10分钟完成一个最最简单的BLE蓝牙接收数据的DEMO

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

import android.bluetooth.BluetoothAdapter;import android.bluetooth.BluetoothDevice;import android.bluetooth.BluetoothGatt;import android.bluetooth.BluetoothGattCallback;import android.bluetooth.BluetoothGattCharacteristic;import android.bluetooth.BluetoothGattDescriptor;import android.bluetooth.BluetoothGattService;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.widget.Toast;
import java.util.List;import java.util.Set;import java.util.UUID;
public class MainActivity extends AppCompatActivity {    private BluetoothAdapter adapter;    private BluetoothGatt bluetoothGatt;
    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        openBlueToothLe();    }
    //打开蓝牙    private void openBlueToothLe() {        adapter = BluetoothAdapter.getDefaultAdapter();        if (null == adapter) {            Toast.makeText(this, "没有蓝牙功能", Toast.LENGTH_SHORT).show();            return;        }        if (!adapter.isEnabled()) {            adapter.enable();        }        startScan();    }
    //开始扫描    private void startScan() {        Set<BluetoothDevice> bondedDevices = adapter.getBondedDevices();        for (BluetoothDevice bondedDevice : bondedDevices) {            if ("你想要接收数据的已配对设备名称".equals(bondedDevice.getName().trim())) {                connectDevice(bondedDevice);            }        }    }
    //连接设备    private void connectDevice(BluetoothDevice bondedDevice) {        bluetoothGatt = bondedDevice.connectGatt(this, false, new BluetoothGattCallback() {            @Override            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {                super.onConnectionStateChange(gatt, status, newState);                if (BluetoothGatt.STATE_CONNECTED == newState) {                    bluetoothGatt = gatt;                    gatt.discoverServices();                } else if (BluetoothGatt.STATE_DISCONNECTED == newState) {                    gatt.close();                }            }
            @Override            public void onServicesDiscovered(BluetoothGatt gatt, int status) {                super.onServicesDiscovered(gatt, status);                List<BluetoothGattService> services = gatt.getServices();                for (BluetoothGattService service : services) {                    List<BluetoothGattCharacteristic> characteristics = service.getCharacteristics();                    for (BluetoothGattCharacteristic character : characteristics) {                        enableNotification(gatt, service.getUuid(), character.getUuid());                    }                }            }
            @Override            public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {                super.onCharacteristicChanged(gatt, characteristic);                byte[] value = characteristic.getValue();                Log.i("BLE", "receive value ----------------------------");                for (int i = 0; i < value.length; i++) {                    Log.i("BLE", "character_value = " + value[i]);                }            }        });    }
    @Override    protected void onDestroy() {        super.onDestroy();        bluetoothGatt.disconnect();    }
    public boolean enableNotification(BluetoothGatt gatt, UUID serviceUUID, UUID characteristicUUID) {        boolean success = false;        BluetoothGattService service = gatt.getService(serviceUUID);        if (service != null) {            BluetoothGattCharacteristic characteristic = findNotifyCharacteristic(service, characteristicUUID);            if (characteristic != null) {                success = gatt.setCharacteristicNotification(characteristic, true);                if (success) {                    // 来源：http://stackoverflow.com/questions/38045294/oncharacteristicchanged-not-called-with-ble                    for (BluetoothGattDescriptor dp : characteristic.getDescriptors()) {                        if (dp != null) {                            if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_NOTIFY) != 0) {                                dp.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);                            } else if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_INDICATE) != 0) {                                dp.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);                            }                            gatt.writeDescriptor(dp);                        }                    }                }            }        }        return success;    }
    private BluetoothGattCharacteristic findNotifyCharacteristic(BluetoothGattService service, UUID characteristicUUID) {        BluetoothGattCharacteristic characteristic = null;        List<BluetoothGattCharacteristic> characteristics = service.getCharacteristics();        for (BluetoothGattCharacteristic c : characteristics) {            if ((c.getProperties() & BluetoothGattCharacteristic.PROPERTY_NOTIFY) != 0                    && characteristicUUID.equals(c.getUuid())) {                characteristic = c;                break;            }        }        if (characteristic != null)            return characteristic;        for (BluetoothGattCharacteristic c : characteristics) {            if ((c.getProperties() & BluetoothGattCharacteristic.PROPERTY_INDICATE) != 0                    && characteristicUUID.equals(c.getUuid())) {                characteristic = c;                break;            }        }        return characteristic;    }}