Types of Bluetooth Connections

All of the Bluetooth APIs are available in the android.bluetoothpackage. Here's a summary of the classes and interfaces you will need to create Bluetooth connections:

BluetoothAdapter

Represents the local Bluetooth adapter (Bluetooth radio). The BluetoothAdapter is the entry-point for all Bluetooth interaction. Using this, you can discover other Bluetooth devices, query a list of bonded (paired) devices, instantiate a BluetoothDevice using a known MAC address, and create aBluetoothServerSocket to listen for communications from other devices.

BluetoothDevice

Represents a remote Bluetooth device. Use this to request a connection with a remote device through aBluetoothSocket or query information about the device such as its name, address, class, and bonding state.

BluetoothSocket

Represents the interface for a Bluetooth socket (similar to a TCP Socket). This is the connection point that allows an application to exchange data with another Bluetooth device via InputStream and OutputStream.

BluetoothServerSocket

Represents an open server socket that listens for incoming requests (similar to a TCP ServerSocket). In order to connect two Android devices, one device must open a server socket with this class. When a remote Bluetooth device makes a connection request to the this device, the BluetoothServerSocket will return a connected BluetoothSocket when the connection is accepted.

BluetoothClass

Describes the general characteristics and capabilities of a Bluetooth device. This is a read-only set of properties that define the device's major and minor device classes and its services. However, this does not reliably describe all Bluetooth profiles and services supported by the device, but is useful as a hint to the device type.

BluetoothProfile

An interface that represents a Bluetooth profile. A Bluetooth profile is a wireless interface specification for Bluetooth-based communication between devices. An example is the Hands-Free profile. 

BluetoothHeadset

Provides support for Bluetooth headsets to be used with mobile phones. This includes both Bluetooth Headset and Hands-Free (v1.5) profiles.

BluetoothA2dp

Defines how high quality audio can be streamed from one device to another over a Bluetooth connection. "A2DP" stands for Advanced Audio Distribution Profile.

BluetoothHealth

Represents a Health Device Profile proxy that controls the Bluetooth service.

BluetoothHealthCallback

An abstract class that you use to implement BluetoothHealth callbacks. You must extend this class and implement the callback methods to receive updates about changes in the application’s registration state and Bluetooth channel state.

BluetoothHealthAppConfiguration

Represents an application configuration that the Bluetooth Health third-party application registers to communicate with a remote Bluetooth health device.

BluetoothProfile.ServiceListener

An interface that notifies BluetoothProfile IPC clients when they have been connected to or disconnected from the service (that is, the internal service that runs a particular profile)