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Provides classes that manage Bluetooth functionality, such as scanning for
devices, connecting with devices, and managing data transfer between devices.
<p>The Bluetooth APIs let applications:</p>
<ul>
<li>Scan for other Bluetooth devices</li>
<li>Query the local Bluetooth adapter for paired Bluetooth devices</li>
<li>Establish RFCOMM channels/sockets</li>
<li>Connect to specified sockets on other devices</li>
<li>Transfer data to and from other devices</li>
</ul>
<p class="note"><strong>Note:</strong>
To perform Bluetooth communication using these APIs, an application must
declare the {@link android.Manifest.permission#BLUETOOTH} permission. Some
additional functionality, such as requesting device discovery and
pairing also requires the {@link android.Manifest.permission#BLUETOOTH_ADMIN}
permission.
</p>
<h3>Overview</h3>
<p>Here's a basic introduction to the Bluetooth classes:</p>
<dl>
<dt>{@link android.bluetooth.BluetoothAdapter}</dt>
<dd>This represents the local Bluetooth adapter, which is essentially the
entry-point to performing any interaction with Bluetooth. With it, you can
discover other Bluetooth devices, query a list of bonded (paired) devices,
initialize a {@link android.bluetooth.BluetoothDevice} using a known MAC
address, and create a {@link android.bluetooth.BluetoothServerSocket} to
listen for communications from other devices.</dd>
<dt>{@link android.bluetooth.BluetoothDevice}</dt>
<dd>This represents a remote Bluetooth device. Use this to request a
connection with a remote device through a
{@link android.bluetooth.BluetoothSocket}
or query information about the device such as its name, address, class, and
bonding state.</dd>
<dt>{@link android.bluetooth.BluetoothSocket}</dt>
<dd>This represents the interface for a Bluetooth socket
(similar to a TCP client-side {@link java.net.Socket}). This is the
connection point that allows an app to transfer data with another Bluetooth
device via {@link java.io.InputStream} and {@link java.io.OutputStream}.</dd>
<dt>{@link android.bluetooth.BluetoothServerSocket}</dt>
<dd>This represents an open server socket that listens for incoming requests
(similar to a TCP server-side {@link java.net.ServerSocket}).
When attempting to connect two Android devices, one device will need to open
a server socket with this class. When a connection is accepted, a new
{@link android.bluetooth.BluetoothSocket} will be returned,
which can be used to manage the connection and transfer data.</dd>
<dt>{@link android.bluetooth.BluetoothClass}</dt>
<dd>This represents the Bluetooth class for a device which describes general
characteristics and capabilities of a device. This class and its subclasses
don't provide any actual functionality. The sub-classes are entirely composed
of constants for the device and service class definitions.</dd>
</dl>
<h3>Example Procedure</h3>
<p>For example, here's an pseudo-code procedure for discovering and
connecting a remote device, and transfering data:</p>
<ol>
<li>Register a {@link android.content.BroadcastReceiver} that accepts the
{@link android.bluetooth.BluetoothDevice#ACTION_FOUND} Intent.</li>
<li>Call {@link android.bluetooth.BluetoothAdapter#getDefaultAdapter} to
retrieve the Android system's local
{@link android.bluetooth.BluetoothAdapter}.</li>
<li>Call {@link android.bluetooth.BluetoothAdapter#startDiscovery()
BluetoothAdapter.startDiscovery()} to scan for local devices. This is where
the BroadcastReceiver comes in; Android now scans for devices and will
broadcast the {@link android.bluetooth.BluetoothDevice#ACTION_FOUND} Intent
for each remote device discovered. The
{@link android.content.BroadcastReceiver}
you created will receive each Intent.</li>
<li>The {@link android.bluetooth.BluetoothDevice#ACTION_FOUND} Intent
includes the {@link android.bluetooth.BluetoothDevice#EXTRA_DEVICE}
Parcelable extra, which is a {@link android.bluetooth.BluetoothDevice}
object. Extract this from the Intent and call
{@link android.bluetooth.BluetoothDevice#createRfcommSocketToServiceRecord(java.util.UUID)
BluetoothDevice.createRfcommSocketToServiceRecord()}
to open a {@link android.bluetooth.BluetoothSocket} with a chosen
remote device.</li>
<li>Call {@link android.bluetooth.BluetoothSocket#connect()
BluetoothSocket.connect()} to connect with the remote device.</li>
<li>When successfully connected, call
{@link android.bluetooth.BluetoothSocket#getInputStream()
BluetoothSocket.getInputStream()} and/or
{@link android.bluetooth.BluetoothSocket#getOutputStream()
BluetoothSocket.getOutputStream()} to retreive an
{@link java.io.InputStream} and {@link java.io.OutputStream}, respectively,
which are hooked into the socket.</li>
<li>Use {@link java.io.InputStream#read(byte[]) InputStream.read()} and
{@link java.io.OutputStream#write(byte[]) OutputStream.write()} to transfer
data.</li>
</ol>
<p class="note"><strong>Note:</strong>
Not all Android devices are guaranteed to have Bluetooth functionality.</p>
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