Utilice el archivo de recursos device_filter.xml para filtrar resultados de enumeración USB

La funcionalidad de filtrado se implementa en frameworks/base/services/java/com/android/server/usb/UsbSettingsManager.java , pero éstos son desafortunadamente privados. He extraído parte de su implementación, se puede utilizar de esta manera:

 private void scanDevices() { ArrayList<UsbDevice> devices; try { devices = UsbDeviceFilter.getMatchingHostDevices(this, R.xml.wifi_devices); } catch (Exception e) { Log.w(TAG, "Failed to parse devices.xml: " + e.getMessage()); return; } for (UsbDevice device : devices) { Log.d(TAG, "Matched device " + device); } } 

Actualmente solo se aceptan dispositivos host, pero agregar soporte para dispositivos accesorios es trivial.

UsbDeviceFilter.xml:

 import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import android.content.Context; import android.content.res.XmlResourceParser; import android.hardware.usb.UsbDevice; import android.hardware.usb.UsbInterface; import android.hardware.usb.UsbManager; /** * Utility to test whether a USB device is accepted by a device filter. Heavily * based on com.android.server.usb.UsbSettingsManager. * @author Peter Wu <[email protected]> */ public class UsbDeviceFilter { private final List<DeviceFilter> hostDeviceFilters; public UsbDeviceFilter(XmlPullParser parser) throws XmlPullParserException, IOException { hostDeviceFilters = new ArrayList<UsbDeviceFilter.DeviceFilter>(); int eventType = parser.getEventType(); while (eventType != XmlPullParser.END_DOCUMENT) { String tagName = parser.getName(); if ("usb-device".equals(tagName) && parser.getEventType() == XmlPullParser.START_TAG) { hostDeviceFilters.add(DeviceFilter.read(parser)); } eventType = parser.next(); } } public boolean matchesHostDevice(UsbDevice device) { for (DeviceFilter filter : hostDeviceFilters) { if (filter.matches(device)) { return true; } } return false; } /** * Get a list of connected USB Host devices matching the devices filter. * @param ctx A non-null application context. * @param resourceId The resource ID pointing to a devices filter XML file. * @return A list of connected host devices matching the filter. * @throws XmlPullParserException * @throws IOException */ public static ArrayList<UsbDevice> getMatchingHostDevices(Context ctx, int resourceId) throws XmlPullParserException, IOException { UsbManager usbManager = (UsbManager) ctx .getSystemService(Context.USB_SERVICE); XmlResourceParser parser = ctx.getResources().getXml(resourceId); UsbDeviceFilter devFilter; try { devFilter = new UsbDeviceFilter(parser); } finally { parser.close(); } ArrayList<UsbDevice> matchedDevices = new ArrayList<UsbDevice>(); for (UsbDevice device : usbManager.getDeviceList().values()) { if (devFilter.matchesHostDevice(device)) { matchedDevices.add(device); } } return matchedDevices; } public static class DeviceFilter { // USB Vendor ID (or -1 for unspecified) public final int mVendorId; // USB Product ID (or -1 for unspecified) public final int mProductId; // USB device or interface class (or -1 for unspecified) public final int mClass; // USB device subclass (or -1 for unspecified) public final int mSubclass; // USB device protocol (or -1 for unspecified) public final int mProtocol; private DeviceFilter(int vid, int pid, int clasz, int subclass, int protocol) { mVendorId = vid; mProductId = pid; mClass = clasz; mSubclass = subclass; mProtocol = protocol; } private static DeviceFilter read(XmlPullParser parser) { int vendorId = -1; int productId = -1; int deviceClass = -1; int deviceSubclass = -1; int deviceProtocol = -1; int count = parser.getAttributeCount(); for (int i = 0; i < count; i++) { String name = parser.getAttributeName(i); // All attribute values are ints int value = Integer.parseInt(parser.getAttributeValue(i)); if ("vendor-id".equals(name)) { vendorId = value; } else if ("product-id".equals(name)) { productId = value; } else if ("class".equals(name)) { deviceClass = value; } else if ("subclass".equals(name)) { deviceSubclass = value; } else if ("protocol".equals(name)) { deviceProtocol = value; } } return new DeviceFilter(vendorId, productId, deviceClass, deviceSubclass, deviceProtocol); } private boolean matches(int clasz, int subclass, int protocol) { return ((mClass == -1 || clasz == mClass) && (mSubclass == -1 || subclass == mSubclass) && (mProtocol == -1 || protocol == mProtocol)); } public boolean matches(UsbDevice device) { if (mVendorId != -1 && device.getVendorId() != mVendorId) return false; if (mProductId != -1 && device.getProductId() != mProductId) return false; // check device class/subclass/protocol if (matches(device.getDeviceClass(), device.getDeviceSubclass(), device.getDeviceProtocol())) return true; // if device doesn't match, check the interfaces int count = device.getInterfaceCount(); for (int i = 0; i < count; i++) { UsbInterface intf = device.getInterface(i); if (matches(intf.getInterfaceClass(), intf.getInterfaceSubclass(), intf.getInterfaceProtocol())) return true; } return false; } } }