安卓BLE蓝牙通讯

蓝牙测试demo
简介
  Android手机间通过蓝牙方式进行通信，有两种常见的方式，一种是socket方式（传统蓝牙），另一种是通过GATT（BLE蓝牙）。与传统蓝牙相比，BLE 旨在大幅降低功耗。这样一来，应用就可以与功率要求更严格的 BLE 设备（如近程传感器、心率监测器和健身设备）进行通信。

实现
1.权限
  如需使用BLE蓝牙 API，需要在AndroidManifest.xml清单文件中声明多项权限，并动态获取相应权限。一旦应用获得使用蓝牙的权限，应用就需要访问 BluetoothAdapter 并确定设备是否支持蓝牙。如果蓝牙可用，设备将扫描附近的 BLE 设备。发现设备后，系统会连接到 BLE 设备上的 GATT 服务器来发现 BLE 设备的功能。建立连接后，可以根据可用的服务和特征通过已连接的设备传输数据。
  在高版本的安卓设备中，除蓝牙基本权限外，还需用到位置权限，否则会扫描不到蓝牙。
  AndroidManifest.xml文件如下：

    <uses-permission android:name="android.permission.BLUETOOTH" /><uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /><uses-permission android:name="android.permission.BLUETOOTH_CONNECT" /><uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /><uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /><uses-permission android:name="android.permission.BLUETOOTH_SCAN" /><uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />

动态权限申请如下，可放在MainActivity中。

    // todo 动态申请权限private void initPermission() {List<String> mPermissionList = new ArrayList<>();if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {// Android 版本大于等于 Android12 时mPermissionList.add(android.Manifest.permission.BLUETOOTH_SCAN);mPermissionList.add(android.Manifest.permission.BLUETOOTH_ADVERTISE);mPermissionList.add(android.Manifest.permission.BLUETOOTH_CONNECT);}mPermissionList.add(android.Manifest.permission.ACCESS_COARSE_LOCATION);mPermissionList.add(android.Manifest.permission.ACCESS_FINE_LOCATION);if (mPermissionList.size() > 0) {ActivityCompat.requestPermissions(this, mPermissionList.toArray(new String[0]), 1001);}}

2.扫描蓝牙设备

    //默认扫描BLE蓝牙时长10s 可更改private final Long mScanTime = 10 * 1000L;private final List<ScanFilter> mScanFilterList = new ArrayList<>();private final ScanSettings mScanSettings = new ScanSettings.Builder().build();/*** 蓝牙扫描*/@SuppressLint("MissingPermission")public void startScanBle() {if (!getBleEnable()) {
//            openBlueTooth();TimerUtil.cancelTimer();ToastUtil.showToast("蓝牙未打开", 2000);return;}if (!GpsAdmin.getInstance().isGpsOn()) {TimerUtil.cancelTimer();ToastUtil.showToast("定位未打开", 2000);return;}Log.i(TAG, "开始扫描蓝牙");mBleCurrentInfo.clearBleResult();BleCallback.instance.startLeScan(mBluetoothAdapter, new ScanCallback() {@Overridepublic void onScanResult(int callbackType, ScanResult result) {super.onScanResult(callbackType, result);try {if (result.getDevice() == null || result.getDevice().getAddress() == null) {return;}if (result.getDevice().getName() == null || Objects.equals(result.getDevice().getName(), "")) {return;}for (BleDeviceBean bean : mBleCurrentInfo.getBleList()) {if (Objects.equals(bean.getBleAddress(), result.getDevice().getAddress())) {return;}}Log.i(TAG, "NAME:" + result.getDevice().getName() + ",ADDRESS:" + result.getDevice().getAddress());BleDeviceBean bean = new BleDeviceBean(result.getDevice().getName(), result.getDevice().getAddress(), false);mBleCurrentInfo.addBleResult(bean);} catch (Exception e) {Log.i(TAG, e.toString());}}@Overridepublic void onBatchScanResults(List<ScanResult> results) {super.onBatchScanResults(results);}@Overridepublic void onScanFailed(int errorCode) {super.onScanFailed(errorCode);}}, mScanTime, mScanFilterList, mScanSettings);}

  BleCallback中startLeScan()方法如下。

    /*** 开启ble扫描*/@RequiresPermission(android.Manifest.permission.BLUETOOTH_SCAN)public void startLeScan(BluetoothAdapter bluetoothAdapter,ScanCallback scanCallback,Long scanTime,List<ScanFilter> filters,ScanSettings scanSettings) {try {if (bluetoothAdapter == null) {return;}if (scanCallback == null) {return;}BluetoothLeScanner bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();if (bluetoothLeScanner == null) {return;}if (mScanCallback != null && bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {bluetoothLeScanner.stopScan(mScanCallback);mScanCallback = null;}TimerUtil.cancelDialogTimer();mScanCallback = scanCallback;bluetoothLeScanner.startScan(filters,scanSettings,mScanCallback);TimerUtil.startDialogTask(new TimerTask() {@RequiresPermission(android.Manifest.permission.BLUETOOTH_SCAN)@Overridepublic void run() {if (mScanCallback != null && bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {bluetoothLeScanner.stopScan(mScanCallback);mScanCallback = null;}}}, scanTime);} catch (Exception e) {Log.i(TAG, "蓝牙扫描异常");}}

3.连接GATT服务器

    public void connect(Boolean isAutoConnect,BluetoothDevice bluetoothDevice) {bluetoothDevice.connectGatt(Utils.getApp(), isAutoConnect, this, BluetoothDevice.TRANSPORT_LE);}

  在设备连接蓝牙后会触发onConnectionStateChange回调。

public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {Log.i(TAG, "onConnectionStateChange,status:" + status +",newState:" + newState);switch (newState) {case BluetoothProfile.STATE_CONNECTED:BleDevice bleDevice = new BleDevice();bleDevice.setDeviceName(gatt.getDevice().getName());bleDevice.setMacAddress(gatt.getDevice().getAddress());bleDevice.setGatt(gatt);mConnectedBleDeviceList.add(bleDevice);Log.i(TAG, gatt.getDevice().getAddress() + "已连接");if (mConnectListener != null) {mConnectListener.onConnectSuccess(gatt);}try {Thread.sleep(50);} catch (InterruptedException e) {Log.i(TAG, e.toString());}gatt.discoverServices();break;case BluetoothProfile.STATE_DISCONNECTED:Iterator<BleDevice> iterator = mConnectedBleDeviceList.iterator();while (iterator.hasNext()) {BleDevice next = iterator.next();if (Objects.equals(next.getMacAddress(), gatt.getDevice().getAddress())) {iterator.remove();}}Log.i(TAG, gatt.getDevice().getAddress() + "断开连接");if (mConnectListener != null) {mConnectListener.onDisconnect(gatt);}gatt.close();break;default:break;}}

  当newState值为BluetoothProfile.STATE_CONNECTED表示连接外围设备成功，其中gatt.discoverServices()方法尤为关键，如果不调用此方法，就无法触发onServicesDiscovered()回调，就无法发现所连接蓝牙设备的服务UUID；除此之外，如果连接上后立刻调用此方法，会有可能无法触发onServicesDiscovered()方法。

4.绑定UUID
  在设备触发onServicesDiscovered回调时，获取到蓝牙所有服务。

    public void onServicesDiscovered(BluetoothGatt gatt, int status) {Log.i(TAG, "onServicesDiscovered,status:" + status);switch (status) {case BluetoothGatt.GATT_SUCCESS:if (!mConnectedBleDeviceList.isEmpty()) {mConnectedBleDeviceList.get(mConnectedBleDeviceList.size() - 1).setServiceList(gatt.getServices());if (mConnectListener != null) {mConnectListener.onServicesDiscovered(gatt, gatt.getServices());}}break;default:if (mConnectListener != null) {mConnectListener.onServicesDiscoverFailed(status);}break;}}

  正常情况下，当触发触发onConnectSuccess回调时，设备已经连上的蓝牙的GATT，此时可认为蓝牙已连接，此时中心设备是无法和外围设备通讯的，还需根据蓝牙协议绑定指定的特征UUID，一般中心设备接收数据的为NOTIFY_CHARACTERISTIC_UUID，向外围设备发送消息的为WRITE_CHARACTERISTIC_UUID，大部分外设备还有描述符，例如接收数据需要的描述符NOTIFY_DESCRIPTOR_UUID等。下面是我的蓝牙设备使用到的UUID。

public class UsedUUID {public static UUID SERVICE_UUID = UUID.fromString("0783b03e-8535-b5a0-7140-a304d2495cb7");public static UUID WRITE_CHARACTERISTIC_UUID = UUID.fromString("0783b03e-8535-b5a0-7140-a304d2495cba");public static UUID NOTIFY_CHARACTERISTIC_UUID = UUID.fromString("0783b03e-8535-b5a0-7140-a304d2495cb8");public static UUID NOTIFY_DESCRIPTOR_UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");
}

  获取到所有服务后，根据蓝牙协议，绑定指定的特征UUID。此demo中实际以设备找到蓝牙服务指定UUID，并绑定成功视为真正连接成功。

public void onServicesDiscovered(BluetoothGatt gatt, List<BluetoothGattService> services) {Log.i(TAG, "发现服务UUID");boolean isNext = false;for (BluetoothGattService service: services) {if (service.getUuid().toString().equals(UsedUUID.SERVICE_UUID.toString())) {Log.i(TAG, "找到SERVICE_UUID");mOperateService = service;mBleGattCharacteristics.clear();mBleGattCharacteristics.addAll(service.getCharacteristics());isNext = true;break;}}if (!isNext) {Log.i(TAG, "未找到指定的服务UUID");disConnectGatt(false);return;}isNext = false;List<BluetoothGattCharacteristic> bleGattCharacteristics = new ArrayList<>(mBleGattCharacteristics);for (BluetoothGattCharacteristic bluetoothGattCharacteristic: bleGattCharacteristics) {if (bluetoothGattCharacteristic.getUuid().toString().equals(UsedUUID.NOTIFY_CHARACTERISTIC_UUID.toString())) {Log.i(TAG, "找到NOTIFY_CHARACTERISTIC_UUID");mNotifyCharacteristic = bluetoothGattCharacteristic;isNext = true;}if (bluetoothGattCharacteristic.getUuid().toString().equals(UsedUUID.WRITE_CHARACTERISTIC_UUID.toString())) {Log.i(TAG, "找到WRITE_CHARACTERISTIC_UUID");mWriteCharacteristic = bluetoothGattCharacteristic;}}if (isNext) {try {Log.i(TAG, "BLE蓝牙连接成功");if (mBleCurrentInfo.isConnect()) {mBleCurrentInfo.setConnect(false);mOperateGatt.close();}for (BleDeviceBean bean: mBleCurrentInfo.getBleList()) {bean.setBleConnect(false);}mOperateGatt = gatt;subscribeNotify();Log.i(TAG, "BLE蓝牙绑定成功");mBleCurrentInfo.setConnect(true);if (mIsFirstConnect) {mBleCurrentInfo.getBleList().get(0).setBleConnect(true);}
//                if (Objects.equals(mBleCurrentInfo.getBleAddress(), gatt.getDevice().getAddress()) && !mBleCurrentInfo.getBleList().isEmpty()) {
//                    mBleCurrentInfo.getBleList().get(0).setBleConnect(true);
//                }mBleCurrentInfo.setConnect(true);mBleCurrentInfo.setBleName(gatt.getDevice().getName());mBleCurrentInfo.setBleAddress(gatt.getDevice().getAddress());mBleCurrentInfo.updateScanBean();if (mDiscoveredListener != null) {mDiscoveredListener.onServicesDiscovered(gatt);}if (mBleListener != null) {mBleListener.onConnectSuccess(true);}} catch (Exception e) {Log.i(TAG, "BLE蓝牙连接异常");disConnectGatt(false);}} else {disConnectGatt(false);}}

5.接收消息
  所有接收的消息都是触发连接蓝牙时传入的BluetoothGattCallback回调中onCharacteristicChanged方法，外围设备会将数据的变更写入属性为NOTIFY的BluetoothGattCharacteristic中，每当BluetoothGattCharacteristic的值发生变化时，中心设备都会收到通知。

    public void onCharacteristicChanged(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic) {if (mNotifyListener != null) {mNotifyListener.onCharacteristicChange(gatt, characteristic);}}

6.发送消息
  发送消息时，我们中心设备只需改变属性为WRITED的BluetoothGattCharacteristic值，外围设备就可以收到我们发送的消息。

    public void sendMessage(byte[] message) {if (!mBleCurrentInfo.isConnect()) {ToastUtil.showToast("蓝牙未连接，请连接蓝牙!", 2000);return;}if (mOperateGatt == null || mWriteCharacteristic == null) {Log.i(TAG, "发送消息失败,未持有相关服务");return;}mWriteCharacteristic.setValue(message);mOperateGatt.writeCharacteristic(mWriteCharacteristic);}

7.效果演示
在这里插入图片描述

这里以发送HD+RPC=3,{“paramtype”:1}为例子，将String转为byte数组后发送给外围设备，接收外围设备数据为byte数组，未经过转换。
8.核心代码
① BleAdmin完整代码：

package com.example.bluetooth.util;import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanFilter;
import android.bluetooth.le.ScanResult;
import android.bluetooth.le.ScanSettings;
import android.content.Context;
import android.util.Log;import com.example.bluetooth.bean.BleCurrentInfo;
import com.example.bluetooth.bean.BleDeviceBean;
import com.example.bluetooth.callback.BleCallback;
import com.example.bluetooth.intel.BleListener;
import com.example.bluetooth.intel.ConnectListener;
import com.example.bluetooth.intel.DiscoveredListener;
import com.example.bluetooth.intel.NotifyListener;import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.TimerTask;/*** @des: 蓝牙管理类* @date: 2024/9/2* @author: yanghaifeng*/
public class BleAdmin implements ConnectListener, NotifyListener {private final static String TAG = "BleAdmin";private static BleAdmin bleAdmin;private BluetoothAdapter mBluetoothAdapter;private BluetoothGatt mOperateGatt;private BluetoothGattService mOperateService;private BluetoothGattCharacteristic mNotifyCharacteristic;private BluetoothGattCharacteristic mWriteCharacteristic;private int mScanCount = 0; // 扫描次数//默认扫描BLE蓝牙时长10s 可更改private final Long mScanTime = 10 * 1000L;private final List<ScanFilter> mScanFilterList = new ArrayList<>();private final ScanSettings mScanSettings = new ScanSettings.Builder().build();private BleCurrentInfo mBleCurrentInfo = new BleCurrentInfo();  // 已保存的蓝牙设备信息private List<BluetoothGattCharacteristic> mBleGattCharacteristics = new ArrayList<>();private long mStartTime = 0L;private boolean mIsFirstConnect = true;private DiscoveredListener mDiscoveredListener = null;private BleListener mBleListener = null;private Thread mHeartThread = null; // 心跳线程private boolean mIsHeart = false; // 心跳线程运行状态private long mHeartOverTime = 3000L; // 心跳超时时间private long mHeartTime = 0L;private Thread mConnectThread = null; // 重连线程private boolean mIsRunning = false; // 重连线程运行状态long mConnectOverTime = 20 * 1000L; // 重连扫描超时时间public static BleAdmin getInstance() {if (bleAdmin == null) {bleAdmin = new BleAdmin();}return bleAdmin;}public BleAdmin() {BluetoothManager bluetoothManager = (BluetoothManager) Utils.getApp().getSystemService(Context.BLUETOOTH_SERVICE);mBluetoothAdapter = bluetoothManager.getAdapter();BleCallback.instance.setConnectListener(this);BleCallback.instance.setNotifyListener(this);}public BluetoothGatt getOperateGatt() {return mOperateGatt;}public void setOperateGatt(BluetoothGatt mOperateGatt) {this.mOperateGatt = mOperateGatt;}public BluetoothGattService getOperateService() {return mOperateService;}public void setOperateService(BluetoothGattService mOperateService) {this.mOperateService = mOperateService;}public BluetoothGattCharacteristic getNotifyCharacteristic() {return mNotifyCharacteristic;}public void setNotifyCharacteristic(BluetoothGattCharacteristic mNotifyCharacteristic) {this.mNotifyCharacteristic = mNotifyCharacteristic;}public BluetoothGattCharacteristic getWriteCharacteristic() {return mWriteCharacteristic;}public void setWriteCharacteristic(BluetoothGattCharacteristic mWriteCharacteristic) {this.mWriteCharacteristic = mWriteCharacteristic;}public BleCurrentInfo getBleCurrentInfo() {return mBleCurrentInfo;}public void setBleCurrentInfo(BleCurrentInfo mBleCurrentInfo) {this.mBleCurrentInfo = mBleCurrentInfo;}public void setDiscoveredListener(DiscoveredListener mDiscoveredListener) {this.mDiscoveredListener = mDiscoveredListener;}public void setBleListener(BleListener mBleListener) {this.mBleListener = mBleListener;}public long getStartTime() {return mStartTime;}public void setStartTime(long mStartTime) {this.mStartTime = mStartTime;}public void setIsFirstConnect(boolean mIsFirstConnect) {this.mIsFirstConnect = mIsFirstConnect;}/*** 开启心跳线程*/public void startHeartThread() {Log.i(TAG, "开启心跳线程");getHeardThread();mHeartThread.start();}private void getHeardThread() {stopHeartThread();mIsHeart = true;mHeartThread = new Thread(new Runnable() {@Overridepublic void run() {mHeartTime = System.currentTimeMillis();while (mIsHeart) {if (System.currentTimeMillis() - mHeartTime > mHeartOverTime) {Log.i(TAG, "心跳超时");disConnectGatt(true);}}}});}/*** 关闭心跳线程*/public void stopHeartThread() {mIsHeart = false;try {if (mHeartThread != null) {mHeartThread.join();mHeartThread = null;}} catch (InterruptedException i) {Log.i(TAG, i.toString());}}/*** 开启重连线程*/public void startConnectThread() {Log.i(TAG, "开启重连线程");getConnectThread();mConnectThread.start();}private void getConnectThread() {mIsHeart = false;stopConnectThread();mIsRunning = true;mConnectThread = new Thread(new Runnable() {@Overridepublic void run() {startScanBleTask();long time = System.currentTimeMillis();Log.i(TAG, "开始尝试重连");while (mIsRunning && System.currentTimeMillis() - time < mConnectOverTime) {List<BleDeviceBean> beans = new ArrayList<>(mBleCurrentInfo.getBleList());for (BleDeviceBean bean: beans) {try {if (Objects.equals(bean.getBleAddress(), mBleCurrentInfo.getBleAddress())) {Log.i(TAG, "找到重连address:" + mBleCurrentInfo.getBleAddress());int count = 0;Log.i(TAG, "第${count + 1}次尝试连接");connectGatt(getRemoteDevice(bean.getBleAddress()));count++;long currentTime = System.currentTimeMillis();while (count < 3) {if (!mIsRunning) {return;}if (mBleCurrentInfo.isConnect()) {break;}if (System.currentTimeMillis() - currentTime < 5000) {continue;}Log.i(TAG, "第${count + 1}次尝试连接");connectGatt(getRemoteDevice(bean.getBleAddress()));currentTime = System.currentTimeMillis();count++;}mIsRunning = false;break;}} catch (Exception e) {Log.i(TAG, e.toString());}}}}});}/*** 关闭重连线程*/public void stopConnectThread() {mIsRunning = false;try {if (mConnectThread != null) {mConnectThread.join();mConnectThread = null;}} catch (InterruptedException i) {Log.i(TAG, i.toString());} finally {stopScanBle();}}/*** 开启手机蓝牙**/@SuppressLint("MissingPermission")public boolean openBlueTooth() {return mBluetoothAdapter.enable();}/*** 获取蓝牙状态**/public boolean getBleEnable() {return mBluetoothAdapter.isEnabled();}/*** 关闭手机蓝牙**/@SuppressLint("MissingPermission")public void closeBlueTooth() {mBluetoothAdapter.disable();}/*** 获取外围设备广播信息** @param address 外围设备ble地址Mac* @return 通过MAC获取到的外围设备*/public BluetoothDevice getRemoteDevice(String address) {return mBluetoothAdapter.getRemoteDevice(address);}/*** 识别特征功能** @param characteristic service中的特征* @return*/public String detectCharacteristic(BluetoothGattCharacteristic characteristic) {StringBuilder propSb = new StringBuilder();if (characteristic.getProperties() > 0 &&  BluetoothGattCharacteristic.PROPERTY_READ > 0) {propSb.append("Read");}if (characteristic.getProperties() > 0 && BluetoothGattCharacteristic.PROPERTY_WRITE > 0) {if (propSb.length() > 0) {propSb.append("   ");}propSb.append("Write");}if (characteristic.getProperties() > 0 && BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE > 0) {if (propSb.length() > 0) {propSb.append("   ");}propSb.append("Write No Response");}if (characteristic.getProperties() > 0 && BluetoothGattCharacteristic.PROPERTY_NOTIFY > 0) {if (propSb.length() > 0) {propSb.append("   ");}propSb.append("Notify");}if (characteristic.getProperties() > 0 && BluetoothGattCharacteristic.PROPERTY_INDICATE > 0) {if (propSb.length() > 0) {propSb.append("   ");}propSb.append("Indicate");}return propSb.toString();}/*** 蓝牙扫描*/@SuppressLint("MissingPermission")public void startScanBle() {if (!getBleEnable()) {
//            openBlueTooth();TimerUtil.cancelTimer();HandlerUtil.post(()-> ToastUtil.showToast("蓝牙未打开", 2000));return;}if (!GpsAdmin.getInstance().isGpsOn()) {TimerUtil.cancelTimer();HandlerUtil.post(()-> ToastUtil.showToast("定位未打开", 2000));return;}Log.i(TAG, "开始扫描蓝牙");mBleCurrentInfo.clearBleResult();BleCallback.instance.startLeScan(mBluetoothAdapter, new ScanCallback() {@Overridepublic void onScanResult(int callbackType, ScanResult result) {super.onScanResult(callbackType, result);try {if (result.getDevice() == null || result.getDevice().getAddress() == null) {return;}if (result.getDevice().getName() == null || Objects.equals(result.getDevice().getName(), "")) {return;}for (BleDeviceBean bean : mBleCurrentInfo.getBleList()) {if (Objects.equals(bean.getBleAddress(), result.getDevice().getAddress())) {return;}}Log.i(TAG, "NAME:" + result.getDevice().getName() + ",ADDRESS:" + result.getDevice().getAddress());BleDeviceBean bean = new BleDeviceBean(result.getDevice().getName(), result.getDevice().getAddress(), false);mBleCurrentInfo.addBleResult(bean);} catch (Exception e) {Log.i(TAG, e.toString());}}@Overridepublic void onBatchScanResults(List<ScanResult> results) {super.onBatchScanResults(results);}@Overridepublic void onScanFailed(int errorCode) {super.onScanFailed(errorCode);}}, mScanTime, mScanFilterList, mScanSettings);}public void startScanBleTask() {stopScanBle();mBleCurrentInfo.clearBleResult();mScanCount = 0;TimerUtil.startTask(new TimerTask() {@Overridepublic void run() {if (!mBleCurrentInfo.getBleList().isEmpty() || mScanCount > 0) {TimerUtil.cancelTimer();return;}startScanBle();mScanCount++;}}, 0L, 3000L);}/*** 开始扫描蓝牙*/public void startScanBleFirst() {if (!mBleCurrentInfo.getHisBleList().isEmpty()) {mStartTime = System.currentTimeMillis();startScanBleTask();}}@SuppressLint("MissingPermission")public void stopScanBle() {TimerUtil.cancelTimer();BleCallback.instance.stopScan(mBluetoothAdapter);}/*** 连接GATT*/public void connectGatt(BluetoothDevice bluetoothDevice) {BleCallback.instance.connect(false, bluetoothDevice);}/*** 断开GATT*/@SuppressLint("MissingPermission")public void disConnectGatt(boolean isReconnect) {Log.i(TAG, "断开GATT,是否重连:"  + isReconnect);try {if (mBleCurrentInfo.isConnect()) {if (mOperateGatt != null) {unsubscribeNotify();mOperateGatt.close();}}} catch (Exception e) {Log.i(TAG, e.toString());} finally {for (BleDeviceBean bean: mBleCurrentInfo.getBleList()) {bean.setBleConnect(false);}mBleCurrentInfo.setConnect(false);mOperateGatt = null;mNotifyCharacteristic = null;mWriteCharacteristic = null;if (mBleListener != null) {mBleListener.onConnectSuccess(false);}mIsHeart = false;if (isReconnect) {startConnectThread();}}}/*** 发送消息*/@SuppressLint("MissingPermission")public void sendMessage(byte[] message) {if (!mBleCurrentInfo.isConnect()) {ToastUtil.showToast("蓝牙未连接，请连接蓝牙!", 2000);return;}if (mOperateGatt == null || mWriteCharacteristic == null) {Log.i(TAG, "发送消息失败,未持有相关服务");return;}mWriteCharacteristic.setValue(message);mOperateGatt.writeCharacteristic(mWriteCharacteristic);}public void subscribeNotify() {if (mOperateGatt != null && mNotifyCharacteristic != null) {BleCallback.instance.subscribeNotify(mOperateGatt,mNotifyCharacteristic,UsedUUID.NOTIFY_DESCRIPTOR_UUID);} else {Log.i(TAG, "绑定失败,未持有相关服务");ToastUtil.showToast("绑定失败", 2000);}}public void unsubscribeNotify() {if (mOperateGatt != null && mNotifyCharacteristic != null) {BleCallback.instance.unsubscribeNotify(mOperateGatt, mNotifyCharacteristic, UsedUUID.NOTIFY_DESCRIPTOR_UUID);} else {Log.i(TAG, "解绑失败,未持有相关服务");}}/*** GATT连接成功*/@Overridepublic void onConnectSuccess(BluetoothGatt gatt) {Log.i(TAG, "GATT连接成功");}/*** GATT断开连接*/@Overridepublic void onDisconnect(BluetoothGatt gatt) {if (mOperateGatt != null || !Objects.equals(gatt.getDevice().getAddress(), mOperateGatt.getDevice().getAddress())) {return;}Log.i(TAG, "GATT断开连接");boolean isReconnect = false;if (!mBleCurrentInfo.getBleList().isEmpty() && Objects.equals(gatt.getDevice().getAddress(), mBleCurrentInfo.getBleList().get(0).getBleAddress())) {isReconnect = true;}disConnectGatt(isReconnect);}/*** 发现服务*/@SuppressLint("MissingPermission")@Overridepublic void onServicesDiscovered(BluetoothGatt gatt, List<BluetoothGattService> services) {Log.i(TAG, "发现服务UUID");boolean isNext = false;for (BluetoothGattService service: services) {if (service.getUuid().toString().equals(UsedUUID.SERVICE_UUID.toString())) {Log.i(TAG, "找到SERVICE_UUID");mOperateService = service;mBleGattCharacteristics.clear();mBleGattCharacteristics.addAll(service.getCharacteristics());isNext = true;break;}}if (!isNext) {Log.i(TAG, "未找到指定的服务UUID");disConnectGatt(false);return;}isNext = false;List<BluetoothGattCharacteristic> bleGattCharacteristics = new ArrayList<>(mBleGattCharacteristics);for (BluetoothGattCharacteristic bluetoothGattCharacteristic: bleGattCharacteristics) {if (bluetoothGattCharacteristic.getUuid().toString().equals(UsedUUID.NOTIFY_CHARACTERISTIC_UUID.toString())) {Log.i(TAG, "找到NOTIFY_CHARACTERISTIC_UUID");mNotifyCharacteristic = bluetoothGattCharacteristic;isNext = true;}if (bluetoothGattCharacteristic.getUuid().toString().equals(UsedUUID.WRITE_CHARACTERISTIC_UUID.toString())) {Log.i(TAG, "找到WRITE_CHARACTERISTIC_UUID");mWriteCharacteristic = bluetoothGattCharacteristic;}}if (isNext) {try {Log.i(TAG, "BLE蓝牙连接成功");if (mBleCurrentInfo.isConnect()) {mBleCurrentInfo.setConnect(false);mOperateGatt.close();}for (BleDeviceBean bean: mBleCurrentInfo.getBleList()) {bean.setBleConnect(false);}mOperateGatt = gatt;subscribeNotify();Log.i(TAG, "BLE蓝牙绑定成功");mBleCurrentInfo.setConnect(true);if (mIsFirstConnect) {mBleCurrentInfo.getBleList().get(0).setBleConnect(true);}
//                if (Objects.equals(mBleCurrentInfo.getBleAddress(), gatt.getDevice().getAddress()) && !mBleCurrentInfo.getBleList().isEmpty()) {
//                    mBleCurrentInfo.getBleList().get(0).setBleConnect(true);
//                }mBleCurrentInfo.setConnect(true);mBleCurrentInfo.setBleName(gatt.getDevice().getName());mBleCurrentInfo.setBleAddress(gatt.getDevice().getAddress());mBleCurrentInfo.updateScanBean();if (mDiscoveredListener != null) {mDiscoveredListener.onServicesDiscovered(gatt);}if (mBleListener != null) {mBleListener.onConnectSuccess(true);}} catch (Exception e) {Log.i(TAG, "BLE蓝牙连接异常");disConnectGatt(false);}} else {disConnectGatt(false);}}@Overridepublic void onServicesDiscoverFailed(int status) {Log.i(TAG, "onServicesDiscoverFailed");}@Overridepublic void onServicesChange(BluetoothGatt gatt) {Log.i(TAG, "onServicesChange");}@Overridepublic void onCharacteristicChange(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {mHeartTime = System.currentTimeMillis();Log.i(TAG, Arrays.toString(characteristic.getValue()));mBleListener.onCharacteristicChange(characteristic.getValue());}
}

该蓝牙管理类中采用了心跳来保证蓝牙通讯的稳定性，每当超时未接收到外围设备心跳时，都会开启重连线程，若没有相关心跳协议，可将心跳部分代码去掉。

② BleCallback完整代码：

package com.example.bluetooth.callback;import android.annotation.SuppressLint;
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.BluetoothProfile;
import android.bluetooth.le.BluetoothLeScanner;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanFilter;
import android.bluetooth.le.ScanSettings;
import android.util.Log;import androidx.annotation.NonNull;
import androidx.annotation.RequiresPermission;import com.example.bluetooth.bean.BleDevice;
import com.example.bluetooth.intel.CharacteristicListener;
import com.example.bluetooth.intel.ConnectListener;
import com.example.bluetooth.intel.DescriptorListener;
import com.example.bluetooth.intel.MtuListener;
import com.example.bluetooth.intel.NotifyListener;
import com.example.bluetooth.intel.PhyListener;
import com.example.bluetooth.intel.ReliableListener;
import com.example.bluetooth.intel.RssiListener;
import com.example.bluetooth.util.TimerUtil;
import com.example.bluetooth.util.Utils;import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.TimerTask;
import java.util.UUID;/*** @des: 蓝牙回调类* @date: 2024/9/4* @author: yanghaifeng*/
public class BleCallback extends BluetoothGattCallback {private final static String TAG = "BleCallback";public static BleCallback instance = new BleCallback();private ArrayList<BleDevice> mConnectedBleDeviceList = new ArrayList<>();private ConnectListener mConnectListener = null;private MtuListener mMtuListener = null;private RssiListener mRssiListener = null;private NotifyListener mNotifyListener = null;private CharacteristicListener mCharacteristicListener = null;private PhyListener mPhyListener = null;private ReliableListener mReliableListener = null;private DescriptorListener mDescriptorListener = null;private ScanCallback mScanCallback = null;public ArrayList<BleDevice> getConnectedBleDeviceList() {return mConnectedBleDeviceList;}public void setConnectedBleDeviceList(ArrayList<BleDevice> mConnectedBleDeviceList) {this.mConnectedBleDeviceList = mConnectedBleDeviceList;}public ConnectListener getConnectListener() {return mConnectListener;}public void setConnectListener(ConnectListener mConnectListener) {this.mConnectListener = mConnectListener;}public MtuListener getMtuListener() {return mMtuListener;}public void setMtuListener(MtuListener mMtuListener) {this.mMtuListener = mMtuListener;}public RssiListener getRssiListener() {return mRssiListener;}public void setRssiListener(RssiListener mRssiListener) {this.mRssiListener = mRssiListener;}public NotifyListener getNotifyListener() {return mNotifyListener;}public void setNotifyListener(NotifyListener mNotifyListener) {this.mNotifyListener = mNotifyListener;}public CharacteristicListener getCharacteristicListener() {return mCharacteristicListener;}public void setCharacteristicListener(CharacteristicListener mCharacteristicListener) {this.mCharacteristicListener = mCharacteristicListener;}public PhyListener getPhyListener() {return mPhyListener;}public void setPhyListener(PhyListener mPhyListener) {this.mPhyListener = mPhyListener;}public ReliableListener getReliableListener() {return mReliableListener;}public void setReliableListener(ReliableListener mReliableListener) {this.mReliableListener = mReliableListener;}public DescriptorListener getDescriptorListener() {return mDescriptorListener;}public void setDescriptorListener(DescriptorListener mDescriptorListener) {this.mDescriptorListener = mDescriptorListener;}public ScanCallback getScanCallback() {return mScanCallback;}public void setScanCallback(ScanCallback mScanCallback) {this.mScanCallback = mScanCallback;}/*** 开启ble扫描*/@RequiresPermission(android.Manifest.permission.BLUETOOTH_SCAN)public void startLeScan(BluetoothAdapter bluetoothAdapter,ScanCallback scanCallback,Long scanTime,List<ScanFilter> filters,ScanSettings scanSettings) {try {if (bluetoothAdapter == null) {return;}if (scanCallback == null) {return;}BluetoothLeScanner bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();if (bluetoothLeScanner == null) {return;}if (mScanCallback != null && bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {bluetoothLeScanner.stopScan(mScanCallback);mScanCallback = null;}TimerUtil.cancelDialogTimer();mScanCallback = scanCallback;bluetoothLeScanner.startScan(filters,scanSettings,mScanCallback);TimerUtil.startDialogTask(new TimerTask() {@RequiresPermission(android.Manifest.permission.BLUETOOTH_SCAN)@Overridepublic void run() {if (mScanCallback != null && bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {bluetoothLeScanner.stopScan(mScanCallback);mScanCallback = null;}}}, scanTime);} catch (Exception e) {Log.i(TAG, "蓝牙扫描异常");}}@RequiresPermission(android.Manifest.permission.BLUETOOTH_SCAN)public void stopScan(BluetoothAdapter bluetoothAdapter) {if (bluetoothAdapter.getBluetoothLeScanner() != null && mScanCallback != null&& bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {bluetoothAdapter.getBluetoothLeScanner().stopScan(mScanCallback);}}@SuppressLint("MissingPermission")public void disconnect(BluetoothGatt bluetoothGatt) {bluetoothGatt.disconnect();}@SuppressLint("MissingPermission")public void connect(Boolean isAutoConnect,BluetoothDevice bluetoothDevice) {bluetoothDevice.connectGatt(Utils.getApp(), isAutoConnect, this, BluetoothDevice.TRANSPORT_LE);}@SuppressLint("MissingPermission")public void subscribeNotify(BluetoothGatt bleGatt,BluetoothGattCharacteristic characteristic,UUID descriptorUUID) {bleGatt.setCharacteristicNotification(characteristic, true);BluetoothGattDescriptor clientConfig = characteristic.getDescriptor(descriptorUUID);if (clientConfig != null) {clientConfig.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);bleGatt.writeDescriptor(clientConfig);}}@SuppressLint("MissingPermission")public void unsubscribeNotify(BluetoothGatt bleGatt,BluetoothGattCharacteristic characteristic,UUID descriptorUUID) {try {bleGatt.setCharacteristicNotification(characteristic, false);BluetoothGattDescriptor clientConfig = characteristic.getDescriptor(descriptorUUID);if (clientConfig != null) {clientConfig.setValue(BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE);bleGatt.writeDescriptor(clientConfig);}} catch (Exception e) {Log.i(TAG, e.toString());}}@Overridepublic void onPhyUpdate(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {if (mPhyListener != null) {mPhyListener.onPhyUpdate(gatt, txPhy, rxPhy, status);}}@Overridepublic void onPhyRead(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {if (mPhyListener != null) {mPhyListener.onPhyRead(gatt, txPhy, rxPhy, status);}}@SuppressLint("MissingPermission")@Overridepublic void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {Log.i(TAG, "onConnectionStateChange,status:" + status +",newState:" + newState);switch (newState) {case BluetoothProfile.STATE_CONNECTED:BleDevice bleDevice = new BleDevice();bleDevice.setDeviceName(gatt.getDevice().getName());bleDevice.setMacAddress(gatt.getDevice().getAddress());bleDevice.setGatt(gatt);mConnectedBleDeviceList.add(bleDevice);Log.i(TAG, gatt.getDevice().getAddress() + "已连接");if (mConnectListener != null) {mConnectListener.onConnectSuccess(gatt);}try {Thread.sleep(50);} catch (InterruptedException e) {Log.i(TAG, e.toString());}gatt.discoverServices();break;case BluetoothProfile.STATE_DISCONNECTED:Iterator<BleDevice> iterator = mConnectedBleDeviceList.iterator();while (iterator.hasNext()) {BleDevice next = iterator.next();if (Objects.equals(next.getMacAddress(), gatt.getDevice().getAddress())) {iterator.remove();}}Log.i(TAG, gatt.getDevice().getAddress() + "断开连接");if (mConnectListener != null) {mConnectListener.onDisconnect(gatt);}gatt.close();break;default:break;}}@Overridepublic void onServicesDiscovered(BluetoothGatt gatt, int status) {Log.i(TAG, "onServicesDiscovered,status:" + status);switch (status) {case BluetoothGatt.GATT_SUCCESS:if (!mConnectedBleDeviceList.isEmpty()) {mConnectedBleDeviceList.get(mConnectedBleDeviceList.size() - 1).setServiceList(gatt.getServices());if (mConnectListener != null) {mConnectListener.onServicesDiscovered(gatt, gatt.getServices());}}break;default:if (mConnectListener != null) {mConnectListener.onServicesDiscoverFailed(status);}break;}}@Overridepublic void onCharacteristicRead(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic,int status) {if (mCharacteristicListener != null) {mCharacteristicListener.onCharacteristicRead(gatt, characteristic, status);}}@Overridepublic void onCharacteristicWrite(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic,int status) {if (mCharacteristicListener != null) {mCharacteristicListener.onCharacteristicWrite(gatt, characteristic, status);}}@Overridepublic void onCharacteristicChanged(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic) {if (mNotifyListener != null) {mNotifyListener.onCharacteristicChange(gatt, characteristic);}}@Overridepublic void onDescriptorRead(BluetoothGatt gatt,BluetoothGattDescriptor descriptor,int status) {if (mDescriptorListener != null) {mDescriptorListener.onDescriptorRead(gatt, descriptor, status);}}@Overridepublic void onDescriptorWrite(BluetoothGatt gatt,BluetoothGattDescriptor descriptor,int status) {if (mDescriptorListener != null) {mDescriptorListener.onDescriptorWrite(gatt, descriptor, status);}}@Overridepublic void onReliableWriteCompleted(BluetoothGatt gatt, int status) {if (mReliableListener != null) {mReliableListener.onReliableWriteCompleted(gatt, status);}}@Overridepublic void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {if (mRssiListener != null) {mRssiListener.onReadRemoteRssi(gatt, rssi, status);}}@SuppressLint("MissingPermission")@Overridepublic void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {gatt.discoverServices();if (mMtuListener != null) {mMtuListener.onMtuChange(gatt, mtu, status);}}@Overridepublic void onServiceChanged(@NonNull BluetoothGatt gatt) {if (mConnectListener != null) {mConnectListener.onServicesChange(gatt);}}
}

遇到的问题
1.
问题：
  蓝牙扫描有时候会发现不了设备，多次调用BluetoothLeScanner.startScan后可正常找到。
解决方案：
  为了友好型考虑，开启一个循环Timer，每3秒开启一次蓝牙扫描，如找到设备或扫描次数超过3次，则停止循环。

    private int mScanCount = 0; // 扫描次数public void startScanBleTask() {stopScanBle();mBleCurrentInfo.clearBleResult();mScanCount = 0;TimerUtil.startTask(new TimerTask() {@Overridepublic void run() {if (!mBleCurrentInfo.getBleList().isEmpty() || mScanCount > 0) {TimerUtil.cancelTimer();return;}startScanBle();mScanCount++;}}, 0L, 3000L);}

问题：
  蓝牙连接一段时间后，中心设备Notify属性接收不到外围设备发送的消息，即便断线重连也无法再次受到。
解决方案：
   断开设备后，进行重新扫描，再次连接时，可接收到Notify的消息。若设备需保持长期通讯，可与外围设备建立心跳协议，当中心设备超时未接收到心跳时，进行断线
->扫描->连接操作。

	private Thread mHeartThread = null; // 心跳线程private boolean mIsHeart = false; // 心跳线程运行状态private long mHeartOverTime = 3000L; // 心跳超时时间private long mHeartTime = 0L;private Thread mConnectThread = null; // 重连线程private boolean mIsRunning = false; // 重连线程运行状态long mConnectOverTime = 20 * 1000L; // 重连扫描超时时间/*** 开启心跳线程*/public void startHeartThread() {Log.i(TAG, "开启心跳线程");getHeardThread();mHeartThread.start();}private void getHeardThread() {stopHeartThread();mIsHeart = true;mHeartThread = new Thread(new Runnable() {@Overridepublic void run() {mHeartTime = System.currentTimeMillis();while (mIsHeart) {if (System.currentTimeMillis() - mHeartTime > mHeartOverTime) {Log.i(TAG, "心跳超时");disConnectGatt(true);}}}});}/*** 关闭心跳线程*/public void stopHeartThread() {mIsHeart = false;try {if (mHeartThread != null) {mHeartThread.join();mHeartThread = null;}} catch (InterruptedException i) {Log.i(TAG, i.toString());}}/*** 开启重连线程*/public void startConnectThread() {Log.i(TAG, "开启重连线程");getConnectThread();mConnectThread.start();}private void getConnectThread() {mIsHeart = false;stopConnectThread();mIsRunning = true;mConnectThread = new Thread(new Runnable() {@Overridepublic void run() {startScanBleTask();long time = System.currentTimeMillis();Log.i(TAG, "开始尝试重连");while (mIsRunning && System.currentTimeMillis() - time < mConnectOverTime) {List<BleDeviceBean> beans = new ArrayList<>(mBleCurrentInfo.getBleList());for (BleDeviceBean bean: beans) {try {if (Objects.equals(bean.getBleAddress(), mBleCurrentInfo.getBleAddress())) {Log.i(TAG, "找到重连address:" + mBleCurrentInfo.getBleAddress());int count = 0;Log.i(TAG, "第${count + 1}次尝试连接");connectGatt(getRemoteDevice(bean.getBleAddress()));count++;long currentTime = System.currentTimeMillis();while (count < 3) {if (!mIsRunning) {return;}if (mBleCurrentInfo.isConnect()) {break;}if (System.currentTimeMillis() - currentTime < 5000) {continue;}Log.i(TAG, "第${count + 1}次尝试连接");connectGatt(getRemoteDevice(bean.getBleAddress()));currentTime = System.currentTimeMillis();count++;}mIsRunning = false;break;}} catch (Exception e) {Log.i(TAG, e.toString());}}}}});}/*** 关闭重连线程*/public void stopConnectThread() {mIsRunning = false;try {if (mConnectThread != null) {mConnectThread.join();mConnectThread = null;}} catch (InterruptedException i) {Log.i(TAG, i.toString());} finally {stopScanBle();}}

蓝牙测试demo

本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：http://www.mzph.cn/pingmian/53875.shtml

如若内容造成侵权/违法违规/事实不符，请联系多彩编程网进行投诉反馈email:809451989@qq.com，一经查实，立即删除！

相关文章

华为OD机试 - 推荐多样性（Python/JS/C/C++ 2024 E卷 100分）

华为OD机试 - 推荐多样性（Python/JS/C/C++ 2024 E卷 100分）

华为OD机试 2024E卷题库疯狂收录中&#xff0c;刷题点这里 专栏导读 本专栏收录于《华为OD机试真题&#xff08;Python/JS/C/C&#xff09;》。 刷的越多&#xff0c;抽中的概率越大&#xff0c;私信哪吒&#xff0c;备注华为OD&#xff0c;加入华为OD刷题交流群&#xff0c;…
阅读更多...
气压测试实验（用IIC）

气压测试实验（用IIC）

I2C: 如果没有I2c这类总线&#xff0c;连接方法可能会如下图&#xff1a; 单片机所有的通讯协议&#xff0c;无非是建立在引脚&#xff08;高低电平的变换高低电平持续的时间&#xff09;这二者的组合上&#xff0c;i2c 多了一个clock线&#xff0c;负责为数据传输打节拍。 (i2…
阅读更多...
C#使用TCP-S7协议读写西门子PLC(四)

C#使用TCP-S7协议读写西门子PLC(四)

接上一篇，我们连接PLC并握手成功，并且封装生成读写PLC的命令 C#使用TCP-S7协议读写西门子PLC(三)-CSDN博客 这里我们进行读写基础数据类型、读取DB块的字符串、宽字符串、以及一系列连续数组。 新建部分类文件SiemensS7ProtocolUtil.Integrated.cs 主要方法 读取任意连续…
阅读更多...
C和指针：函数

C和指针：函数

函数定义 函数体就是一个代码块&#xff0c;它在函数被调用时执行。 类型 函数名(形式参数) 代码块 与函数定义相反&#xff0c;函数声明出现在函数被调用的地方。 函数声明 编译器是如何知道该函数期望接受的是什么类型和多少数量的参数。 原型 int *find_int( int key…
阅读更多...
ASPICE评估全流程解析：汽车软件开发组织能力的系统化评估

ASPICE评估全流程解析：汽车软件开发组织能力的系统化评估

ASPICE&#xff08;Automotive SPICE&#xff09;评估的过程是一个系统化和详尽的流程&#xff0c;旨在评估汽车软件开发组织在软件开发过程方面的能力。 以下是ASPICE评估过程的详细描述&#xff1a; 1. 评估准备阶段 a. 确定评估目标和范围 明确评估的目标&#xff0c;如评…
阅读更多...
同时拥有独显和核显，怎么让应用程序选择使用哪个GPU？

同时拥有独显和核显，怎么让应用程序选择使用哪个GPU？

看你现在使用的是核显还是独显 勾选上GPU引擎选项&#xff0c;后面便会标识你所使用的是哪种显卡&#xff0c;如果是独立显卡&#xff0c;就可以免去后续的操作&#xff1b;如果不是&#xff0c;那么请继续接下来的操作。 将你需要使用独显的程序换成gpu1&#xff08;独显&am…
阅读更多...
Spring Boot 注解探秘：JSON 处理的魔法世界

Spring Boot 注解探秘：JSON 处理的魔法世界

Spring Boot 注解探秘&#xff1a;JSON 处理的魔法世界 首发2024-09-11 16:43潘多编程 在当今这个数据驱动的世界里&#xff0c;JSON&#xff08;JavaScript Object Notation&#xff09;已经成为了数据交换的事实标准。无论是前端与后端的通信&#xff0c;还是系统间的服务交…
阅读更多...
C# List定义和常用方法

C# List定义和常用方法

栏目总目录 List的定义 列表&#xff08;List&#xff09;是一种常用的集合类型&#xff0c;它属于System.Collections.Generic命名空间。列表是一个有序集合&#xff0c;可以包含重复的元素&#xff0c;并且可以根据索引访问元素。 List< T > List<T> 是一个泛…
阅读更多...
佰朔资本：未来钢铁行业产业格局有望稳中趋好

佰朔资本：未来钢铁行业产业格局有望稳中趋好

组织指出&#xff0c;未来钢铁作业工业格式有望稳中趋好&#xff0c;叠加当时部分公司已经处于价值小看区域&#xff0c;现阶段仍具结构性出资机会&#xff0c;尤其是拥有较高毛利率水平的优特钢企业和本钱管控力度强、具有规划效应的龙头钢企&#xff0c;未来存在估值修改的机…
阅读更多...
git submodule sync

git submodule sync

git submodule 是 Git 提供的一种功能&#xff0c;用于在一个 Git 仓库中嵌套另一个 Git 仓库。它可以帮助管理和跟踪外部项目或依赖项&#xff0c;特别是在以下场景中非常有用&#xff1a; 1. 管理外部依赖 当你的项目依赖于其他外部项目或库时&#xff0c;可以使用 git sub…
阅读更多...
JavaEE:文件操作

JavaEE:文件操作

文章目录 文件操作和IO文件系统操作File介绍属性构造方法方法 代码演示前四个listmkdirrenameTo 文件操作和IO 文件系统操作 创建文件,删除文件,创建目录,重命名… Java中有一个类,可以帮我们完成上述操作. 这个类叫做File类. File介绍 属性 这个表格描述了文件路径的分隔符…
阅读更多...
应急响应实战---是谁修改了我的密码？

应急响应实战---是谁修改了我的密码？

前言&#xff1a;此次应急响应为真实案例&#xff0c;客户反馈无法通过密码登录服务器&#xff0c;疑似服务器被入侵 0x01 如何找回密码&#xff1f; 客户服务器为windows server2019&#xff0c;运维平台为PVE平台&#xff1b;实际上无论是windows系统或者是linux系统&#…
阅读更多...
ROS2 Control controller_interface说明

ROS2 Control controller_interface说明

ROS2 Control controller_interface说明 文章目录 前言controller_interface说明Class ControllerInterfaceBaseClass ControllerInterface说明Class ChainableControllerInterface说明 semantic_components说明Class ForceTorqueSensorClass IMUSensorClass RangeSensor 参考 …
阅读更多...
Jacoco的XML报告详解

Jacoco的XML报告详解

使用jacococli完成jacoco测试报告生成后，会看到有一个.xml结尾的文件，这个就是xml格式的覆盖率报告。除了xml还有csv、html格式的报告，本文进介绍xml报告。 DTD文件 在介绍jacoco的xml报告之前，我们应该先看一下对应的DTD文件的内容。(DTD的全称为Document Type Definitio…
阅读更多...
Java应用的数据库连接池连接池性能测试

Java应用的数据库连接池连接池性能测试

Java应用的数据库连接池连接池性能测试 大家好&#xff0c;我是微赚淘客返利系统3.0的小编&#xff0c;是个冬天不穿秋裤&#xff0c;天冷也要风度的程序猿&#xff01; 数据库连接池的性能测试是确保Java应用能够高效运行的关键步骤。性能测试可以帮助我们评估连接池在高并发…
阅读更多...
Rust 所有权 借用与引用

Rust 所有权 借用与引用

文章目录 发现宝藏1. 所有权&#xff08;Ownership&#xff09;2. 引用&#xff08;References&#xff09;2.1 不可变引用2.2 可变引用2.3 引用的规则 3. 悬垂引用&#xff08;Dangling References&#xff09;4. 借用&#xff08;Borrowing&#xff09;结论 发现宝藏 前些天…
阅读更多...
个人学习笔记7-5：动手学深度学习pytorch版-李沐

个人学习笔记7-5：动手学深度学习pytorch版-李沐

#人工智能# #深度学习# #语义分割# #计算机视觉# #神经网络# 计算机视觉 13.10 转置卷积 例如&#xff0c;卷积层和汇聚层&#xff0c;通常会减少下采样输入图像的空间维度&#xff08;高和宽&#xff09;。然而如果输入和输出图像的空间维度相同&#xff0c;在以像素级分类…
阅读更多...
【App】React Native

【App】React Native

React Native 的优势&#xff1a; 开发体验好 用统一的代码规范开发移动端程序&#xff0c;不用关注移动端的差异.开发成本低 开发一次&#xff0c;可以生成 Android 和 IOS 俩个系统上的 App学习成本低 只要掌握 JavaScript 和 React 就可以进行移动端开发 React Native 的不…
阅读更多...
【物联网技术大作业】设计一个智能家居的应用场景

【物联网技术大作业】设计一个智能家居的应用场景

前言&#xff1a; 本人的物联网技术的期末大作业&#xff0c;希望对你有帮助。 目录 大作业设计题 &#xff08;1&#xff09;智能家居的概述。 &#xff08;2&#xff09;介绍智能家居应用。要求至少5个方面的应用&#xff0c;包括每个应用所采用的设备&#xff0c;性能&am…
阅读更多...
2023级JavaScript与jQuery

2023级JavaScript与jQuery

第三课&#xff1a;JavaScript对象编程 一.预习笔记 1.Date对象 对象创建&#xff1a;var myDatenew Date() 输出显示当前日期的标准时间 对象创建&#xff1a;var myDatenew Date(“2024/09/14”) 对象创建&#xff1a;var myDatenew Date(2024,9,14) 当前对象创建时&…
阅读更多...
最新文章

Copyright @ 2022~2023