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Android_ UEventObserver_监听USB插拔
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http://blog.csdn.net/zimo2013/article/details/38950363
1.简介
最近做一个项目，主要通过usb完成pc与Android端的数据传输。但是根据api提供的无法监听usb的插拔，有解释为不同版本会存在BUG。本打算放弃跳过监听usb，改为在连上usb后pc点击按钮发出一个广播来主动打开Android端的应用程序，然后通过socket完成数据交互。这里主要通过UEventObserver，而该类位于/frameworks/base/core/java/android/os/UEventObserver.java中，位于framework框架。需要手动导入编译好的frameworks，下载frameworks.jar。
2.如何导入frameworks.jar
在工程的Build Path 中，Add External JARs中选择frameworks.jar，然后需要最好配置Order中将frameworks.jar置前，对于定制的frameworks也可以这样导入。
3.实现UEventObserver
public class MyService extends Service {
private final static String TAG = SMSService.class.getSimpleName();
private UsbUEventObserver usbObserver = null;
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
super.onCreate();
LogUtil.d(TAG, "onCreate()");
usbObserver = new UsbUEventObserver();
usbObserver.startObserving(USB_STATE_MATCH);
usbObserver.startObserving(ACCESSORY_START_MATCH);
}
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent != null) {
//
}
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
LogUtil.d(TAG, "onDestroy()");
if (usbObserver != null) {
usbObserver.stopObserving();
}
super.onDestroy();
}
private static final String USB_STATE_MATCH = "DEVPATH=/devices/virtual/android_usb/android0";
private static final String ACCESSORY_START_MATCH = "DEVPATH=/devices/virtual/misc/usb_accessory";
private class UsbUEventObserver extends UEventObserver {
@Override
public void onUEvent(final UEventObserver.UEvent event) {
LogUtil.i(TAG, "usb:" + event.toString());
final String state = event.get("USB_STATE");
final String accessory = event.get("ACCESSORY");
if (state != null) {
// mHandler.updateState(state);
if (state.equalsIgnoreCase("CONNECTED")) {
Intent intent2 = new Intent(getApplicationContext(), MainActivity.class);
intent2.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplicationContext().startActivity(intent2);
BroadUtil.sendBroadcastConnected(getApplicationContext(),
Constants.ConnectedType.USB_CONNECTED);
} else if (state.toUpperCase().contains("DISCONNECTED")) {
BroadUtil.sendBroadcastConnected(getApplicationContext(),
Constants.ConnectedType.USB_DISCONNECTED);
}
} else if ("START".equals(accessory)) {
// startAccessoryMode();
}
}
};
}4.附UsbDeviceManager源码
/**
* UsbDeviceManager manages USB state in device mode.
*/
public class UsbDeviceManager {
private static final String TAG = UsbDeviceManager.class.getSimpleName();
private static final boolean DEBUG = false;
private static final String USB_STATE_MATCH =
"DEVPATH=/devices/virtual/android_usb/android0";
private static final String ACCESSORY_START_MATCH =
"DEVPATH=/devices/virtual/misc/usb_accessory";
private static final String FUNCTIONS_PATH =
"/sys/class/android_usb/android0/functions";
private static final String STATE_PATH =
"/sys/class/android_usb/android0/state";
private static final String MASS_STORAGE_FILE_PATH =
"/sys/class/android_usb/android0/f_mass_storage/lun/file";
private static final String RNDIS_ETH_ADDR_PATH =
"/sys/class/android_usb/android0/f_rndis/ethaddr";
private static final int MSG_UPDATE_STATE = 0;
private static final int MSG_ENABLE_ADB = 1;
private static final int MSG_SET_CURRENT_FUNCTION = 2;
private static final int MSG_SYSTEM_READY = 3;
private static final int MSG_BOOT_COMPLETED = 4;
// Delay for debouncing USB disconnects.
// We often get rapid connect/disconnect events when enabling USB functions,
// which need debouncing.
private static final int UPDATE_DELAY = 1000;
private UsbHandler mHandler;
private boolean mBootCompleted;
private final Context mContext;
private final ContentResolver mContentResolver;
private final UsbSettingsManager mSettingsManager;
private NotificationManager mNotificationManager;
private final boolean mHasUsbAccessory;
private boolean mUseUsbNotification;
private boolean mAdbEnabled;
private class AdbSettingsObserver extends ContentObserver {
public AdbSettingsObserver() {
super(null);
}
@Override
public void onChange(boolean selfChange) {
boolean enable = (Settings.Secure.getInt(mContentResolver,
Settings.Secure.ADB_ENABLED, 0) > 0);
mHandler.sendMessage(MSG_ENABLE_ADB, enable);
}
}
/*
* Listens for uevent messages from the kernel to monitor the USB state
*/
private final UEventObserver mUEventObserver = new UEventObserver() {
@Override
public void onUEvent(UEventObserver.UEvent event) {
if (DEBUG) Slog.v(TAG, "USB UEVENT: " + event.toString());
String state = event.get("USB_STATE");
String accessory = event.get("ACCESSORY");
if (state != null) {
mHandler.updateState(state);
} else if ("START".equals(accessory)) {
if (DEBUG) Slog.d(TAG, "got accessory start");
setCurrentFunction(UsbManager.USB_FUNCTION_ACCESSORY, false);
}
}
};
public UsbDeviceManager(Context context, UsbSettingsManager settingsManager) {
mContext = context;
mContentResolver = context.getContentResolver();
mSettingsManager = settingsManager;
PackageManager pm = mContext.getPackageManager();
mHasUsbAccessory = pm.hasSystemFeature(PackageManager.FEATURE_USB_ACCESSORY);
initRndisAddress();
// create a thread for our Handler
HandlerThread thread = new HandlerThread("UsbDeviceManager",
Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mHandler = new UsbHandler(thread.getLooper());
if (nativeIsStartRequested()) {
if (DEBUG) Slog.d(TAG, "accessory attached at boot");
setCurrentFunction(UsbManager.USB_FUNCTION_ACCESSORY, false);
}
}
public void systemReady() {
if (DEBUG) Slog.d(TAG, "systemReady");
mNotificationManager = (NotificationManager)
mContext.getSystemService(Context.NOTIFICATION_SERVICE);
// We do not show the USB notification if the primary volume supports mass storage.
// The legacy mass storage UI will be used instead.
boolean massStorageSupported = false;
StorageManager storageManager = (StorageManager)
mContext.getSystemService(Context.STORAGE_SERVICE);
StorageVolume[] volumes = storageManager.getVolumeList();
if (volumes.length > 0) {
massStorageSupported = volumes[0].allowMassStorage();
}
mUseUsbNotification = !massStorageSupported;
// make sure the ADB_ENABLED setting value matches the current state
Settings.Secure.putInt(mContentResolver, Settings.Secure.ADB_ENABLED, mAdbEnabled ? 1 : 0);
mHandler.sendEmptyMessage(MSG_SYSTEM_READY);
}
private static void initRndisAddress() {
// configure RNDIS ethernet address based on our serial number using the same algorithm
// we had been previously using in kernel board files
final int ETH_ALEN = 6;
int address[] = new int[ETH_ALEN];
// first byte is 0x02 to signify a locally administered address
address[0] = 0x02;
String serial = SystemProperties.get("ro.serialno", "1234567890ABCDEF");
int serialLength = serial.length();
// XOR the USB serial across the remaining 5 bytes
for (int i = 0; i < serialLength; i++) {
address[i % (ETH_ALEN - 1) + 1] ^= (int)serial.charAt(i);
}
String addrString = String.format("%02X:%02X:%02X:%02X:%02X:%02X",
address[0], address[1], address[2], address[3], address[4], address[5]);
try {
FileUtils.stringToFile(RNDIS_ETH_ADDR_PATH, addrString);
} catch (IOException e) {
Slog.e(TAG, "failed to write to " + RNDIS_ETH_ADDR_PATH);
}
}
private static String addFunction(String functions, String function) {
if (!containsFunction(functions, function)) {
if (functions.length() > 0) {
functions += ",";
}
functions += function;
}
return functions;
}
private static String removeFunction(String functions, String function) {
String[] split = functions.split(",");
for (int i = 0; i < split.length; i++) {
if (function.equals(split[i])) {
split[i] = null;
}
}
StringBuilder builder = new StringBuilder();
for (int i = 0; i < split.length; i++) {
String s = split[i];
if (s != null) {
if (builder.length() > 0) {
builder.append(",");
}
builder.append(s);
}
}
return builder.toString();
}
private static boolean containsFunction(String functions, String function) {
int index = functions.indexOf(function);
if (index < 0) return false;
if (index > 0 && functions.charAt(index - 1) != ',') return false;
int charAfter = index + function.length();
if (charAfter < functions.length() && functions.charAt(charAfter) != ',') return false;
return true;
}
private final class UsbHandler extends Handler {
// current USB state
private boolean mConnected;
private boolean mConfigured;
private String mCurrentFunctions;
private String mDefaultFunctions;
private UsbAccessory mCurrentAccessory;
private int mUsbNotificationId;
private boolean mAdbNotificationShown;
private final BroadcastReceiver mBootCompletedReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
if (DEBUG) Slog.d(TAG, "boot completed");
mHandler.sendEmptyMessage(MSG_BOOT_COMPLETED);
}
};
public UsbHandler(Looper looper) {
super(looper);
try {
// persist.sys.usb.config should never be unset. But if it is, set it to "adb"
// so we have a chance of debugging what happened.
mDefaultFunctions = SystemProperties.get("persist.sys.usb.config", "adb");
// sanity check the sys.usb.config system property
// this may be necessary if we crashed while switching USB configurations
String config = SystemProperties.get("sys.usb.config", "none");
if (!config.equals(mDefaultFunctions)) {
Slog.w(TAG, "resetting config to persistent property: " + mDefaultFunctions);
SystemProperties.set("sys.usb.config", mDefaultFunctions);
}
mCurrentFunctions = mDefaultFunctions;
String state = FileUtils.readTextFile(new File(STATE_PATH), 0, null).trim();
updateState(state);
mAdbEnabled = containsFunction(mCurrentFunctions, UsbManager.USB_FUNCTION_ADB);
// Upgrade step for previous versions that used persist.service.adb.enable
String value = http://www.mamicode.com/SystemProperties.get("persist.service.adb.enable", "");>Android_ UEventObserver_监听USB插拔
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