| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.net.nsd; |
| |
| import static com.android.internal.util.Preconditions.checkArgument; |
| import static com.android.internal.util.Preconditions.checkNotNull; |
| import static com.android.internal.util.Preconditions.checkStringNotEmpty; |
| |
| import android.annotation.SdkConstant; |
| import android.annotation.SdkConstant.SdkConstantType; |
| import android.annotation.SystemService; |
| import android.content.Context; |
| import android.os.Handler; |
| import android.os.HandlerThread; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.Messenger; |
| import android.os.RemoteException; |
| import android.util.Log; |
| import android.util.SparseArray; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.AsyncChannel; |
| import com.android.internal.util.Protocol; |
| |
| import java.util.concurrent.CountDownLatch; |
| |
| /** |
| * The Network Service Discovery Manager class provides the API to discover services |
| * on a network. As an example, if device A and device B are connected over a Wi-Fi |
| * network, a game registered on device A can be discovered by a game on device |
| * B. Another example use case is an application discovering printers on the network. |
| * |
| * <p> The API currently supports DNS based service discovery and discovery is currently |
| * limited to a local network over Multicast DNS. DNS service discovery is described at |
| * http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt |
| * |
| * <p> The API is asynchronous and responses to requests from an application are on listener |
| * callbacks on a seperate internal thread. |
| * |
| * <p> There are three main operations the API supports - registration, discovery and resolution. |
| * <pre> |
| * Application start |
| * | |
| * | |
| * | onServiceRegistered() |
| * Register any local services / |
| * to be advertised with \ |
| * registerService() onRegistrationFailed() |
| * | |
| * | |
| * discoverServices() |
| * | |
| * Maintain a list to track |
| * discovered services |
| * | |
| * |---------> |
| * | | |
| * | onServiceFound() |
| * | | |
| * | add service to list |
| * | | |
| * |<---------- |
| * | |
| * |---------> |
| * | | |
| * | onServiceLost() |
| * | | |
| * | remove service from list |
| * | | |
| * |<---------- |
| * | |
| * | |
| * | Connect to a service |
| * | from list ? |
| * | |
| * resolveService() |
| * | |
| * onServiceResolved() |
| * | |
| * Establish connection to service |
| * with the host and port information |
| * |
| * </pre> |
| * An application that needs to advertise itself over a network for other applications to |
| * discover it can do so with a call to {@link #registerService}. If Example is a http based |
| * application that can provide HTML data to peer services, it can register a name "Example" |
| * with service type "_http._tcp". A successful registration is notified with a callback to |
| * {@link RegistrationListener#onServiceRegistered} and a failure to register is notified |
| * over {@link RegistrationListener#onRegistrationFailed} |
| * |
| * <p> A peer application looking for http services can initiate a discovery for "_http._tcp" |
| * with a call to {@link #discoverServices}. A service found is notified with a callback |
| * to {@link DiscoveryListener#onServiceFound} and a service lost is notified on |
| * {@link DiscoveryListener#onServiceLost}. |
| * |
| * <p> Once the peer application discovers the "Example" http service, and either needs to read the |
| * attributes of the service or wants to receive data from the "Example" application, it can |
| * initiate a resolve with {@link #resolveService} to resolve the attributes, host, and port |
| * details. A successful resolve is notified on {@link ResolveListener#onServiceResolved} and a |
| * failure is notified on {@link ResolveListener#onResolveFailed}. |
| * |
| * Applications can reserve for a service type at |
| * http://www.iana.org/form/ports-service. Existing services can be found at |
| * http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml |
| * |
| * {@see NsdServiceInfo} |
| */ |
| @SystemService(Context.NSD_SERVICE) |
| public final class NsdManager { |
| private static final String TAG = NsdManager.class.getSimpleName(); |
| private static final boolean DBG = false; |
| |
| /** |
| * Broadcast intent action to indicate whether network service discovery is |
| * enabled or disabled. An extra {@link #EXTRA_NSD_STATE} provides the state |
| * information as int. |
| * |
| * @see #EXTRA_NSD_STATE |
| */ |
| @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) |
| public static final String ACTION_NSD_STATE_CHANGED = "android.net.nsd.STATE_CHANGED"; |
| |
| /** |
| * The lookup key for an int that indicates whether network service discovery is enabled |
| * or disabled. Retrieve it with {@link android.content.Intent#getIntExtra(String,int)}. |
| * |
| * @see #NSD_STATE_DISABLED |
| * @see #NSD_STATE_ENABLED |
| */ |
| public static final String EXTRA_NSD_STATE = "nsd_state"; |
| |
| /** |
| * Network service discovery is disabled |
| * |
| * @see #ACTION_NSD_STATE_CHANGED |
| */ |
| public static final int NSD_STATE_DISABLED = 1; |
| |
| /** |
| * Network service discovery is enabled |
| * |
| * @see #ACTION_NSD_STATE_CHANGED |
| */ |
| public static final int NSD_STATE_ENABLED = 2; |
| |
| private static final int BASE = Protocol.BASE_NSD_MANAGER; |
| |
| /** @hide */ |
| public static final int DISCOVER_SERVICES = BASE + 1; |
| /** @hide */ |
| public static final int DISCOVER_SERVICES_STARTED = BASE + 2; |
| /** @hide */ |
| public static final int DISCOVER_SERVICES_FAILED = BASE + 3; |
| /** @hide */ |
| public static final int SERVICE_FOUND = BASE + 4; |
| /** @hide */ |
| public static final int SERVICE_LOST = BASE + 5; |
| |
| /** @hide */ |
| public static final int STOP_DISCOVERY = BASE + 6; |
| /** @hide */ |
| public static final int STOP_DISCOVERY_FAILED = BASE + 7; |
| /** @hide */ |
| public static final int STOP_DISCOVERY_SUCCEEDED = BASE + 8; |
| |
| /** @hide */ |
| public static final int REGISTER_SERVICE = BASE + 9; |
| /** @hide */ |
| public static final int REGISTER_SERVICE_FAILED = BASE + 10; |
| /** @hide */ |
| public static final int REGISTER_SERVICE_SUCCEEDED = BASE + 11; |
| |
| /** @hide */ |
| public static final int UNREGISTER_SERVICE = BASE + 12; |
| /** @hide */ |
| public static final int UNREGISTER_SERVICE_FAILED = BASE + 13; |
| /** @hide */ |
| public static final int UNREGISTER_SERVICE_SUCCEEDED = BASE + 14; |
| |
| /** @hide */ |
| public static final int RESOLVE_SERVICE = BASE + 18; |
| /** @hide */ |
| public static final int RESOLVE_SERVICE_FAILED = BASE + 19; |
| /** @hide */ |
| public static final int RESOLVE_SERVICE_SUCCEEDED = BASE + 20; |
| |
| /** @hide */ |
| public static final int ENABLE = BASE + 24; |
| /** @hide */ |
| public static final int DISABLE = BASE + 25; |
| |
| /** @hide */ |
| public static final int NATIVE_DAEMON_EVENT = BASE + 26; |
| |
| /** Dns based service discovery protocol */ |
| public static final int PROTOCOL_DNS_SD = 0x0001; |
| |
| private static final SparseArray<String> EVENT_NAMES = new SparseArray<>(); |
| static { |
| EVENT_NAMES.put(DISCOVER_SERVICES, "DISCOVER_SERVICES"); |
| EVENT_NAMES.put(DISCOVER_SERVICES_STARTED, "DISCOVER_SERVICES_STARTED"); |
| EVENT_NAMES.put(DISCOVER_SERVICES_FAILED, "DISCOVER_SERVICES_FAILED"); |
| EVENT_NAMES.put(SERVICE_FOUND, "SERVICE_FOUND"); |
| EVENT_NAMES.put(SERVICE_LOST, "SERVICE_LOST"); |
| EVENT_NAMES.put(STOP_DISCOVERY, "STOP_DISCOVERY"); |
| EVENT_NAMES.put(STOP_DISCOVERY_FAILED, "STOP_DISCOVERY_FAILED"); |
| EVENT_NAMES.put(STOP_DISCOVERY_SUCCEEDED, "STOP_DISCOVERY_SUCCEEDED"); |
| EVENT_NAMES.put(REGISTER_SERVICE, "REGISTER_SERVICE"); |
| EVENT_NAMES.put(REGISTER_SERVICE_FAILED, "REGISTER_SERVICE_FAILED"); |
| EVENT_NAMES.put(REGISTER_SERVICE_SUCCEEDED, "REGISTER_SERVICE_SUCCEEDED"); |
| EVENT_NAMES.put(UNREGISTER_SERVICE, "UNREGISTER_SERVICE"); |
| EVENT_NAMES.put(UNREGISTER_SERVICE_FAILED, "UNREGISTER_SERVICE_FAILED"); |
| EVENT_NAMES.put(UNREGISTER_SERVICE_SUCCEEDED, "UNREGISTER_SERVICE_SUCCEEDED"); |
| EVENT_NAMES.put(RESOLVE_SERVICE, "RESOLVE_SERVICE"); |
| EVENT_NAMES.put(RESOLVE_SERVICE_FAILED, "RESOLVE_SERVICE_FAILED"); |
| EVENT_NAMES.put(RESOLVE_SERVICE_SUCCEEDED, "RESOLVE_SERVICE_SUCCEEDED"); |
| EVENT_NAMES.put(ENABLE, "ENABLE"); |
| EVENT_NAMES.put(DISABLE, "DISABLE"); |
| EVENT_NAMES.put(NATIVE_DAEMON_EVENT, "NATIVE_DAEMON_EVENT"); |
| } |
| |
| /** @hide */ |
| public static String nameOf(int event) { |
| String name = EVENT_NAMES.get(event); |
| if (name == null) { |
| return Integer.toString(event); |
| } |
| return name; |
| } |
| |
| private static final int FIRST_LISTENER_KEY = 1; |
| |
| private final INsdManager mService; |
| private final Context mContext; |
| |
| private int mListenerKey = FIRST_LISTENER_KEY; |
| private final SparseArray mListenerMap = new SparseArray(); |
| private final SparseArray<NsdServiceInfo> mServiceMap = new SparseArray<>(); |
| private final Object mMapLock = new Object(); |
| |
| private final AsyncChannel mAsyncChannel = new AsyncChannel(); |
| private ServiceHandler mHandler; |
| private final CountDownLatch mConnected = new CountDownLatch(1); |
| |
| /** |
| * Create a new Nsd instance. Applications use |
| * {@link android.content.Context#getSystemService Context.getSystemService()} to retrieve |
| * {@link android.content.Context#NSD_SERVICE Context.NSD_SERVICE}. |
| * @param service the Binder interface |
| * @hide - hide this because it takes in a parameter of type INsdManager, which |
| * is a system private class. |
| */ |
| public NsdManager(Context context, INsdManager service) { |
| mService = service; |
| mContext = context; |
| init(); |
| } |
| |
| /** |
| * @hide |
| */ |
| @VisibleForTesting |
| public void disconnect() { |
| mAsyncChannel.disconnect(); |
| mHandler.getLooper().quitSafely(); |
| } |
| |
| /** |
| * Failures are passed with {@link RegistrationListener#onRegistrationFailed}, |
| * {@link RegistrationListener#onUnregistrationFailed}, |
| * {@link DiscoveryListener#onStartDiscoveryFailed}, |
| * {@link DiscoveryListener#onStopDiscoveryFailed} or {@link ResolveListener#onResolveFailed}. |
| * |
| * Indicates that the operation failed due to an internal error. |
| */ |
| public static final int FAILURE_INTERNAL_ERROR = 0; |
| |
| /** |
| * Indicates that the operation failed because it is already active. |
| */ |
| public static final int FAILURE_ALREADY_ACTIVE = 3; |
| |
| /** |
| * Indicates that the operation failed because the maximum outstanding |
| * requests from the applications have reached. |
| */ |
| public static final int FAILURE_MAX_LIMIT = 4; |
| |
| /** Interface for callback invocation for service discovery */ |
| public interface DiscoveryListener { |
| |
| public void onStartDiscoveryFailed(String serviceType, int errorCode); |
| |
| public void onStopDiscoveryFailed(String serviceType, int errorCode); |
| |
| public void onDiscoveryStarted(String serviceType); |
| |
| public void onDiscoveryStopped(String serviceType); |
| |
| public void onServiceFound(NsdServiceInfo serviceInfo); |
| |
| public void onServiceLost(NsdServiceInfo serviceInfo); |
| } |
| |
| /** Interface for callback invocation for service registration */ |
| public interface RegistrationListener { |
| |
| public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode); |
| |
| public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode); |
| |
| public void onServiceRegistered(NsdServiceInfo serviceInfo); |
| |
| public void onServiceUnregistered(NsdServiceInfo serviceInfo); |
| } |
| |
| /** Interface for callback invocation for service resolution */ |
| public interface ResolveListener { |
| |
| public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode); |
| |
| public void onServiceResolved(NsdServiceInfo serviceInfo); |
| } |
| |
| @VisibleForTesting |
| class ServiceHandler extends Handler { |
| ServiceHandler(Looper looper) { |
| super(looper); |
| } |
| |
| @Override |
| public void handleMessage(Message message) { |
| final int what = message.what; |
| final int key = message.arg2; |
| switch (what) { |
| case AsyncChannel.CMD_CHANNEL_HALF_CONNECTED: |
| mAsyncChannel.sendMessage(AsyncChannel.CMD_CHANNEL_FULL_CONNECTION); |
| return; |
| case AsyncChannel.CMD_CHANNEL_FULLY_CONNECTED: |
| mConnected.countDown(); |
| return; |
| case AsyncChannel.CMD_CHANNEL_DISCONNECTED: |
| Log.e(TAG, "Channel lost"); |
| return; |
| default: |
| break; |
| } |
| final Object listener; |
| final NsdServiceInfo ns; |
| synchronized (mMapLock) { |
| listener = mListenerMap.get(key); |
| ns = mServiceMap.get(key); |
| } |
| if (listener == null) { |
| Log.d(TAG, "Stale key " + message.arg2); |
| return; |
| } |
| if (DBG) { |
| Log.d(TAG, "received " + nameOf(what) + " for key " + key + ", service " + ns); |
| } |
| switch (what) { |
| case DISCOVER_SERVICES_STARTED: |
| String s = getNsdServiceInfoType((NsdServiceInfo) message.obj); |
| ((DiscoveryListener) listener).onDiscoveryStarted(s); |
| break; |
| case DISCOVER_SERVICES_FAILED: |
| removeListener(key); |
| ((DiscoveryListener) listener).onStartDiscoveryFailed(getNsdServiceInfoType(ns), |
| message.arg1); |
| break; |
| case SERVICE_FOUND: |
| ((DiscoveryListener) listener).onServiceFound((NsdServiceInfo) message.obj); |
| break; |
| case SERVICE_LOST: |
| ((DiscoveryListener) listener).onServiceLost((NsdServiceInfo) message.obj); |
| break; |
| case STOP_DISCOVERY_FAILED: |
| // TODO: failure to stop discovery should be internal and retried internally, as |
| // the effect for the client is indistinguishable from STOP_DISCOVERY_SUCCEEDED |
| removeListener(key); |
| ((DiscoveryListener) listener).onStopDiscoveryFailed(getNsdServiceInfoType(ns), |
| message.arg1); |
| break; |
| case STOP_DISCOVERY_SUCCEEDED: |
| removeListener(key); |
| ((DiscoveryListener) listener).onDiscoveryStopped(getNsdServiceInfoType(ns)); |
| break; |
| case REGISTER_SERVICE_FAILED: |
| removeListener(key); |
| ((RegistrationListener) listener).onRegistrationFailed(ns, message.arg1); |
| break; |
| case REGISTER_SERVICE_SUCCEEDED: |
| ((RegistrationListener) listener).onServiceRegistered( |
| (NsdServiceInfo) message.obj); |
| break; |
| case UNREGISTER_SERVICE_FAILED: |
| removeListener(key); |
| ((RegistrationListener) listener).onUnregistrationFailed(ns, message.arg1); |
| break; |
| case UNREGISTER_SERVICE_SUCCEEDED: |
| // TODO: do not unregister listener until service is unregistered, or provide |
| // alternative way for unregistering ? |
| removeListener(message.arg2); |
| ((RegistrationListener) listener).onServiceUnregistered(ns); |
| break; |
| case RESOLVE_SERVICE_FAILED: |
| removeListener(key); |
| ((ResolveListener) listener).onResolveFailed(ns, message.arg1); |
| break; |
| case RESOLVE_SERVICE_SUCCEEDED: |
| removeListener(key); |
| ((ResolveListener) listener).onServiceResolved((NsdServiceInfo) message.obj); |
| break; |
| default: |
| Log.d(TAG, "Ignored " + message); |
| break; |
| } |
| } |
| } |
| |
| private int nextListenerKey() { |
| // Ensure mListenerKey >= FIRST_LISTENER_KEY; |
| mListenerKey = Math.max(FIRST_LISTENER_KEY, mListenerKey + 1); |
| return mListenerKey; |
| } |
| |
| // Assert that the listener is not in the map, then add it and returns its key |
| private int putListener(Object listener, NsdServiceInfo s) { |
| checkListener(listener); |
| final int key; |
| synchronized (mMapLock) { |
| int valueIndex = mListenerMap.indexOfValue(listener); |
| checkArgument(valueIndex == -1, "listener already in use"); |
| key = nextListenerKey(); |
| mListenerMap.put(key, listener); |
| mServiceMap.put(key, s); |
| } |
| return key; |
| } |
| |
| private void removeListener(int key) { |
| synchronized (mMapLock) { |
| mListenerMap.remove(key); |
| mServiceMap.remove(key); |
| } |
| } |
| |
| private int getListenerKey(Object listener) { |
| checkListener(listener); |
| synchronized (mMapLock) { |
| int valueIndex = mListenerMap.indexOfValue(listener); |
| checkArgument(valueIndex != -1, "listener not registered"); |
| return mListenerMap.keyAt(valueIndex); |
| } |
| } |
| |
| private static String getNsdServiceInfoType(NsdServiceInfo s) { |
| if (s == null) return "?"; |
| return s.getServiceType(); |
| } |
| |
| /** |
| * Initialize AsyncChannel |
| */ |
| private void init() { |
| final Messenger messenger = getMessenger(); |
| if (messenger == null) { |
| fatal("Failed to obtain service Messenger"); |
| } |
| HandlerThread t = new HandlerThread("NsdManager"); |
| t.start(); |
| mHandler = new ServiceHandler(t.getLooper()); |
| mAsyncChannel.connect(mContext, mHandler, messenger); |
| try { |
| mConnected.await(); |
| } catch (InterruptedException e) { |
| fatal("Interrupted wait at init"); |
| } |
| } |
| |
| private static void fatal(String msg) { |
| Log.e(TAG, msg); |
| throw new RuntimeException(msg); |
| } |
| |
| /** |
| * Register a service to be discovered by other services. |
| * |
| * <p> The function call immediately returns after sending a request to register service |
| * to the framework. The application is notified of a successful registration |
| * through the callback {@link RegistrationListener#onServiceRegistered} or a failure |
| * through {@link RegistrationListener#onRegistrationFailed}. |
| * |
| * <p> The application should call {@link #unregisterService} when the service |
| * registration is no longer required, and/or whenever the application is stopped. |
| * |
| * @param serviceInfo The service being registered |
| * @param protocolType The service discovery protocol |
| * @param listener The listener notifies of a successful registration and is used to |
| * unregister this service through a call on {@link #unregisterService}. Cannot be null. |
| * Cannot be in use for an active service registration. |
| */ |
| public void registerService(NsdServiceInfo serviceInfo, int protocolType, |
| RegistrationListener listener) { |
| checkArgument(serviceInfo.getPort() > 0, "Invalid port number"); |
| checkServiceInfo(serviceInfo); |
| checkProtocol(protocolType); |
| int key = putListener(listener, serviceInfo); |
| mAsyncChannel.sendMessage(REGISTER_SERVICE, 0, key, serviceInfo); |
| } |
| |
| /** |
| * Unregister a service registered through {@link #registerService}. A successful |
| * unregister is notified to the application with a call to |
| * {@link RegistrationListener#onServiceUnregistered}. |
| * |
| * @param listener This should be the listener object that was passed to |
| * {@link #registerService}. It identifies the service that should be unregistered |
| * and notifies of a successful or unsuccessful unregistration via the listener |
| * callbacks. In API versions 20 and above, the listener object may be used for |
| * another service registration once the callback has been called. In API versions <= 19, |
| * there is no entirely reliable way to know when a listener may be re-used, and a new |
| * listener should be created for each service registration request. |
| */ |
| public void unregisterService(RegistrationListener listener) { |
| int id = getListenerKey(listener); |
| mAsyncChannel.sendMessage(UNREGISTER_SERVICE, 0, id); |
| } |
| |
| /** |
| * Initiate service discovery to browse for instances of a service type. Service discovery |
| * consumes network bandwidth and will continue until the application calls |
| * {@link #stopServiceDiscovery}. |
| * |
| * <p> The function call immediately returns after sending a request to start service |
| * discovery to the framework. The application is notified of a success to initiate |
| * discovery through the callback {@link DiscoveryListener#onDiscoveryStarted} or a failure |
| * through {@link DiscoveryListener#onStartDiscoveryFailed}. |
| * |
| * <p> Upon successful start, application is notified when a service is found with |
| * {@link DiscoveryListener#onServiceFound} or when a service is lost with |
| * {@link DiscoveryListener#onServiceLost}. |
| * |
| * <p> Upon failure to start, service discovery is not active and application does |
| * not need to invoke {@link #stopServiceDiscovery} |
| * |
| * <p> The application should call {@link #stopServiceDiscovery} when discovery of this |
| * service type is no longer required, and/or whenever the application is paused or |
| * stopped. |
| * |
| * @param serviceType The service type being discovered. Examples include "_http._tcp" for |
| * http services or "_ipp._tcp" for printers |
| * @param protocolType The service discovery protocol |
| * @param listener The listener notifies of a successful discovery and is used |
| * to stop discovery on this serviceType through a call on {@link #stopServiceDiscovery}. |
| * Cannot be null. Cannot be in use for an active service discovery. |
| */ |
| public void discoverServices(String serviceType, int protocolType, DiscoveryListener listener) { |
| checkStringNotEmpty(serviceType, "Service type cannot be empty"); |
| checkProtocol(protocolType); |
| |
| NsdServiceInfo s = new NsdServiceInfo(); |
| s.setServiceType(serviceType); |
| |
| int key = putListener(listener, s); |
| mAsyncChannel.sendMessage(DISCOVER_SERVICES, 0, key, s); |
| } |
| |
| /** |
| * Stop service discovery initiated with {@link #discoverServices}. An active service |
| * discovery is notified to the application with {@link DiscoveryListener#onDiscoveryStarted} |
| * and it stays active until the application invokes a stop service discovery. A successful |
| * stop is notified to with a call to {@link DiscoveryListener#onDiscoveryStopped}. |
| * |
| * <p> Upon failure to stop service discovery, application is notified through |
| * {@link DiscoveryListener#onStopDiscoveryFailed}. |
| * |
| * @param listener This should be the listener object that was passed to {@link #discoverServices}. |
| * It identifies the discovery that should be stopped and notifies of a successful or |
| * unsuccessful stop. In API versions 20 and above, the listener object may be used for |
| * another service discovery once the callback has been called. In API versions <= 19, |
| * there is no entirely reliable way to know when a listener may be re-used, and a new |
| * listener should be created for each service discovery request. |
| */ |
| public void stopServiceDiscovery(DiscoveryListener listener) { |
| int id = getListenerKey(listener); |
| mAsyncChannel.sendMessage(STOP_DISCOVERY, 0, id); |
| } |
| |
| /** |
| * Resolve a discovered service. An application can resolve a service right before |
| * establishing a connection to fetch the IP and port details on which to setup |
| * the connection. |
| * |
| * @param serviceInfo service to be resolved |
| * @param listener to receive callback upon success or failure. Cannot be null. |
| * Cannot be in use for an active service resolution. |
| */ |
| public void resolveService(NsdServiceInfo serviceInfo, ResolveListener listener) { |
| checkServiceInfo(serviceInfo); |
| int key = putListener(listener, serviceInfo); |
| mAsyncChannel.sendMessage(RESOLVE_SERVICE, 0, key, serviceInfo); |
| } |
| |
| /** Internal use only @hide */ |
| public void setEnabled(boolean enabled) { |
| try { |
| mService.setEnabled(enabled); |
| } catch (RemoteException e) { |
| throw e.rethrowFromSystemServer(); |
| } |
| } |
| |
| /** |
| * Get a reference to NsdService handler. This is used to establish |
| * an AsyncChannel communication with the service |
| * |
| * @return Messenger pointing to the NsdService handler |
| */ |
| private Messenger getMessenger() { |
| try { |
| return mService.getMessenger(); |
| } catch (RemoteException e) { |
| throw e.rethrowFromSystemServer(); |
| } |
| } |
| |
| private static void checkListener(Object listener) { |
| checkNotNull(listener, "listener cannot be null"); |
| } |
| |
| private static void checkProtocol(int protocolType) { |
| checkArgument(protocolType == PROTOCOL_DNS_SD, "Unsupported protocol"); |
| } |
| |
| private static void checkServiceInfo(NsdServiceInfo serviceInfo) { |
| checkNotNull(serviceInfo, "NsdServiceInfo cannot be null"); |
| checkStringNotEmpty(serviceInfo.getServiceName(), "Service name cannot be empty"); |
| checkStringNotEmpty(serviceInfo.getServiceType(), "Service type cannot be empty"); |
| } |
| } |