接着上篇藍牙通信往下寫,若有不對還請指出,大家共同進步。
先大概瞭解藍牙掃描連接收發數據的工作流程,這裏只提notify接收數據,read自動忽略。首先藍牙需要動態權限,個人採用動態權限的開源庫permissionsdispatcher,不懂若有需要可以github檢索這裏不在敘述(本篇多爲代碼塊,完整接口和類可以自己拷貝到項目+開源庫就可以直接用)
首先是一個接口定義,關於藍牙的使用之前的一些判斷OnBluetoothInspectListener
public interface IBluetoothInspectListener {
public interface OnBluetoothCheckListener {
void onOpenBluetoothState();
void onRefuseOpenBluetoothState();
void unSupportBluetooth();
}
public interface OnBluetoothInspectListener {
void onInspect();
void onSupportBluetooth();
boolean isOpenBluetooth();
void onOpenBluetooth();
}
}
實現類OnBluetoothInspectListenerImpl
public class OnBluetoothInspectListenerImpl implements OnBluetoothInspectListener {
private static final int REQUEST_ENABLE_BT = 1;
private static OnBluetoothInspectListenerImpl instance;
private OnBluetoothCheckListener onBluetoothCheckListener;
BluetoothAdapter mBluetoothAdapter;
Activity mContext;
private OnBluetoothInspectListenerImpl(Activity mContext, OnBluetoothCheckListener onBluetoothCheckListener) {
this.mContext = mContext;
this.onBluetoothCheckListener = onBluetoothCheckListener;
this.mBluetoothAdapter = ((BluetoothManager)mContext.getSystemService("bluetooth")).getAdapter();
}
public static OnBluetoothInspectListenerImpl init(Activity activity, OnBluetoothCheckListener onBluetoothCheckListener) {
instance = new OnBluetoothInspectListenerImpl(activity, onBluetoothCheckListener);
return instance;
}
public void onInspect() {
if(this.mBluetoothAdapter == null) {
this.onBluetoothCheckListener.unSupportBluetooth();
} else {
this.onSupportBluetooth();
}
}
public void onSupportBluetooth() {
if(this.isOpenBluetooth()) {
this.onBluetoothCheckListener.onOpenBluetoothState();
} else {
this.onOpenBluetooth();
}
}
public boolean isOpenBluetooth() {
return this.mBluetoothAdapter.isEnabled();
}
public void onOpenBluetooth() {
Intent enableBtIntent = new Intent("android.bluetooth.adapter.action.REQUEST_ENABLE");
this.mContext.startActivityForResult(enableBtIntent, 1);
}
public void performResult(int requestCode, int resultCode) {
switch(requestCode) {
case 1:
if(this.onBluetoothCheckListener != null) {
if(this.isOpenBluetooth()) {
this.onBluetoothCheckListener.onOpenBluetoothState();
} else {
this.onBluetoothCheckListener.onRefuseOpenBluetoothState();
}
}
default:
}
}
public BluetoothAdapter getBluetoothAdapter() {
return this.mBluetoothAdapter;
}
}
具體使用這塊的代碼塊(根據動態權限結果,有藍牙的權限後調用onBluetoothInspectListenerImpl.onInspect();方法即可,會自動根據相應函數執行回調,onOpenBluetoothState方法回調時表示可以開始藍牙掃描了)
public class BluetoothActivity extends AppCompatActivity implements IBluetoothInspectListener.OnBluetoothCheckListener{
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//.........略..................
onBluetoothInspectListenerImpl = OnBluetoothInspectListenerImpl.init(this, this);
//.......動態權限.........
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
onBluetoothInspectListenerImpl.performResult(requestCode, resultCode);
}
@Override
public void onOpenBluetoothState() {
//掃描讀寫
startScan();
}
@Override
public void onRefuseOpenBluetoothState() {
showInformation("您拒絕了開啓藍牙將影響到功能的使用");
finish();
}
@Override
public void unSupportBluetooth() {
showInformation("手機不支持低功耗藍牙通信");
finish();
}
}
藍牙掃描代碼個人感覺比較繁瑣,最後選用了小米一哥們的開源庫https://github.com/dingjikerbo/BluetoothKit,由於該庫沒有提供compile路徑,之前blog提到過搭建maven私服,於是下載源碼下來把module上傳到了本地maven私服,根據開發需求,進行了簡單得的封裝
接口定義IBluetoothListener、BluetoothCallback
public interface IBluetoothListener {
public void startScan();
public void stopScan();
public void connect();
public void read();
public void write();
public void registerNotify();
public void unRegisterNotify();
public void disconnect();
public void release();
}
public interface BluetoothCallback {
public void showInformation(String information);
public void toastMessage(String message);
public void readResponse(byte[] bytes);
}
實現類OnBluetootListener ,UUID特別重要,不能隨便copy,最好找硬件那邊要。(如果你拷貝了該類需要自行補充完整UUID)
public class OnBluetootListener implements IBluetoothListener {
public static final UUID SERVICE_UUID ;
public static final UUID WRITE_CHARA ;
public static final UUID READ_CHARA ;
private byte[] bytes;
private String deviceMac;
private SearchRequest request;
private IBluetoothClient mClient;
private BluetoothDevice currentBluetoothDevice;
private BluetoothCallback callback;
private boolean isStopScan = false;
public OnBluetootListener(Context context, String deviceMac, byte[] bytes, BluetoothCallback callback) {
this.deviceMac = deviceMac;
this.bytes = bytes;
this.callback = callback;
mClient = BluetoothClient.getInstance(context);
request = new SearchRequest.Builder()
.searchBluetoothLeDevice(3000, 1) // scan Bluetooth LE device for 3000ms, 3 times
.searchBluetoothClassicDevice(5000) // then scan Bluetooth Classic device for 5000ms, 1 time
.searchBluetoothLeDevice(2000) // at last scan Bluetooth LE device for 2000ms
.build();
}
@Override
public void startScan() {
//執行掃描任務
callback.showInformation("掃描設備..");
mClient.search(request, new SearchResponse() {
@Override
public void onSearchStarted() {
}
@Override
public void onDeviceFounded(SearchResult device) {
if (device.device.getAddress().equals(deviceMac)&&!isStopScan) {
isStopScan=true;
//掃描到指定設備後停止掃描
callback.showInformation("發現設備");
currentBluetoothDevice = device.device;
//連接設備
connect();
stopScan();
}
}
@Override
public void onSearchStopped() {
if (currentBluetoothDevice == null) {
callback.toastMessage("沒有發現匹配的設備");
}
}
@Override
public void onSearchCanceled() {
}
});
}
@Override
public void stopScan() {
mClient.stopSearch();
}
@Override
public void connect() {
mClient.connect(deviceMac, new BleConnectResponse() {
@Override
public void onResponse(int code, Bundle data) {
if (code == REQUEST_SUCCESS) {
//連接成功
//註冊notify以後發送數據和讀取數據
callback.showInformation("連接成功");
registerNotify();
} else {
release();
callback.toastMessage("連接失敗");
}
}
});
}
@Override
public void read() {
mClient.read(deviceMac, SERVICE_UUID, READ_CHARA, new BleReadResponse() {
@Override
public void onResponse(int code, byte[] data) {
if (code == REQUEST_SUCCESS) {
callback.showInformation(data.toString());
} else {
release();
callback.toastMessage("讀取數據失敗");
}
}
});
}
@Override
public void write() {
mClient.write(deviceMac, SERVICE_UUID, WRITE_CHARA, bytes, new BleWriteResponse() {
@Override
public void onResponse(int code) {
if (code == REQUEST_SUCCESS) {
callback.showInformation("發送數據成功");
// read();
} else {
release();
callback.toastMessage("發送數據失敗");
}
}
});
}
public void write(byte[] bytes) {
mClient.write(deviceMac, SERVICE_UUID, WRITE_CHARA, bytes, new BleWriteResponse() {
@Override
public void onResponse(int code) {
if (code == REQUEST_SUCCESS) {
} else {
release();
callback.toastMessage("發送數據失敗");
}
}
});
}
@Override
public void registerNotify() {
mClient.notify(deviceMac, SERVICE_UUID, READ_CHARA, new BleNotifyResponse() {
@Override
public void onNotify(UUID service, UUID character, byte[] value) {
callback.readResponse(value);
}
@Override
public void onResponse(int code) {
if (code == REQUEST_SUCCESS) {
// callback.showInformation("註冊藍牙通知成功");
//write數據需要注意,個別手機有限制一次發送數據最大值,如果超過了需要自己分多次發送
callback.showInformation("數據已發送,等待數據響應");
} else {
release();
callback.toastMessage("發送失敗,請再試一次");
}
}
});
}
@Override
public void unRegisterNotify() {
mClient.unnotify(deviceMac, SERVICE_UUID, READ_CHARA, new BleUnnotifyResponse() {
@Override
public void onResponse(int code) {
}
});
}
@Override
public void disconnect() {
mClient.disconnect(deviceMac);
}
@Override
public void release() {
unRegisterNotify();
disconnect();
stopScan();
}
public BluetoothDevice getCurrentBluetoothDevice(){
return currentBluetoothDevice;
}
}
根據上面的實現類,使用時只需在onCreate獲取實現類實例,在藍牙判斷檢查的回掉函數執行掃描,通過這個實現類代理即可
listener = new OnBluetootListener(this,macAddress,sendMessageBytes,this);
//...........................................
@Override
public void onOpenBluetoothState() {
//掃描讀寫
listener.startScan();
}
開啓掃描,掃描到指定設備,開始註冊藍牙通知服務,註冊成功了就開始寫入數據等待返回數據,大致工作流程就這樣的,主要關注回掉函數如下
@Override
public void showInformation(String message) {
toast.setText(message);
// Logger.e(message);
}
@Override
public void toastMessage(String s) {
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_SHORT).show();
handler.postDelayed(new Runnable() {
@Override
public void run() {
finish();
}
},1000);
}
@Override
public void readResponse(byte[] bytes) {
}
再提一點,數據按照字節傳輸,一次接受的字節長度有限制,如果要保證自己接受完整,需要自己採用相應的辦法,如下
@Override
public void readResponse(byte[] bytes) {
saveBytes(bytes, responseBytes);
if (readCount == responseBytes.length) {
onResponseReadResult(responseBytes);//解析回傳數據
}
}
/**
* 拼接byte數據
*
* @param src
* @param ds
*/
public void saveBytes(byte[] src, byte[] ds) {
for (int i = 0; i < src.length; i++) {
ds[i + readCount] = src[i];
}
readCount = readCount + src.length;
}
最後一點,與硬件通信一般都會用到Crc8、Crc16算法相關的,而硬件開發用C與java有所不同,算法轉換這裏提供一個Crc8的一個類(網上多爲c char,java的有長度限制直接拷貝到java裏用會有點問題)
public class Crc8Helper {
/**
* CRC8算法
*
* @param bytes
* @return
*/
public static byte CRC8_Table(byte[] bytes)// counter默認爲2
{
return calcCrc8(bytes);
}
static byte[] crc8_tab = {(byte) 0, (byte) 94, (byte) 188, (byte) 226, (byte) 97, (byte) 63, (byte) 221, (byte) 131, (byte) 194, (byte) 156, (byte) 126, (byte) 32, (byte) 163, (byte) 253, (byte) 31, (byte) 65, (byte) 157, (byte) 195, (byte) 33, (byte) 127, (byte) 252, (byte) 162, (byte) 64, (byte) 30, (byte) 95, (byte) 1, (byte) 227, (byte) 189, (byte) 62, (byte) 96, (byte) 130, (byte) 220, (byte) 35, (byte) 125, (byte) 159, (byte) 193, (byte) 66, (byte) 28, (byte) 254, (byte) 160, (byte) 225, (byte) 191, (byte) 93, (byte) 3, (byte) 128, (byte) 222, (byte) 60, (byte) 98, (byte) 190, (byte) 224, (byte) 2, (byte) 92, (byte) 223, (byte) 129, (byte) 99, (byte) 61, (byte) 124, (byte) 34, (byte) 192, (byte) 158, (byte) 29, (byte) 67, (byte) 161, (byte) 255, (byte) 70, (byte) 24,
(byte) 250, (byte) 164, (byte) 39, (byte) 121, (byte) 155, (byte) 197, (byte) 132, (byte) 218, (byte) 56, (byte) 102, (byte) 229, (byte) 187, (byte) 89, (byte) 7, (byte) 219, (byte) 133, (byte) 103, (byte) 57, (byte) 186, (byte) 228, (byte) 6, (byte) 88, (byte) 25, (byte) 71, (byte) 165, (byte) 251, (byte) 120, (byte) 38, (byte) 196, (byte) 154, (byte) 101, (byte) 59, (byte) 217, (byte) 135, (byte) 4, (byte) 90, (byte) 184, (byte) 230, (byte) 167, (byte) 249, (byte) 27, (byte) 69, (byte) 198, (byte) 152, (byte) 122, (byte) 36, (byte) 248, (byte) 166, (byte) 68, (byte) 26, (byte) 153, (byte) 199, (byte) 37, (byte) 123, (byte) 58, (byte) 100, (byte) 134, (byte) 216, (byte) 91, (byte) 5, (byte) 231, (byte) 185, (byte) 140, (byte) 210, (byte) 48, (byte) 110, (byte) 237,
(byte) 179, (byte) 81, (byte) 15, (byte) 78, (byte) 16, (byte) 242, (byte) 172, (byte) 47, (byte) 113, (byte) 147, (byte) 205, (byte) 17, (byte) 79, (byte) 173, (byte) 243, (byte) 112, (byte) 46, (byte) 204, (byte) 146, (byte) 211, (byte) 141, (byte) 111, (byte) 49, (byte) 178, (byte) 236, (byte) 14, (byte) 80, (byte) 175, (byte) 241, (byte) 19, (byte) 77, (byte) 206, (byte) 144, (byte) 114, (byte) 44, (byte) 109, (byte) 51, (byte) 209, (byte) 143, (byte) 12, (byte) 82, (byte) 176, (byte) 238, (byte) 50, (byte) 108, (byte) 142, (byte) 208, (byte) 83, (byte) 13, (byte) 239, (byte) 177, (byte) 240, (byte) 174, (byte) 76, (byte) 18, (byte) 145, (byte) 207, (byte) 45, (byte) 115, (byte) 202, (byte) 148, (byte) 118, (byte) 40, (byte) 171, (byte) 245, (byte) 23, (byte) 73, (byte) 8,
(byte) 86, (byte) 180, (byte) 234, (byte) 105, (byte) 55, (byte) 213, (byte) 139, (byte) 87, (byte) 9, (byte) 235, (byte) 181, (byte) 54, (byte) 104, (byte) 138, (byte) 212, (byte) 149, (byte) 203, (byte) 41, (byte) 119, (byte) 244, (byte) 170, (byte) 72, (byte) 22, (byte) 233, (byte) 183, (byte) 85, (byte) 11, (byte) 136, (byte) 214, (byte) 52, (byte) 106, (byte) 43, (byte) 117, (byte) 151, (byte) 201, (byte) 74, (byte) 20, (byte) 246, (byte) 168, (byte) 116, (byte) 42, (byte) 200, (byte) 150, (byte) 21, (byte) 75, (byte) 169, (byte) 247, (byte) 182, (byte) 232, (byte) 10, (byte) 84, (byte) 215, (byte) 137, (byte) 107, 53};
/**
* 計算數組的CRC8校驗值
*
* @param data 需要計算的數組
* @return CRC8校驗值
*/
public static byte calcCrc8(byte[] data) {
return calcCrc8(data, 0, data.length, (byte) 0);
}
/**
* 計算CRC8校驗值
*
* @param data 數據
* @param offset 起始位置
* @param len 長度
* @return 校驗值
*/
public static byte calcCrc8(byte[] data, int offset, int len) {
return calcCrc8(data, offset, len, (byte) 0);
}
/**
* 計算CRC8校驗值
*
* @param data 數據
* @param offset 起始位置
* @param len 長度
* @param preval 之前的校驗值
* @return 校驗值
*/
public static byte calcCrc8(byte[] data, int offset, int len, byte preval) {
byte ret = preval;
for (int i = offset; i < (offset + len); ++i) {
ret = crc8_tab[(0x00ff & (ret ^ data[i]))];
}
return ret;
}
/**
* 計算CRC8校驗值
*
* @param data
* 數據
* @param offset
* 起始位置
* @param len
* 長度
* @param preval
* 之前的校驗值
* @return 校驗值
*/
public static byte parseCalcCrc8(byte[] data, int offset, int len, byte preval) {
byte ret = preval;
for (int i = offset; i < (offset + len); ++i) {
ret = crc8_tab[(0x00ff & (ret ^ data[i]))];
}
return ret;
}
}
小結:藍牙通信這塊的開發會遇到高地位的轉換、機型適配的煩惱(小米5.1、4.4手機),個人這塊工作暫時告一段落,用過api直接寫通信模塊,也用過第三方框架,感覺都是麻煩事,還要動態權限一對代碼,希望有一天有位大神閃亮登場,搞個比較牛逼的開源庫讓我一鍵調用就好了。