Added in API level 5

BluetoothServerSocket

public final class BluetoothServerSocket
extends Object implements Closeable

java.lang.Object
   ↳ android.bluetooth.BluetoothServerSocket


A listening Bluetooth socket.

The interface for Bluetooth Sockets is similar to that of TCP sockets: Socket and ServerSocket. On the server side, use a BluetoothServerSocket to create a listening server socket. When a connection is accepted by the BluetoothServerSocket, it will return a new BluetoothSocket to manage the connection. On the client side, use a single BluetoothSocket to both initiate an outgoing connection and to manage the connection.

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 BluetoothServerSocket that's ready for incoming Bluetooth BR/EDR connections, use BluetoothAdapter.listenUsingRfcommWithServiceRecord().

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 BluetoothAdapter.listenUsingL2capChannel() to create a listening BluetoothServerSocket that's ready for incoming Bluetooth LE CoC connections. For LE CoC, you can use getPsm() to get the protocol/service multiplexer (PSM) value that the peer needs to use to connect to your socket.

After the listening BluetoothServerSocket is created, call accept() to listen for incoming connection requests. This call will block until a connection is established, at which point, it will return a BluetoothSocket to manage the connection. Once the BluetoothSocket is acquired, it's a good idea to call close() on the BluetoothServerSocket when it's no longer needed for accepting connections. Closing the BluetoothServerSocket will not close the returned BluetoothSocket.

BluetoothServerSocket is thread safe. In particular, close() will always immediately abort ongoing operations and close the server socket.

Developer Guides

For more information about using Bluetooth, read the Bluetooth developer guide.

See also:

Summary

Public methods

BluetoothSocket accept()

Block until a connection is established.

BluetoothSocket accept(int timeout)

Block until a connection is established, with timeout.

void close()

Immediately close this socket, and release all associated resources.

int getPsm()

Returns the assigned dynamic protocol/service multiplexer (PSM) value for the listening L2CAP Connection-oriented Channel (CoC) server socket.

String toString()

Returns a string representation of the object.

Inherited methods

Public methods

accept

Added in API level 5
public BluetoothSocket accept ()

Block until a connection is established.

Returns a connected BluetoothSocket on successful connection.

Once this call returns, it can be called again to accept subsequent incoming connections.

close() can be used to abort this call from another thread.

Returns
BluetoothSocket a connected BluetoothSocket

Throws
IOException on error, for example this call was aborted, or timeout

accept

Added in API level 5
public BluetoothSocket accept (int timeout)

Block until a connection is established, with timeout.

Returns a connected BluetoothSocket on successful connection.

Once this call returns, it can be called again to accept subsequent incoming connections.

close() can be used to abort this call from another thread.

Parameters
timeout int

Returns
BluetoothSocket a connected BluetoothSocket

Throws
IOException on error, for example this call was aborted, or timeout

close

Added in API level 5
public void close ()

Immediately close this socket, and release all associated resources.

Causes blocked calls on this socket in other threads to immediately throw an IOException.

Closing the BluetoothServerSocket will not close any BluetoothSocket received from accept().

Throws
IOException

getPsm

Added in API level 29
public int getPsm ()

Returns the assigned dynamic protocol/service multiplexer (PSM) value for the listening L2CAP Connection-oriented Channel (CoC) server socket. This server socket must be returned by the BluetoothAdapter#listenUsingL2capChannel() or BluetoothAdapter.listenUsingInsecureL2capChannel(). The returned value is undefined if this method is called on non-L2CAP server sockets.

Returns
int the assigned PSM or LE_PSM value depending on transport

toString

Added in API level 5
public String toString ()

Returns a string representation of the object.

Returns
String a string representation of the object.