Android 蓝牙BLE （蓝牙成长之路）3

关于蓝牙BLE最重要的 还是 service这块了（关于数据的传递，我也找到了一些demo 稍后为我们这些刚涉蓝牙BLE的菜鸟来个科普），我现在也是一知半解  先科普下（PS:我也是菜鸟中的菜鸟。。。写这个纯属加深印象。。。）下面的也是我翻遍了几乎网上少少半关于BLE的资料  整理下的（PS:网上关于BLE详解的 不多。。。个人觉的  还是要自己手打一遍  不要老是粘贴复制（PS：我通常都是ctrl+c ctrl+v））

在BLE协议中，有两个角色，周边（Periphery）和中央（Central），一个中央可以同时连接多个周边，但是一个周边某一时刻只能连接一个中央。但是不管是Periphery还是Central都是可以实现 GATT server 和 GATT client去传输数据，但是无法同时都是。

BLE分为三部分Service、Characteristic、Descriptor，这三部分都由UUID作为唯一标示符。一个蓝牙4.0的终端可以包含多个Service，一个Service可以包含多个Characteristic，一个Characteristic包含一个Value和多个Descriptor，一个Descriptor包含一个Value。

废话不多说，最最关键的部分来了（PS：网上找的  个人没有写过  加深下印象吧）
import android.app.Service;
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.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;

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

/**
* Service for managing connection and data communication with a GATT server
* hosted on a given Bluetooth LE device.
*/
@SuppressLint("NewApi")
public class BLEService extends Service {
private final static String TAG = BLEService.class.getSimpleName();

private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private String mBluetoothDeviceAddress;
private BluetoothGatt mBluetoothGatt;
private int mConnectionState = STATE_DISCONNECTED;

private static final int STATE_DISCONNECTED = 0;
private static final int STATE_CONNECTING = 1;
private static final int STATE_CONNECTED = 2;

public final static String ACTION_GATT_CONNECTED =
"com.example.bledemo.ACTION_GATT_CONNECTED";
public final static String ACTION_GATT_DISCONNECTED =
"com.example.bledemo.ACTION_GATT_DISCONNECTED";
public final static String ACTION_GATT_SERVICES_DISCOVERED =
"com.example.bledemo.ACTION_GATT_SERVICES_DISCOVERED";
public final static String ACTION_DATA_AVAILABLE =
"com.example.bledemo.ACTION_DATA_AVAILABLE";
public final static String EXTRA_DATA =
"com.example.bledemo.EXTRA_DATA";

public final static UUID UUID_HEART_RATE_MEASUREMENT = UUID
.fromString(SampleGattAttributes.HEART_RATE_MEASUREMENT);

// Implements callback methods for GATT events that the app cares about. For
// example,
// connection change and services discovered.
//	实现了GATT事件的回调方法,应用关心。例如,连接变化和服务发现
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status,
int newState) {
String intentAction;
System.out.println("=======status:" + status);
if (newState == BluetoothProfile.STATE_CONNECTED) {
intentAction = ACTION_GATT_CONNECTED;
mConnectionState = STATE_CONNECTED;
broadcastUpdate(intentAction);
Log.i(TAG, "Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:"
+ mBluetoothGatt.discoverServices());

} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
intentAction = ACTION_GATT_DISCONNECTED;
mConnectionState = STATE_DISCONNECTED;
Log.i(TAG, "Disconnected from GATT server.");
broadcastUpdate(intentAction);
}
}

@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}

@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic, int status) {
System.out.println("onCharacteristicRead");
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
}

@Override
public void onDescriptorWrite(BluetoothGatt gatt,
BluetoothGattDescriptor descriptor, int status) {

System.out.println("onDescriptorWriteonDescriptorWrite = " + status
+ ", descriptor =" + descriptor.getUuid().toString());
}

@Override
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
if (characteristic.getValue() != null) {

System.out.println(characteristic.getStringValue(0));
}
System.out.println("--------onCharacteristicChanged-----");
}

@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
System.out.println("rssi = " + rssi);
}

public void onCharacteristicWrite(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic, int status) {
System.out.println("--------write success----- status:" + status);

};
};

private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}

private void broadcastUpdate(final String action,
final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);

// This is special handling for the Heart Rate Measurement profile. Data
// parsing is
// carried out as per profile specifications:
// http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
int flag = characteristic.getProperties();
int format = -1;
if ((flag & 0x01) != 0) {
format = BluetoothGattCharacteristic.FORMAT_UINT16;
Log.d(TAG, "Heart rate format UINT16.");
} else {
format = BluetoothGattCharacteristic.FORMAT_UINT8;
Log.d(TAG, "Heart rate format UINT8.");
}
final int heartRate = characteristic.getIntValue(format, 1);
System.out.println("Received heart rate: %d" + heartRate);
Log.d(TAG, String.format("Received heart rate: %d", heartRate));
intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
} else {
// For all other profiles, writes the data formatted in HEX.
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(
data.length);
for (byte byteChar : data)
stringBuilder.append(String.format("%02X ", byteChar));

System.out.println("ppp" + new String(data) + "\n"
+ stringBuilder.toString());
intent.putExtra(EXTRA_DATA, new String(data) + "\n"
+ stringBuilder.toString());
}
}
sendBroadcast(intent);
}

public class LocalBinder extends Binder {
BLEService getService() {
return BLEService.this;
}
}

@Override
public IBinder onBind(Intent intent) {
return mBinder;
}

@Override
public boolean onUnbind(Intent intent) {
// After using a given device, you should make sure that
// BluetoothGatt.close() is called
// such that resources are cleaned up properly. In this particular
// example, close() is
// invoked when the UI is disconnected from the Service.
close();
return super.onUnbind(intent);
}

private final IBinder mBinder = new LocalBinder();

/**
* Initializes a reference to the local Bluetooth adapter.
*
* @return Return true if the initialization is successful.
*/
public boolean initialize() {
// For API level 18 and above, get a reference to BluetoothAdapter
// through
// BluetoothManager.
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
Log.e(TAG, "Unable to initialize BluetoothManager.");
return false;
}
}

mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
return false;
}

return true;
}

/**
* Connects to the GATT server hosted on the Bluetooth LE device.
*
* @param address
*            The device address of the destination device.
*
* @return Return true if the connection is initiated successfully. The
*         connection result is reported asynchronously through the
*         {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
*         callback.
*/
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG,
"BluetoothAdapter not initialized or unspecified address.");
return false;
}

// Previously connected device. Try to reconnect. (先前连接的设备。 尝试重新连接)
if (mBluetoothDeviceAddress != null
&& address.equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
Log.d(TAG,
"Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}

final BluetoothDevice device = mBluetoothAdapter
.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "Device not found.  Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the
// autoConnect
// parameter to false.
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
Log.d(TAG, "Trying to create a new connection.");
mBluetoothDeviceAddress = address;
mConnectionState = STATE_CONNECTING;
return true;
}

/**
* Disconnects an existing connection or cancel a pending connection. The
* disconnection result is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.disconnect();
}

/**
* After using a given BLE device, the app must call this method to ensure
* resources are released properly.
*/
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
}

public void wirteCharacteristic(BluetoothGattCharacteristic characteristic) {

if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}

mBluetoothGatt.writeCharacteristic(characteristic);

}

/**
* Request a read on a given {@code BluetoothGattCharacteristic}. The read
* result is reported asynchronously through the
* {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*
* @param characteristic
*            The characteristic to read from.
*/
public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.readCharacteristic(characteristic);
}

/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic
*            Characteristic to act on.
* @param enabled
*            If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(
BluetoothGattCharacteristic characteristic, boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID
.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
if (descriptor != null) {
System.out.println("write descriptor");
descriptor
.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mBluetoothGatt.writeDescriptor(descriptor);
}
/*
* // This is specific to Heart Rate Measurement. if
* (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
* System
* .out.println("characteristic.getUuid() == "+characteristic.getUuid
* ()+", "); BluetoothGattDescriptor descriptor =
* characteristic.getDescriptor
* (UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
* descriptor
* .setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
* mBluetoothGatt.writeDescriptor(descriptor); }
*/
}

/**
* Retrieves a list of supported GATT services on the connected device. This
* should be invoked only after {@code BluetoothGatt#discoverServices()}
* completes successfully.
*
* @return A {@code List} of supported services.
*/
public List<BluetoothGattService> getSupportedGattServices() {
if (mBluetoothGatt == null)
return null;

return mBluetoothGatt.getServices();
}

/**
* Read the RSSI for a connected remote device.
* */
public boolean getRssiVal() {
if (mBluetoothGatt == null)
return false;

return mBluetoothGatt.readRemoteRssi();
}
}

import java.util.HashMap;

/**
* This class includes a small subset of standard GATT attributes for demonstration purposes.
* 这个类包括一小部分标准GATT属性用于演示目的
*/
public class SampleGattAttributes {
private static HashMap<String, String> attributes = new HashMap();
public static String HEART_RATE_MEASUREMENT = "0000C004-0000-1000-8000-00805f9b34fb";
public static String CLIENT_CHARACTERISTIC_CONFIG = "00002902-0000-1000-8000-00805f9b34fb";

static {
// Sample Services.
attributes.put("0000fff00000-1000-8000-00805f9b34fb", "Heart Rate Service");
attributes.put("0000180a-0000-1000-8000-00805f9b34fb", "Device Information Service");
// Sample Characteristics.
attributes.put(HEART_RATE_MEASUREMENT, "Heart Rate Measurement");
attributes.put("00002a29-0000-1000-8000-00805f9b34fb", "Manufacturer Name String");
}

public static String lookup(String uuid, String defaultName) {
String name = attributes.get(uuid);
return name == null ? defaultName : name;
}
}