Java tutorial
/* * (C) Copyright 2013 Kurento (http://kurento.org/) * * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Lesser General Public License * (LGPL) version 2.1 which accompanies this distribution, and is available at * http://www.gnu.org/licenses/lgpl-2.1.html * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * */ package com.kurento.kmf.content.internal.base; import java.util.concurrent.Future; import javax.servlet.AsyncContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.beans.factory.annotation.Autowired; import com.kurento.kmf.common.exception.Assert; import com.kurento.kmf.common.exception.KurentoMediaFrameworkException; import com.kurento.kmf.common.exception.internal.ExceptionUtils; import com.kurento.kmf.common.exception.internal.ServletUtils; import com.kurento.kmf.content.ContentHandler; import com.kurento.kmf.content.ContentSession; import com.kurento.kmf.content.HttpContentSession; import com.kurento.kmf.content.internal.ContentSessionManager; import com.kurento.kmf.content.internal.StreamingProxy; import com.kurento.kmf.content.internal.StreamingProxyListener; import com.kurento.kmf.content.jsonrpc.JsonRpcResponse; import com.kurento.kmf.media.HttpEndpoint; import com.kurento.kmf.media.events.ErrorEvent; import com.kurento.kmf.media.events.MediaEventListener; import com.kurento.kmf.media.events.MediaSessionStartedEvent; import com.kurento.kmf.media.events.MediaSessionTerminatedEvent; import com.kurento.kmf.repository.HttpSessionErrorEvent; import com.kurento.kmf.repository.HttpSessionStartedEvent; import com.kurento.kmf.repository.HttpSessionTerminatedEvent; import com.kurento.kmf.repository.RepositoryHttpEndpoint; import com.kurento.kmf.repository.RepositoryHttpEventListener; import com.kurento.kmf.repository.RepositoryItem; /** * * Abstract definition for HTTP based content request. * * @author Luis Lpez (llopez@gsyc.es) * @version 1.0.0 */ public abstract class AbstractHttpContentSession extends AbstractContentSession implements HttpContentSession { @Autowired private StreamingProxy proxy; protected boolean useControlProtocol; protected boolean redirect; protected volatile Future<?> tunnellingProxyFuture; private RepositoryHttpEndpoint repositoryHttpEndpoint; public AbstractHttpContentSession(ContentHandler<? extends ContentSession> handler, ContentSessionManager manager, AsyncContext asyncContext, String contentId, boolean redirect, boolean useControlProtocol) { super(handler, manager, asyncContext, contentId); this.useControlProtocol = useControlProtocol; this.redirect = redirect; if (!useControlProtocol) { goToState(STATE.HANDLING, "Cannot go to STATE.HANDLING from state " + getState() + ". This condition should never happen", 1); // TODO } } protected abstract RepositoryHttpEndpoint createRepositoryHttpEndpoint(RepositoryItem repositoryItem); public void start(HttpEndpoint httpEndpoint) { try { releaseOnTerminate(httpEndpoint); Assert.notNull(httpEndpoint, "Illegal null httpEndpoint provided", 10028); goToState(STATE.STARTING, "Cannot start HttpEndpoint in state " + getState() + ". This is probably due to an explicit session termination comming from another thread", 1); // TODO getLogger().info( "Activating media for " + this.getClass().getSimpleName() + " with httpEndpoint provided "); activateMedia(httpEndpoint, null); } catch (KurentoMediaFrameworkException ke) { internalTerminateWithError(null, ke.getCode(), ke.getMessage(), null); throw ke; } catch (Throwable t) { KurentoMediaFrameworkException kmfe = new KurentoMediaFrameworkException(t.getMessage(), t, 20029); internalTerminateWithError(null, kmfe.getCode(), kmfe.getMessage(), null); throw kmfe; } } @Override public void start(RepositoryItem repositoryItem) { try { Assert.notNull(repositoryItem, "Illegal null repositoryItem provided", 10027); goToState(STATE.STARTING, "Cannot start HttpPlayerSession in state " + getState() + ". This is probably due to an explicit session termination comming from another thread", 1); // TODO getLogger().info("Activating media for " + this.getClass().getSimpleName() + " with repositoryItemId " + repositoryItem.getId()); repositoryHttpEndpoint = createRepositoryHttpEndpoint(repositoryItem); activateMedia(repositoryHttpEndpoint); } catch (KurentoMediaFrameworkException ke) { internalTerminateWithError(null, ke.getCode(), ke.getMessage(), null); throw ke; } catch (Throwable t) { KurentoMediaFrameworkException kmfe = new KurentoMediaFrameworkException(t.getMessage(), t, 20029); internalTerminateWithError(null, kmfe.getCode(), kmfe.getMessage(), null); throw kmfe; } } /* * This is an utility method designed for minimizing code replication. For * it to work, one and only one of the two parameters must be null; */ protected void activateMedia(HttpEndpoint httpEndpoint, final Runnable runOnContentStart) { Assert.isTrue(httpEndpoint != null, "Internal error. Cannot activate null HttpEndpoint reference", 1); // TODO // Manage fatal errors occurring in the pipeline httpEndpoint.getMediaPipeline().addErrorListener(new MediaEventListener<ErrorEvent>() { @Override public void onEvent(ErrorEvent error) { getLogger().error(error.getDescription()); // TODO: // improve // message internalTerminateWithError(null, error.getErrorCode(), error.getDescription(), null); } }); // Generate appropriate actions when content is started httpEndpoint.addMediaSessionStartedListener(new MediaEventListener<MediaSessionStartedEvent>() { @Override public void onEvent(MediaSessionStartedEvent event) { callOnContentStartedOnHanlder(); getLogger().info("Received event with type " + event.getType()); if (runOnContentStart != null) { runOnContentStart.run(); } } }); // Manage end of media session httpEndpoint.addMediaSessionTerminatedListener(new MediaEventListener<MediaSessionTerminatedEvent>() { @Override public void onEvent(MediaSessionTerminatedEvent event) { internalTerminateWithoutError(null, 1, "TODO", null);// TODO } }); // Generate appropriate actions when media session is terminated String answerUrl = httpEndpoint.getUrl(); getLogger().info("HttpEndpoint.getUrl = " + answerUrl); Assert.notNull(answerUrl, "Received null url from HttpEndpoint", 20012); Assert.isTrue(answerUrl.length() > 0, "Received invalid empty url from media server", 20012); goToState(STATE.ACTIVE, "Cannot start session in sate " + getState() + ". This is probably due to an explicit termination of the session from a different threaad", 1); if (useControlProtocol) { answerActivateMediaRequest4JsonControlProtocolConfiguration(answerUrl); } else if (redirect) { answerActivateMediaRequest4SimpleHttpConfigurationWithRedirect(answerUrl); } else { answerActivateMediaRequest4SimpleHttpConfigurationWithTunnel(answerUrl); } } protected void activateMedia(RepositoryHttpEndpoint repositoryHttpEndpoint) { // Manage fatal errors occurring in the pipeline repositoryHttpEndpoint.addSessionErrorListener(new RepositoryHttpEventListener<HttpSessionErrorEvent>() { @Override public void onEvent(HttpSessionErrorEvent event) { getLogger().error(event.getDescription()); // TODO: internalTerminateWithError(null, 1, // TODO event.getDescription(), null); } }); // Generate appropriate actions when content is started // TODO: addMediaSessionStartListener (symmetry) repositoryHttpEndpoint .addSessionStartedListener(new RepositoryHttpEventListener<HttpSessionStartedEvent>() { @Override public void onEvent(HttpSessionStartedEvent event) { callOnContentStartedOnHanlder(); getLogger().info("Received event with type " + event.getClass().getSimpleName()); } }); repositoryHttpEndpoint .addSessionTerminatedListener(new RepositoryHttpEventListener<HttpSessionTerminatedEvent>() { @Override public void onEvent(HttpSessionTerminatedEvent event) { getLogger().info("Received event with type " + event.getClass().getSimpleName()); internalTerminateWithoutError(null, 1, "MediaServer MediaSessionTerminated", null); // TODO } }); String answerUrl = repositoryHttpEndpoint.getURL(); getLogger().info("RepoItemHttpElement.getUrl = " + answerUrl); Assert.notNull(answerUrl, "Received null url from RepoItemHttpElement", 20012); Assert.isTrue(answerUrl.length() > 0, "Received invalid empty url from RepoItemHttpElement", 20012); goToState(STATE.ACTIVE, "Cannot start session in sate " + getState() + ". This is probably due to an explicit termination of the session from a different threaad", 1); if (useControlProtocol) { answerActivateMediaRequest4JsonControlProtocolConfiguration(answerUrl); } else if (redirect) { answerActivateMediaRequest4SimpleHttpConfigurationWithRedirect(answerUrl); } else { answerActivateMediaRequest4SimpleHttpConfigurationWithDispatch(repositoryHttpEndpoint.getDispatchURL()); } } /** * Provide an HTTP response, depending of which redirect strategy is used: * it could a redirect (HTTP 307, Temporary Redirect), or a tunneled * response using the Streaming Proxy. * * @param url * Content URL * @throws ContentException * Exception in the media server */ private void answerActivateMediaRequest4SimpleHttpConfigurationWithRedirect(String url) { try { HttpServletResponse response = (HttpServletResponse) initialAsyncCtx.getResponse(); getLogger().info("Sending redirect to " + url); response.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT); response.setHeader("Location", url); } catch (Throwable t) { throw new KurentoMediaFrameworkException(t.getMessage(), t, 20013); } finally { initialAsyncCtx.complete(); initialAsyncCtx = null; } } private void answerActivateMediaRequest4SimpleHttpConfigurationWithTunnel(String url) { try { HttpServletResponse response = (HttpServletResponse) initialAsyncCtx.getResponse(); final HttpServletRequest request = (HttpServletRequest) initialAsyncCtx.getRequest(); getLogger().info("Activating tunneling proxy to " + url); tunnellingProxyFuture = proxy.tunnelTransaction(request, response, url, new StreamingProxyListener() { @Override public void onProxySuccess() { tunnellingProxyFuture = null; // Parameters no matter, no answer will be sent // given that we are already in ACTIVE state terminate(0, ""); request.getAsyncContext().complete(); } @Override public void onProxyError(String message, int errorCode) { tunnellingProxyFuture = null; // Parameters no matter, no answer will be sent // given that we are already in ACTIVE state terminate(errorCode, message); request.getAsyncContext().complete(); } }); } catch (Throwable t) { throw new KurentoMediaFrameworkException(t.getMessage(), t, 20013); } finally { initialAsyncCtx = null; } } private void answerActivateMediaRequest4SimpleHttpConfigurationWithDispatch(String path) { try { initialAsyncCtx.dispatch(path); } catch (Throwable t) { throw new KurentoMediaFrameworkException(t.getMessage(), t, 20013); } finally { initialAsyncCtx = null; } } /** * Provide an HTTP response, when a JSON signaling protocol strategy is * used. * * @param url * Content URL * @throws ContentException * Exception in the media server */ private void answerActivateMediaRequest4JsonControlProtocolConfiguration(String url) { protocolManager.sendJsonAnswer(initialAsyncCtx, JsonRpcResponse.newStartUrlResponse(url, sessionId, initialJsonRequest.getId())); initialAsyncCtx = null; initialJsonRequest = null; } /** * Control protocol accessor (getter). * * @return Control protocol strategy */ @Override public boolean useControlProtocol() { return useControlProtocol; } @Override protected void sendErrorAnswerOnInitialContext(int code, String description) { if (useControlProtocol) { super.sendErrorAnswerOnInitialContext(code, description); } else { try { ServletUtils.sendHttpError((HttpServletRequest) initialAsyncCtx.getRequest(), (HttpServletResponse) initialAsyncCtx.getResponse(), ExceptionUtils.getHttpErrorCode(code), description); } catch (ServletException e) { getLogger().error(e.getMessage(), e); throw new KurentoMediaFrameworkException(e, 20026); } } } @Override protected void sendRejectOnInitialContext(int code, String description) { if (useControlProtocol) { super.sendRejectOnInitialContext(code, description); } else { try { ServletUtils.sendHttpError((HttpServletRequest) initialAsyncCtx.getRequest(), (HttpServletResponse) initialAsyncCtx.getResponse(), ExceptionUtils.getHttpErrorCode(code), description); } catch (ServletException e) { getLogger().error(e.getMessage(), e); throw new KurentoMediaFrameworkException(e, 20026); } } } /** * Release Streaming proxy. */ @Override protected synchronized void destroy() { super.destroy(); if (repositoryHttpEndpoint != null) { repositoryHttpEndpoint.stop(); repositoryHttpEndpoint = null; } Future<?> localTunnelingProxyFuture = tunnellingProxyFuture; if (localTunnelingProxyFuture != null) { localTunnelingProxyFuture.cancel(true); tunnellingProxyFuture = null; } } }