Android
Bluetooth och Bluetooth LE API

Anmärkningar

Behörigheter

Lägg till denna behörighet till manifestfilen för att använda Bluetooth-funktioner i din applikation:

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

Om du behöver initiera enhetsupptäckt eller manipulera Bluetooth-inställningar måste du också lägga till denna behörighet:

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

Inriktning på Android API-nivå 23 och högre kräver platsåtkomst:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<!-- OR -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

* Se även Behörigheter ämne för mer information om hur man använder behörigheter på lämpligt sätt.

Kontrollera om Bluetooth är aktiverat

private static final int REQUEST_ENABLE_BT = 1; // Unique request code
BluetoothAdapter mBluetoothAdapter;

// ...

if (!mBluetoothAdapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}

// ...

@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == REQUEST_ENABLE_BT) {
        if (resultCode == RESULT_OK) {
            // Bluetooth was enabled
        } else if (resultCode == RESULT_CANCELED) {
            // Bluetooth was not enabled
        }
    }
}

Gör enheten upptäckbar

private static final int REQUEST_DISCOVERABLE_BT = 2; // Unique request code
private static final int DISCOVERABLE_DURATION = 120; // Discoverable duration time in seconds
                                                      // 0 means always discoverable
                                                      // maximum value is 3600

// ...

Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, DISCOVERABLE_DURATION);
startActivityForResult(discoverableIntent, REQUEST_DISCOVERABLE_BT);

// ...

@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == REQUEST_DISCOVERABLE_BT) {
        if (resultCode == RESULT_OK) {
            // Device is discoverable
        } else if (resultCode == RESULT_CANCELED) {
            // Device is not discoverable
        }
    }
}

Hitta Bluetooth-enheter i närheten

Förklara en BluetoothAdapter först.

BluetoothAdapter mBluetoothAdapter;

ACTION_FOUND nu en BroadcastReceiver för ACTION_FOUND

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
    String action = intent.getAction();

    //Device found                
    if (BluetoothDevice.ACTION_FOUND.equals(action)) 
    {
        // Get the BluetoothDevice object from the Intent
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        // Add the name and address to an array adapter to show in a list
        mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
    }
  }
};

Registrera BroadcastReceiver

IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);

Börja sedan upptäcka de närliggande Bluetooth-enheterna genom att ringa startDiscovery

mBluetoothAdapter.startDiscovery(); 

Glöm inte att avregistrera BroadcastReceiver onDestroy

unregisterReceiver(mReceiver);

Anslut till Bluetooth-enhet

När du har fått BluetoothDevice kan du kommunicera med den. Den här typen av kommunikation utförs med hjälp av socket input / output-strömmar:

Dessa är de grundläggande stegen för etablering av Bluetooth-kommunikation:

1) Initiera uttaget:

 private BluetoothSocket _socket;
 //...
 public InitializeSocket(BluetoothDevice device){
    try {
        _socket = device.createRfcommSocketToServiceRecord(<Your app UDID>);
    } catch (IOException e) {
        //Error
    }
  }

2) Anslut till uttaget:

try {
    _socket.connect();
} catch (IOException connEx) {
    try {
        _socket.close();
    } catch (IOException closeException) {
        //Error
    }
}

if (_socket != null && _socket.isConnected()) {
    //Socket is connected, now we can obtain our IO streams
}

3) Skaffa socket Input \ Output-strömmar

private InputStream _inStream;
private OutputStream _outStream;
//....
try {
    _inStream = _socket.getInputStream();
    _outStream =  _socket.getOutputStream();
} catch (IOException e) {
   //Error
}

Ingångsström - Används som inkommande datakanal (ta emot data från ansluten enhet)

Utgångsström - Används som utgående datakanal (skicka data till ansluten enhet)

Efter att ha avslutat tredje steget kan vi ta emot och skicka data mellan båda enheterna med tidigare initierade strömmar:

1) Mottagande av data (avläsning från socket-ingångsström)

byte[] buffer = new byte[1024];  // buffer (our data)
int bytesCount; // amount of read bytes

while (true) {
    try {
        //reading data from input stream
        bytesCount = _inStream.read(buffer);
        if(buffer != null && bytesCount > 0)
        {
            //Parse received bytes
        }
    } catch (IOException e) {
        //Error
    }
}

2) Skicka data (skriva till utgångsström)

public void write(byte[] bytes) {
    try {
        _outStream.write(bytes);
    } catch (IOException e) {
        //Error
    }
}

• Naturligtvis bör anslutnings-, läs- och skrivfunktioner göras i en dedicerad tråd.
• Sockets och Stream-objekt måste vara

Hitta närliggande Bluetooth Low Energy-enheter

BluetoothLE-API: et introducerades i API 18. Men sättet att skanna enheter har ändrats i API 21. Sökningen av enheter måste börja med att definiera tjänsten UUID som ska skannas (antingen officiellt antagna 16-bitars UUID: s eller proprietära) . Detta exempel illustrerar hur man gör ett API-oberoende sätt att söka efter BLE-enheter:

1. Skapa Bluetooth-enhetsmodell:

public class BTDevice {
    String address;
    String name;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

2. Definiera Bluetooth-skanningsgränssnitt:

public interface ScanningAdapter {

    void startScanning(String name, String[] uuids);
    void stopScanning();
    List<BTDevice> getFoundDeviceList();
}

3. Skapa fabriksklass för skanning:

public class BluetoothScanningFactory implements ScanningAdapter {

    private ScanningAdapter mScanningAdapter;

    public BluetoothScanningFactory() {
        if (isNewerAPI()) {
            mScanningAdapter = new LollipopBluetoothLEScanAdapter();
        } else {
            mScanningAdapter = new JellyBeanBluetoothLEScanAdapter();
        }
    }

    private boolean isNewerAPI() {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
    }

    @Override
    public void startScanning(String[] uuids) {
        mScanningAdapter.startScanning(uuids);
    }

    @Override
    public void stopScanning() {
        mScanningAdapter.stopScanning();
    }

    @Override
    public List<BTDevice> getFoundDeviceList() {
        return mScanningAdapter.getFoundDeviceList();
    }
}

4. Skapa fabriksimplementering för varje API:

API 18:

import android.annotation.TargetApi;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.os.Build;
import android.os.Parcelable;
import android.util.Log;

import bluetooth.model.BTDevice;

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
public class JellyBeanBluetoothLEScanAdapter implements ScanningAdapter{
    BluetoothAdapter bluetoothAdapter;
    ScanCallback mCallback;

    List<BTDevice> mBluetoothDeviceList;

    public JellyBeanBluetoothLEScanAdapter() {
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        mCallback = new ScanCallback();
        mBluetoothDeviceList = new ArrayList<>();
    }

    @Override
    public void startScanning(String[] uuids) {
        if (uuids == null || uuids.length == 0) {
            return;
        }
        UUID[] uuidList = createUUIDList(uuids);
        bluetoothAdapter.startLeScan(uuidList, mCallback);
    }

    private UUID[] createUUIDList(String[] uuids) {
        UUID[] uuidList = new UUID[uuids.length];
        for (int i = 0 ; i < uuids.length ; ++i) {
            String uuid = uuids[i];
            if (uuid == null) {
                continue;
            }
            uuidList[i] = UUID.fromString(uuid);
        }
        return uuidList;
    }

    @Override
    public void stopScanning() {
        bluetoothAdapter.stopLeScan(mCallback);
    }

    @Override
    public List<BTDevice> getFoundDeviceList() {
        return mBluetoothDeviceList;
    }

    private class ScanCallback implements BluetoothAdapter.LeScanCallback {

        @Override
        public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
            if (isAlreadyAdded(device)) {
                return;
            }
            BTDevice btDevice = new BTDevice();
            btDevice.setName(new String(device.getName()));
            btDevice.setAddress(device.getAddress());
            mBluetoothDeviceList.add(btDevice);
            Log.d("Bluetooth discovery", device.getName() + " " + device.getAddress());
            Parcelable[] uuids = device.getUuids();
            String uuid = "";
            if (uuids != null) {
                for (Parcelable ep : uuids) {
                    uuid += ep + " ";
                }
                Log.d("Bluetooth discovery", device.getName() + " " + device.getAddress() + " " + uuid);
            }
        }

        private boolean isAlreadyAdded(BluetoothDevice bluetoothDevice) {
            for (BTDevice device : mBluetoothDeviceList) {
                String alreadyAddedDeviceMACAddress = device.getAddress();
                String newDeviceMACAddress = bluetoothDevice.getAddress();
                if (alreadyAddedDeviceMACAddress.equals(newDeviceMACAddress)) {
                    return true;
                }
            }
            return false;
        }
    }
}

API 21:

import android.annotation.TargetApi;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.le.BluetoothLeScanner;
import android.bluetooth.le.ScanFilter;
import android.bluetooth.le.ScanResult;
import android.bluetooth.le.ScanSettings;
import android.os.Build;
import android.os.ParcelUuid;

import bluetooth.model.BTDevice;

import java.util.ArrayList;
import java.util.List;

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public class LollipopBluetoothLEScanAdapter implements ScanningAdapter {
    BluetoothLeScanner bluetoothLeScanner;
    ScanCallback mCallback;

    List<BTDevice> mBluetoothDeviceList;

    public LollipopBluetoothLEScanAdapter() {
        bluetoothLeScanner = BluetoothAdapter.getDefaultAdapter().getBluetoothLeScanner();
        mCallback = new ScanCallback();
        mBluetoothDeviceList = new ArrayList<>();
    }

    @Override
    public void startScanning(String[] uuids) {
        if (uuids == null || uuids.length == 0) {
            return;
        }
        List<ScanFilter> filterList = createScanFilterList(uuids);
        ScanSettings scanSettings = createScanSettings();
        bluetoothLeScanner.startScan(filterList, scanSettings, mCallback);
    }

    private List<ScanFilter> createScanFilterList(String[] uuids) {
        List<ScanFilter> filterList = new ArrayList<>();
        for (String uuid : uuids) {
            ScanFilter filter = new ScanFilter.Builder()
                    .setServiceUuid(ParcelUuid.fromString(uuid))
                    .build();
            filterList.add(filter);
        };
        return filterList;
    }

    private ScanSettings createScanSettings() {
        ScanSettings settings = new ScanSettings.Builder()
                .setScanMode(ScanSettings.SCAN_MODE_BALANCED)
                .build();
        return settings;
    }

    @Override
    public void stopScanning() {
        bluetoothLeScanner.stopScan(mCallback);
    }

    @Override
    public List<BTDevice> getFoundDeviceList() {
        return mBluetoothDeviceList;
    }

    public class ScanCallback extends android.bluetooth.le.ScanCallback {

        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            super.onScanResult(callbackType, result);
            if (result == null) {
                return;
            }
            BTDevice device = new BTDevice();
            device.setAddress(result.getDevice().getAddress());
            device.setName(new StringBuffer(result.getScanRecord().getDeviceName()).toString());
            if (device == null || device.getAddress() == null) {
                return;
            }
            if (isAlreadyAdded(device)) {
                return;
            }
            mBluetoothDeviceList.add(device);
        }

        private boolean isAlreadyAdded(BTDevice bluetoothDevice) {
            for (BTDevice device : mBluetoothDeviceList) {
                String alreadyAddedDeviceMACAddress = device.getAddress();
                String newDeviceMACAddress = bluetoothDevice.getAddress();
                if (alreadyAddedDeviceMACAddress.equals(newDeviceMACAddress)) {
                    return true;
                }
            }
            return false;
        }
    }
}

5. Få listan över hittade enheter genom att ringa:

   scanningFactory.startScanning({uuidlist});
   
   wait few seconds...
   
   List<BTDevice> bluetoothDeviceList = scanningFactory.getFoundDeviceList();