Android 广播监听USB插拔

AndroidManifest.xml

<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /><receiver android:name=".receiver.UsbReceiver">    <intent-filter>        <action android:name="android.intent.action.MEDIA_MOUNTED" />        <action android:name="android.intent.action.MEDIA_UNMOUNTED" />        <data android:scheme="file" />    </intent-filter></receiver>

UsbReceiver.java

public class UsbReceiver extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        UsbManager.getInstance().usbObserveReceive(context, intent, Intent.ACTION_MEDIA_MOUNTED.equals(intent.getAction())                ? Constants.USB_TYPE_ATTACH : Constants.USB_TYPE_DETACH);    }}

UsbInfo.java

public class UsbInfo {    // uuid    public String uuid;    // uri    public Uri uri;    // u盘类型    public String fsType;    // u盘名称    public String fsLabel;    // u盘路径    public String path;    // u盘路径    public String internalPath;    // 已格式化显示的可用空间大小    public String availableSize;    // 已格式化显示的总空间大小    public String totalSize;    @Override    public String toString() {        return "UsbInfo{" +                "uuid='" + uuid + '\'' +                ", uri=" + uri +                ", fsType='" + fsType + '\'' +                ", fsLabel='" + fsLabel + '\'' +                ", path='" + path + '\'' +                ", internalPath='" + internalPath + '\'' +                ", availableSize='" + availableSize + '\'' +                ", totalSize='" + totalSize + '\'' +                '}';    }}

UsbObserveType .java

public class Constants {public static final int USB_TYPE_ATTACH = 0x3001;public static final int USB_TYPE_DETACH = 0x3002;}@IntDef(flag = true, value = {        Constants.USB_TYPE_ATTACH, Constants.USB_TYPE_DETACH})public @interface UsbObserveType {}

UsbManager.java

public class UsbManager {    private static final String TAG = "UsbManager";    private Set<UsbInfo> mUsbInfos = new LinkedHashSet<>();    private List<OnUsbReceiveListener> mOnUsbReceiveListeners = new LinkedList<>();    private static class UsbManagerHolder {        private static final UsbManager INSTANCE = new UsbManager();    }    public static UsbManager getInstance() {        return UsbManagerHolder.INSTANCE;    }    public Set<UsbInfo> getUsbInfos(Context context) {        if (mUsbInfos.size() == 0)            return queryUsbInfos(context);        return mUsbInfos;    }    public void registerUsbReceiveListener(OnUsbReceiveListener listener) {        mOnUsbReceiveListeners.add(listener);    }    public void unregisterUsbReceiveListener(OnUsbReceiveListener listener) {        mOnUsbReceiveListeners.remove(listener);    }    public void usbObserveReceive(Context context, Intent intent, @UsbObserveType int usbObserveType) {        Set<UsbInfo> tUsbInfos = queryUsbInfos(context);        UsbInfo attachUsbInfo = new UsbInfo();        if (usbObserveType == Constants.USB_TYPE_ATTACH) {            for (UsbInfo usbInfo : tUsbInfos) {                if (intent.getData().getPath().equals(usbInfo.path)) {                    usbInfo.uri = intent.getData();                    attachUsbInfo = usbInfo;                    mUsbInfos.add(attachUsbInfo);                    break;                }            }        } else {            for (UsbInfo usbInfo : mUsbInfos) {                if (usbInfo.uri.equals(intent.getData())) {                    attachUsbInfo = usbInfo;                    mUsbInfos.remove(attachUsbInfo);                    break;                }            }        }        Log.i(TAG, "intent = " + intent + ", usbInfos = " + mUsbInfos);        for (OnUsbReceiveListener listener : mOnUsbReceiveListeners) {            if (listener != null) {                listener.onUsbReceive(usbObserveType, mUsbInfos, attachUsbInfo);            }        }    }    public Set<UsbInfo> queryUsbInfos(Context context) {        Set<UsbInfo> usbInfos = new LinkedHashSet<>();        try {            StorageManager sm = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);            Class clazz = Class.forName("android.os.storage.StorageManager");            Method methodGetVolumes = clazz.getMethod("getVolumes");            List<?> volumeInfos = (List<?>) methodGetVolumes.invoke(sm);            @SuppressLint("PrivateApi") Class volumeInfoClazz = Class.forName("android.os.storage.VolumeInfo");            Method methodGetFsUUID = volumeInfoClazz.getMethod("getFsUuid");            Field fieldFsType = volumeInfoClazz.getDeclaredField("fsType");            Field fieldFsLabelField = volumeInfoClazz.getDeclaredField("fsLabel");            Field fieldPath = volumeInfoClazz.getDeclaredField("path");            Field fieldInternalPath = volumeInfoClazz.getDeclaredField("internalPath");            if (volumeInfos != null) {                for (Object volumeInfo : volumeInfos) {                    String uuid = (String) methodGetFsUUID.invoke(volumeInfo);                    if (uuid != null) {                        UsbInfo usbInfo = new UsbInfo();                        usbInfo.uuid = uuid;                        usbInfo.fsType = (String) fieldFsType.get(volumeInfo);                        usbInfo.fsLabel = (String) fieldFsLabelField.get(volumeInfo);                        usbInfo.path = (String) fieldPath.get(volumeInfo);                        usbInfo.internalPath = (String) fieldInternalPath.get(volumeInfo);                        try {                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {                                StatFs statFs = new StatFs(usbInfo.path);                                usbInfo.availableSize = Formatter.formatFileSize(context, statFs.getAvailableBytes());                                usbInfo.totalSize = Formatter.formatFileSize(context, statFs.getTotalBytes());                            }                        } catch (IllegalArgumentException e) {                            e.printStackTrace();                        }                        usbInfos.add(usbInfo);                    }                }            }        } catch (Exception e) {            e.printStackTrace();        }        return usbInfos;    }    public interface OnUsbReceiveListener {        void onUsbReceive(@UsbObserveType int usbObserveType, Set<UsbInfo> usbInfos, UsbInfo currUsbInfo);    }}

使用

public class TestActivity extends AppCompatActivity implements UsbManager.OnUsbReceiveListener {    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        UsbManager.getInstance().registerUsbReceiveListener(this);    } @Override    protected void onDestroy() {        UsbManager.getInstance().unregisterUsbReceiveListener(this);        super.onDestroy();    }@Override    public void onUsbReceive(int usbObserveType, Set<UsbInfo> usbInfos, UsbInfo currUsbInfo) {    // 接收处理    }}

注意事项：

在实际项目开发过程中，比如在TV机顶盒开发，使用以上方法是可以较为准确的监听到USB的插拔，但是如果尝试将数据写入USB，将会出现无法写入提示 permission denied，这个时候需要去修改源码。

从源码中定位到 frameworks\base\services\core\java\com\android\server\pm\PackageManagerService.java，搜索到 systemReady() 这个方法，加入以下几句代码：

StorageManagerInternal StorageManagerInternal = LocalServices.getService(StorageManagerInternal.class);StorageManagerInternal.addExternalStoragePolicy(        new StorageManagerInternal.ExternalStorageMountPolicy() {    @Override    public int getMountMode(int uid, String packageName) {        if (Process.isIsolated(uid)) {            return Zygote.MOUNT_EXTERNAL_NONE;        }        // 添加允许写权限---开始if (checkUidPermission(WRITE_MEDIA_STORAGE, uid) == PERMISSION_GRANTED) {            return Zygote.MOUNT_EXTERNAL_DEFAULT;        }        // 添加允许写权限---结束        if (checkUidPermission(READ_EXTERNAL_STORAGE, uid) == PERMISSION_DENIED) {            return Zygote.MOUNT_EXTERNAL_DEFAULT;        }        if (checkUidPermission(WRITE_EXTERNAL_STORAGE, uid) == PERMISSION_DENIED) {            return Zygote.MOUNT_EXTERNAL_READ;        }        return Zygote.MOUNT_EXTERNAL_WRITE;    }    @Override    public boolean hasExternalStorage(int uid, String packageName) {        return true;    }});

然后在app的 AndroidManifest.xml 加入权限即可：

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

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