From 85557be7a45f85c4f98d92ad4e91e353d604d113 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Sun, 29 Jul 2012 01:35:25 +0200
Subject: [PATCH] Add servlet that lets the user download a track.

---
 .../demoscenemusic/core/DownloadServlet.java       | 97 ++++++++++++++++++++++
 src/main/webapp/WEB-INF/web.xml.template           | 10 +++
 2 files changed, 107 insertions(+)
 create mode 100644 src/main/java/net/pterodactylus/demoscenemusic/core/DownloadServlet.java

diff --git a/src/main/java/net/pterodactylus/demoscenemusic/core/DownloadServlet.java b/src/main/java/net/pterodactylus/demoscenemusic/core/DownloadServlet.java
new file mode 100644
index 0000000..15f3db6
--- /dev/null
+++ b/src/main/java/net/pterodactylus/demoscenemusic/core/DownloadServlet.java
@@ -0,0 +1,97 @@
+/*
+ * DemosceneMusic - DownloadServlet.java - Copyright © 2012 David Roden
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.demoscenemusic.core;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import net.pterodactylus.demoscenemusic.data.Artist;
+import net.pterodactylus.demoscenemusic.data.Track;
+import net.pterodactylus.demoscenemusic.data.TrackDerivative;
+import net.pterodactylus.demoscenemusic.utils.AudioCodecs;
+import net.pterodactylus.util.database.DatabaseException;
+import net.pterodactylus.util.io.Closer;
+import net.pterodactylus.util.io.StreamCopier;
+
+/**
+ * {@link HttpServlet} that lets the user download a track.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class DownloadServlet extends HttpServlet {
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
+		Core core = (Core) getServletContext().getAttribute("core");
+		try {
+			String derivativeId = httpServletRequest.getParameter("id");
+			TrackDerivative derivative = core.getDataManager().getTrackDerivativeById(derivativeId);
+			Track track = core.getDataManager().getTrackByDerivativeId(derivativeId);
+			/* TODO - checking. */
+
+			/* create name of file. */
+			StringBuilder filename = new StringBuilder();
+			for (Artist artist : track.getArtists()) {
+				if (filename.length() > 0) {
+					filename.append(" & ");
+				}
+				filename.append(artist.getName());
+			}
+			filename.append(" - ");
+			filename.append(track.getName());
+			if (track.getRemix() != null) {
+				filename.append(" (");
+				filename.append(track.getRemix());
+				filename.append(")");
+			}
+			filename.append('.').append(derivative.getProperties().get("file/extension"));
+
+			/* prepare response. */
+			File file = core.getDataDirectory().getFile(derivativeId);
+			httpServletResponse.addHeader("Content-Disposition", "attachment; filename=" + filename.toString());
+			httpServletResponse.setContentType(AudioCodecs.codecDescriptions.get(derivative.getProperties().get("audio/codec")).mimeType);
+			httpServletResponse.setContentLength((int) file.length());
+			httpServletResponse.setStatus(HttpServletResponse.SC_OK);
+
+			/* send file. */
+			OutputStream servletOutputStream = httpServletResponse.getOutputStream();
+			InputStream fileInputStream = new FileInputStream(file);
+			try {
+				StreamCopier.copy(fileInputStream, servletOutputStream);
+			} finally {
+				Closer.close(fileInputStream);
+				Closer.close(servletOutputStream);
+			}
+
+		} catch (DatabaseException de1) {
+			throw new RuntimeException("Could not load derivative.", de1);
+		}
+	}
+
+}
diff --git a/src/main/webapp/WEB-INF/web.xml.template b/src/main/webapp/WEB-INF/web.xml.template
index 573d063..4b5bd70 100644
--- a/src/main/webapp/WEB-INF/web.xml.template
+++ b/src/main/webapp/WEB-INF/web.xml.template
@@ -93,12 +93,22 @@
 		<load-on-startup>0</load-on-startup>
 	</servlet>
 
+	<servlet>
+		<servlet-name>DownloadServlet</servlet-name>
+		<servlet-class>net.pterodactylus.demoscenemusic.core.DownloadServlet</servlet-class>
+	</servlet>
+
 	<servlet-mapping>
 		<servlet-name>StaticServlet</servlet-name>
 		<url-pattern>/static/*</url-pattern>
 	</servlet-mapping>
 
 	<servlet-mapping>
+		<servlet-name>DownloadServlet</servlet-name>
+		<url-pattern>/download</url-pattern>
+	</servlet-mapping>
+
+	<servlet-mapping>
 		<servlet-name>TemplateServlet</servlet-name>
 		<url-pattern>/*</url-pattern>
 	</servlet-mapping>
-- 
2.7.4