Android Java framework各种各样的修改经验

  // Temporary mapping USB device name to list of UIDs with permissions for the device
    private final HashMap<String, SparseBooleanArray> mDevicePermissionMap =
            new HashMap<>();
    // Temporary mapping UsbAccessory to list of UIDs with permissions for the accessory
    private final HashMap<UsbAccessory, SparseBooleanArray> mAccessoryPermissionMap =
            new HashMap<>();

两个hashmap分别储存的uid和对应的usbdevice,只要存在即允许了权限
    public boolean hasPermission(UsbDevice device, String packageName, int uid) {
        synchronized (mLock) {
            if (isCameraDevicePresent(device)) {
		//camera权限,usb camera需要额外的camera权限
                if (!isCameraPermissionGranted(packageName, uid)) {
                    return false;
                }
            }
		//如果是系统uid,或者mDisablePermissionDialogs 设置禁用usb权限询问框,则默认拥有权限
            if (uid == Process.SYSTEM_UID || mDisablePermissionDialogs) {
                return true;
            }
		//获取对应usbdevice的已允许权限uid,如果uid存在则判断拥有权限
            SparseBooleanArray uidList = mDevicePermissionMap.get(device.getDeviceName());
            if (uidList == null) {
                return false;
            }
            return uidList.get(uid);
 
        }
    }

 private static final String ACCOUNT_TYPE_SIM = "SIM Account";
 private static final String ACCOUNT_TYPE_USIM = "USIM Account";
 private static final String ACCOUNT_TYPE_RUIM = "RUIM Account";
 private static final String ACCOUNT_TYPE_CSIM = "CSIM Account";

private static boolean isAccountTypeIccCard(String accountTypeString) {
     boolean isIccCardAccount = (ACCOUNT_TYPE_SIM.equals(accountTypeString)
             || ACCOUNT_TYPE_USIM.equals(accountTypeString)
             || ACCOUNT_TYPE_RUIM.equals(accountTypeString)
             || ACCOUNT_TYPE_CSIM.equals(accountTypeString));
     //Log.d(TAG, "account " + accountTypeString + " is IccCard? " + isIccCardAccount);
     return isIccCardAccount;
 }