Java tutorial
/* * Digital Audio Access Protocol (DAAP) * Copyright (C) 2004 Roger Kapsi, info at kapsi dot de * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package de.kapsi.net.daap.bio; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.Socket; import java.net.SocketException; import org.apache.commons.httpclient.Header; import org.apache.commons.httpclient.HttpParser; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import de.kapsi.net.daap.DaapConnection; import de.kapsi.net.daap.DaapRequest; import de.kapsi.net.daap.DaapRequestProcessor; import de.kapsi.net.daap.DaapResponse; import de.kapsi.net.daap.DaapResponseFactory; import de.kapsi.net.daap.DaapSession; import de.kapsi.net.daap.DaapStreamException; import de.kapsi.net.daap.DaapUtil; /** * This class is a cover for an incoming connection and is based * on the classical BIO (Blocking I/O) pattern. A connection * can either be a general DAAP connection or an Audio request. * * @author Roger Kapsi */ public class DaapConnectionBIO extends DaapConnection implements Runnable { private static final Log LOG = LogFactory.getLog(DaapConnectionBIO.class); private static final DaapResponseFactory FACTORY = new DaapResponseFactoryBIO(); private static final DaapRequestProcessor PROCESSOR = new DaapRequestProcessor(FACTORY); private DaapServerBIO server; private Socket socket; private InputStream in; private OutputStream out; private DaapSession session; private boolean connected = false; public DaapConnectionBIO(DaapServerBIO server, Socket socket) throws IOException { super(server); this.server = server; this.socket = socket; in = new BufferedInputStream(socket.getInputStream()); out = socket.getOutputStream(); connected = true; } private boolean read() throws IOException { DaapRequest request = readRequest(); if (!isAudioStream()) { if (isUndef()) { if (request.isSongRequest()) { setConnectionType(DaapConnection.AUDIO); // AudioStreams have a session-id and we must check the id Integer sid = new Integer(request.getSessionId()); if (server.isSessionIdValid(sid) == false) { throw new IOException("Unknown Session-ID: " + sid); } // Get the associated "normal" connection... DaapConnection connection = server.getConnection(sid); if (connection == null) { throw new IOException("No connection associated with this Session-ID: " + sid); } // ...and use its protocolVersion for this Audio Stream // because Audio Streams do not provide the version in // the request header (we could use the User-Agent header // but that breaks compatibility to non iTunes hosts and // they would have to fake their request header. setProtocolVersion(connection.getProtocolVersion()); } else if (request.isServerInfoRequest()) { setConnectionType(DaapConnection.DAAP); setProtocolVersion(DaapUtil.getProtocolVersion(request)); } else { // disconnect as the first request must be // either a song or server-info request! throw new IOException("Illegal first request: " + request); } if (!DaapUtil.isSupportedProtocolVersion(getProtocolVersion())) { throw new IOException("Unsupported Protocol Version: " + getProtocolVersion()); } // add connection to the connection pool if (!server.addConnection(this)) { throw new IOException("Server refused this connection"); } } DaapResponse response = PROCESSOR.process(request); if (response != null) { writer.add(response); } return true; } throw new IOException("Cannot read requests from audio stream"); } public void run() { try { do { read(); } while (connected && write()); } catch (DaapStreamException err) { // LOG.info(err); // This exception can be ignored as it's thrown // whenever the user presses the pause, fast-forward // and so on button } catch (SocketException err) { // LOG.info(err); // This exception can be ignored as it's thrown // whenever the user disconnects... } catch (IOException err) { LOG.error(err); } finally { close(); } } public synchronized void update() throws IOException { if (isDaapConnection()) { DaapSession session = getSession(false); // Do not trigger new updates if an update for this connection // is already running, it will autumatically update to the // lates revision of the library! if (session != null && !session.hasAttribute("UPDATE_LOCK")) { Integer sessionId = session.getSessionId(); Integer delta = (Integer) session.getAttribute("DELTA"); Integer revisionNumber = (Integer) session.getAttribute("REVISION-NUMBER"); if (delta != null && revisionNumber != null) { DaapRequest request = new DaapRequest(this, sessionId.intValue(), revisionNumber.intValue(), delta.intValue()); DaapResponse response = PROCESSOR.process(request); if (response != null) response.write(); } } } } void disconnect() { connected = false; close(); } public void close() { super.close(); try { if (in != null) in.close(); } catch (IOException err) { LOG.error("Error while closing connection", err); } try { if (out != null) out.close(); } catch (IOException err) { LOG.error("Error while closing connection", err); } try { if (socket != null) socket.close(); } catch (IOException err) { LOG.error("Error while closing connection", err); } if (connected) server.removeConnection(this); } public InputStream getInputStream() { return in; } public OutputStream getOutputStream() { return out; } private DaapRequest readRequest() throws IOException { String line = null; do { line = HttpParser.readLine(in); } while (line != null && line.length() == 0); if (line == null) { throw new IOException("Request is null: " + this); } DaapRequest request = new DaapRequest(this, line); Header[] headers = HttpParser.parseHeaders(in); request.addHeaders(headers); return request; } public String toString() { StringBuffer buffer = new StringBuffer("DaapConnection ["); buffer.append("Host: ").append(socket.getInetAddress()).append(":").append(socket.getPort()); buffer.append(", audioStream: ").append(isAudioStream()); buffer.append(", hasSession: ").append(getSession(false) != null); return buffer.append("]").toString(); } }