection ID

Parameters:

fid - the connection ID

L2CAPConnectionImpl

public L2CAPConnectionImpl(int fid,
                           java.lang.String addr)

Creates a new instance of L2CAPConnectionImpl. Set the connection ID and the remote device

Parameters:

fid - The connection ID

addr - The address of the remote device

L2CAPConnectionImpl

protected L2CAPConnectionImpl(int fid,
                              java.lang.String addr,
                              int transmit,
                              int receive)

Creates a new instance of L2CAPConnectionImpl. Initializes the data buffer, the different MTU values and the connection properties (Remote device, connection ID)

Parameters:

fid - The connection ID

addr - The address of the remote device

transmit - The desired value of transmitMTU

receive - The desire value of receiveMTU

Method Detail

setConnectionURL

public void setConnectionURL(JSR82URL a_url)

Sets the connection URL.

Parameters:

a_url - The new connection URL

createL2CAPConnection

public static L2CAPConnection createL2CAPConnection(JSR82URL url)
                                             throws java.lang.Exception

Creates a new L2CAP connection with a remote BT device. All connection parameters (receiveMTU, transmitMTU,..etc..) are encapsulated in the connection URL.

Parameters:

url - The connection URL

Returns:

An instance of L2CAPConnection if the establishment of the connection did succeed.

Throws:

java.lang.Exception

getTransmitMTU

public int getTransmitMTU()
                   throws java.io.IOException

Returns the MTU that the remote device supports. This value is obtained after the connection has been configured. If the application had specified TransmitMTU in the Connector.open() string then this value should be equal to that. If the application did not specify any TransmitMTU, then this value should be less than or equal to the ReceiveMTU the remote device advertised during channel configuration.

Specified by:

getTransmitMTU in interface L2CAPConnection

Returns:

the maximum number of bytes that can be sent in a single call to send() without losing any data

Throws:

java.io.IOException - if the connection is closed

getReceiveMTU

public int getReceiveMTU()
                  throws java.io.IOException

Returns the ReceiveMTU that the connection supports. If the connection string did not specify a ReceiveMTU, the value returned will be less than or equal to the DEFAULT_MTU. Also, if the connection string did specify an MTU, this value will be less than or equal to the value specified in the connection string.

Specified by:

getReceiveMTU in interface L2CAPConnection

Returns:

the maximum number of bytes that can be read in a single call to receive()

Throws:

java.io.IOException - if the connection is closed

receive

public int receive(byte[] inBuf)
            throws java.io.IOException,
                   java.lang.NullPointerException

Reads a packet of data. The amount of data received in this operation is related to the value of ReceiveMTU. If the size of inBuf is greater than or equal to ReceiveMTU, then no data will be lost. Unlike read() on an java.io.InputStream, if the size of inBuf is smaller than ReceiveMTU, then the portion of the L2CAP payload that will fit into inBuf will be placed in inBuf, the rest will be discarded. If the application is aware of the number of bytes (less than ReceiveMTU) it will receive in any transaction, then the size of inBuf can be less than ReceiveMTU and no data will be lost. If inBuf is of length 0, all data sent in one packet is lost unless the length of the packet is 0.

Specified by:

receive in interface L2CAPConnection

Parameters:

inBuf - byte array to store the received data

Returns:

the actual number of bytes read; 0 if a zero length packet is received; 0 if inBuf length is zero

Throws:

java.io.IOException - if an I/O error occurs or the connection has been closed

java.io.InterruptedIOException - if the request timed out

java.lang.NullPointerException - if inBuf is null

ready

public boolean ready()
              throws java.io.IOException

Determines if there is a packet that can be read via a call to receive(). If true, a call to receive() will not block the application.

Specified by:

ready in interface L2CAPConnection

Returns:

true if there is data to read; false if there is no data to read

Throws:

java.io.IOException - if the connection is closed

See Also:

receive(byte[])

send

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

Requests that data be sent to the remote device. The TransmitMTU determines the amount of data that can be successfully sent in a single send operation. If the size of data is greater than the TransmitMTU, then only the first TransmitMTU bytes of the packet are sent, and the rest will be discarded. If data is of length 0, an empty L2CAP packet will be sent.

Specified by:

send in interface L2CAPConnection

Parameters:

data - data to be sent

Throws:

java.io.IOException - if data cannot be sent successfully or if the connection is closed

java.lang.NullPointerException - if the data is null