public final class BluetoothSocket extends Object implements Closeable
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.
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).
To create a BluetoothSocket
for connecting to a known device, use
BluetoothDevice.createRfcommSocketToServiceRecord()
.
Then call connect()
to attempt a connection to the remote device.
This call will block until a connection is established or the connection
fails.
To create a BluetoothSocket
as a server (or "host"), see the
BluetoothServerSocket
documentation.
Once the socket is connected, whether initiated as a client or accepted
as a server, open the IO streams by calling getInputStream()
and
getOutputStream()
in order to retrieve InputStream
and OutputStream
objects, respectively, which are
automatically connected to the socket.
BluetoothSocket
is thread
safe. In particular, close()
will always immediately abort ongoing
operations and close the socket.
Note:
Requires the android.Manifest.permission#BLUETOOTH
permission.
For more information about using Bluetooth, read the Bluetooth developer guide.
BluetoothServerSocket
InputStream
OutputStream
Modifier and Type | Field and Description |
---|---|
static int |
MAX_RFCOMM_CHANNEL |
static int |
TYPE_L2CAP
L2CAP socket
|
static int |
TYPE_RFCOMM
RFCOMM socket
|
static int |
TYPE_SCO
SCO socket
|
Modifier and Type | Method and Description |
---|---|
void |
close()
Closes this stream and releases any system resources associated
with it.
|
void |
connect()
Attempt to connect to a remote device.
|
protected void |
finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
|
int |
getConnectionType()
Get the type of the underlying connection.
|
InputStream |
getInputStream()
Get the input stream associated with this socket.
|
int |
getMaxReceivePacketSize()
Get the maximum supported Receive packet size for the underlying transport.
|
int |
getMaxTransmitPacketSize()
Get the maximum supported Transmit packet size for the underlying transport.
|
OutputStream |
getOutputStream()
Get the output stream associated with this socket.
|
BluetoothDevice |
getRemoteDevice()
Get the remote device this socket is connecting, or connected, to.
|
boolean |
isConnected()
Get the connection status of this socket, ie, whether there is an active connection with
remote device.
|
void |
setExcludeSdp(boolean excludeSdp)
Change if a SDP entry should be automatically created.
|
public static final int MAX_RFCOMM_CHANNEL
public static final int TYPE_RFCOMM
public static final int TYPE_SCO
public static final int TYPE_L2CAP
protected void finalize() throws Throwable
Object
finalize
method to dispose of
system resources or to perform other cleanup.
The general contract of finalize
is that it is invoked
if and when the JavaTM virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize
method may take any action, including
making this object available again to other threads; the usual purpose
of finalize
, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize
method of class Object
performs no
special action; it simply returns normally. Subclasses of
Object
may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize
method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize
method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize
method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
public BluetoothDevice getRemoteDevice()
public InputStream getInputStream() throws IOException
The input stream will be returned even if the socket is not yet connected, but operations on that stream will throw IOException until the associated socket is connected.
IOException
public OutputStream getOutputStream() throws IOException
The output stream will be returned even if the socket is not yet connected, but operations on that stream will throw IOException until the associated socket is connected.
IOException
public boolean isConnected()
public void connect() throws IOException
This method will block until a connection is made or the connection fails. If this method returns without an exception then this socket is now connected.
Creating new connections to
remote Bluetooth devices should not be attempted while device discovery
is in progress. Device discovery is a heavyweight procedure on the
Bluetooth adapter and will significantly slow a device connection.
Use BluetoothAdapter.cancelDiscovery()
to cancel an ongoing
discovery. Discovery is not managed by the Activity,
but is run as a system service, so an application should always call
BluetoothAdapter.cancelDiscovery()
even if it
did not directly request a discovery, just to be sure.
close()
can be used to abort this call from another thread.
IOException
- on error, for example connection failurepublic void close() throws IOException
Closeable
close
in interface Closeable
close
in interface AutoCloseable
IOException
- if an I/O error occurspublic int getMaxTransmitPacketSize()
public int getMaxReceivePacketSize()
public int getConnectionType()
TYPE_RFCOMM
, TYPE_SCO
or TYPE_L2CAP
public void setExcludeSdp(boolean excludeSdp)
mExcludeSdp
-