Android-Bluetooth-Library

This is an Android bluetooth client server library for communication any device via bluetooth with Serial Port Profile (SPP). This library allows you to easily create a socket bluetooth connection for two devices with one server and one client. The main purpose of this library is you can establish connection in one Class or Activity or Fragment and can send or receive data in multiple Classes / Activities / Fragments. This library is compatible with the Android SDK 4.4 W to up.

Bluetooth Classic app uses Android-Bluetooth-Library.

Features

Support Android 12

Bluetooth class provides the following features :

• Turn on/ off bluetooth.
• Detect nearby bluetooth devices.
• Get bluetooth discovery started or finished.
• Pair bluetooth device and list of paired devices.
• Unpair bluetooth device (using reflection).

Connection class provides the following features :

• Set your own UUID for connection.
• Accept incoming bluetooth connection request.
• Connect bluetooth device.
• Received data from connected device.
• Send data to connected device.
• Check connection status.
• Disconnect bluetooth connection.

SendReceive class provides the following features:

• Send data to connected device (using one or more Classes / Activities / Fragments).
• Receive data from connected device (using one or more Classes / Activities / Fragments).

Version 0.2

New feature added in Connection class

• Connect timeout

Enable and disable connect timeout

// Enable
connection.enableConnectTimeout();
// Disable
connection.disableConnectTimeout();

Set your own connect timeout (Optional)

Default connect timeout is 35 sec.

connection.setConnectTimeout(timeoutMillis);

Quick start

Add JitPack to your root build.gradle at the end of repositories:

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

Add the dependency in your module build.gradle:

dependencies {
  implementation 'com.github.prasad-psp:Android-Bluetooth-Library:1.0.2'
}

Permissions

Target Android 12 or higher

<uses-permission
        android:name="android.permission.BLUETOOTH"
        android:maxSdkVersion="30" />
<uses-permission
        android:name="android.permission.BLUETOOTH_ADMIN"
        android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
        android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
        android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN"
        android:usesPermissionFlags="neverForLocation"
        tools:targetApi="s" />

Target Android 11 or lower

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Read more Android Bluetooth Permissions.

Bluetooth

Turn on/off bluetooth

@Override
protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);

 	// Initialize bluetooth 
	bluetooth = new Bluetooth(this);
	
	// Turn on bluetooth with user permission 
	/* if you want to check user allow or denied bluetooth turn on 	
       	request add override method onActivityResult and request code is Bluetooth.BLUETOOTH_ENABLE_REQUEST */
	bluetooth.turnOnWithPermission(this);

	// Turn on bluetooth without user permission
	// bluetooth.turnOnWithoutPermission();

	// Turn off bluetooth
	bluetooth.turnOff();
}

Stop bluetooth service

@Override
protected void onStop() {
    bluetooth.onStop();
}

Detect nearby bluetooth devices

// Listener
bluetooth.setOnDetectNearbyDeviceListener(new BluetoothListener.onDetectNearbyDeviceListener() {
    @Override
    public void onDeviceDetected(BluetoothDevice device) {
        // Device found
	 Log.d(TAG, "Device found "+device.getName());
    }
});

bluetooth.startDetectNearbyDevices();

Bluetooth device discovery

// Listener
bluetooth.setOnDiscoveryStateChangedListener(new BluetoothListener.onDiscoveryStateChangedListener() {
    @Override
    public void onDiscoveryStateChanged(int state) {
        if(state == Bluetooth.DISCOVERY_STARTED) {
            Log.d(TAG,"Discovery started");
        }

        if(state == Bluetooth.DISCOVERY_FINISHED) {
            Log.d(TAG,"Discovery finished");
        }
    }
});

Pair bluetooth device and List of paired devices

// Listener
bluetooth.setOnDevicePairListener(new BluetoothListener.onDevicePairListener() {
    @Override
    public void onDevicePaired(BluetoothDevice device) {
	// Paired successful
        Log.d(TAG,device.getName()+" Paired successful");
    }

    @Override
    public void onCancelled(BluetoothDevice device) {
	// Pairing failed
        Log.d(TAG,device.getName()+" Pairing failed");
    }
});

// bluetooth.requestPairDevice(bluetoothDevice);
// OR
if(bluetooth.requestPairDevice(deviceAddress)) {
     // Pair request send successfully
     Log.d(TAG,"Pair request send successfully");
}

// List of paired devices
ArrayList<BluetoothDevice> devices = bluetooth.getPairedDevices();

Unpair bluetooth device (using reflaction)

// bluetooth.unpairDevice(bluetoothDevice);
// OR
if(bluetooth.unpairDevice(deviceAddress)) {
    Log.d(TAG,"Unpair successfully");
}
else {
    Log.d(TAG,"Unpair failed");
}

Connection

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); 
	// Initialize connection 
    	connection = new Connection(this);
}

Set your own UUID for connection (Optional)

Default UUID is 00001101-0000-1000-8000-00805F9B34FB

connection.setUUID(your_uuid);

As Server

Accept incoming bluetooth connection request

connection.accept(isSecureConnection,connectionListener, receiveListener);

// Connection Listener
private final BluetoothListener.onConnectionListener connectionListener = new BluetoothListener.onConnectionListener() {
    @Override
    public void onConnectionStateChanged(BluetoothSocket socket, int state) {
        switch (state) {
            case Connection.START_LISTENING: {
                Log.d(TAG,"Start Listening..."); 
                break;
            }

            case Connection.CONNECTED: {
                Log.d(TAG,"Connected");
                break;
            }

            case Connection.DISCONNECTED: {
                Log.d(TAG,"Disconnected");
		 // make sure call after detect bluetooth device disconnected   
		 connection.disconnect();
                break;
            }
        }
    }

    @Override
    public void onConnectionFailed(int errorCode) {
        switch (errorCode) {
            case Connection.SERVER_SOCKET_NOT_FOUND: {
                Log.d(TAG,"Server socket not found");
 		break;
            }

            case Connection.ACCEPT_FAILED: {
                Log.d(TAG,"Accept failed");
                break;
            }
        }

	// make sure call after detect onConnectionFailed
        connection.disconnect();
    }
};

As Client

Connect bluetooth device

// connection.connect(bluetoothDevice, isSecureConnection,connectionListener,receiveListener);
// OR
connection.connect(deviceAddress,isSecureConnection,connectionListener,receiveListener);

// Connection Listener
private final BluetoothListener.onConnectionListener connectionListener = new BluetoothListener.onConnectionListener() {
    @Override
    public void onConnectionStateChanged(BluetoothSocket socket, int state) {
        switch (state) {
            case Connection.CONNECTING: {
                Log.d(TAG,"Connecting..."); 
                break;
            }
	     case Connection.CONNECTED: {
                Log.d(TAG,"Connected");
                break;
            }
	     case Connection.DISCONNECTED: {
                Log.d(TAG,"Disconnected");
	        // make sure call after detect bluetooth device disconnected
		connection.disconnect();
	       break;
            }
        }
    }

    @Override
    public void onConnectionFailed(int errorCode) {
        switch (errorCode) {
            case Connection.SOCKET_NOT_FOUND: {
                Log.d(TAG,"Socket not found");
                break;
            }
	     case Connection.CONNECT_FAILED: {
                Log.d(TAG,"Connect Failed");
                break;
            }
        }
	// make sure call after detect onConnectionFailed
       connection.disconnect();
    }
};

Receive data from connected device

// Receive listener
private final BluetoothListener.onReceiveListener receiveListener = new BluetoothListener.onReceiveListener() {
    @Override
    public void onReceived(String receivedData) {
        Log.d(TAG,receivedData); 
    }
};

// Optional this will work when you will deal with multiple activities or fragments or classes
//connection.setOnReceiveListener(receiveListener);

Send data to connected device

// connection.send(b);  // byte[] b
// connection.send(b,off,len);   //byte[] b , int off, int len
// OR
if(connection.send(data)) {
    Log.d(TAG,"Send successful");
}
else {
    Log.d(TAG,"Sending failed");
}

Check connection status

if(connection.isConnected()) {
    Log.d(TAG,"Device connected");
}
else {
    Log.d(TAG,"Device disconnected");
}

Disconnect bluetooth connection

connection.disconnect();

Send Receive

Note: Call SendReceive class when connection is established.

Send data to connected device (using one or more Classes / Activities / Fragments)

// SendReceive.getInstance().send(b);  //byte[] b
// SendReceive.getInstance().send(b,off,len);  // byte[] b , int off, int len
// OR
if(SendReceive.getInstance().send(data)) {
    Log.d(TAG,"Send successful");
}
else {
    Log.d(TAG,"Sending failed");
}

Receive data from connected device (using one or more Classes / Activities / Fragments)

// Receive listener
SendReceive.getInstance().setOnReceiveListener(new BluetoothListener.onReceiveListener() {
    @Override
    public void onReceived(String receivedData) {
        Log.d(TAG, receivedData);
    }
});

Complete example

See the sample project.

Licence

MIT License
*
* Copyright (c) 2021 Prasad Parshram

See the full licence file.

Feedback

If you have any feedback, please reach out to us at [email protected]