Merge "Add more documentation for LE CoC"

 * returned by {@link BluetoothAdapter#getBondedDevices()

 * BluetoothAdapter.getBondedDevices()}. You can then open a

 * {@link BluetoothSocket} for communication with the remote device, using

 * {@link #createRfcommSocketToServiceRecord(UUID)}.

 * {@link #createRfcommSocketToServiceRecord(UUID)} over Bluetooth BR/EDR or using

 * {@link #createL2capChannel(int)} over Bluetooth LE.

 *

 * <p class="note"><strong>Note:</strong>

 * Requires the {@link android.Manifest.permission#BLUETOOTH} permission.

 * On the client side, use a single {@link BluetoothSocket} to both initiate

 * an outgoing connection and to manage the connection.

 *

 * <p>The most common type of Bluetooth socket is RFCOMM, which is the type

 * supported by the Android APIs. RFCOMM is a connection-oriented, streaming

 * transport over Bluetooth. It is also known as the Serial Port Profile (SPP).

 * <p>For Bluetooth BR/EDR, the most common type of socket is RFCOMM, which is the type supported by

 * the Android APIs. RFCOMM is a connection-oriented, streaming transport over Bluetooth BR/EDR. It

 * is also known as the Serial Port Profile (SPP). To create a listening

 * {@link BluetoothServerSocket} that's ready for incoming Bluetooth BR/EDR connections, use {@link

 * BluetoothAdapter#listenUsingRfcommWithServiceRecord

 * BluetoothAdapter.listenUsingRfcommWithServiceRecord()}.

 *

 * <p>To create a listening {@link BluetoothServerSocket} that's ready for

 * incoming connections, use

 * {@link BluetoothAdapter#listenUsingRfcommWithServiceRecord

 * BluetoothAdapter.listenUsingRfcommWithServiceRecord()}. Then call

 * {@link #accept()} to listen for incoming connection requests. This call

 * will block until a connection is established, at which point, it will return

 * a {@link BluetoothSocket} to manage the connection. Once the {@link

 * BluetoothSocket} is acquired, it's a good idea to call {@link #close()} on

 * the {@link BluetoothServerSocket} when it's no longer needed for accepting

 * connections. Closing the {@link BluetoothServerSocket} will <em>not</em>

 * close the returned {@link BluetoothSocket}.

 * <p>For Bluetooth LE, the socket uses LE Connection-oriented Channel (CoC). LE CoC is a

 * connection-oriented, streaming transport over Bluetooth LE and has a credit-based flow control.

 * Correspondingly, use {@link BluetoothAdapter#listenUsingL2capChannel

 * BluetoothAdapter.listenUsingL2capChannel()} to create a listening {@link BluetoothServerSocket}

 * that's ready for incoming Bluetooth LE CoC connections. For LE CoC, you can use {@link #getPsm()}

 * to get the protocol/service multiplexer (PSM) value that the peer needs to use to connect to your

 * socket.

 *

 * <p> After the listening {@link BluetoothServerSocket} is created, call {@link #accept()} to

 * listen for incoming connection requests. This call will block until a connection is established,

 * at which point, it will return a {@link BluetoothSocket} to manage the connection. Once the

 * {@link BluetoothSocket} is acquired, it's a good idea to call {@link #close()} on the {@link

 * BluetoothServerSocket} when it's no longer needed for accepting

 * connections. Closing the {@link BluetoothServerSocket} will <em>not</em> close the returned

 * {@link BluetoothSocket}.

 *

 * <p>{@link BluetoothServerSocket} is thread

 * safe. In particular, {@link #close} will always immediately abort ongoing