chore: introduce RemoteResource<T> interface

src/main/java/org/terasology/launcher/game/GameManager.java

@@ -10,18 +10,17 @@
 import org.slf4j.LoggerFactory;
 import org.terasology.launcher.model.GameIdentifier;
 import org.terasology.launcher.model.GameRelease;
+import org.terasology.launcher.remote.DownloadException;
+import org.terasology.launcher.remote.DownloadUtils;
+import org.terasology.launcher.remote.RemoteResource;
 import org.terasology.launcher.tasks.ProgressListener;
-import org.terasology.launcher.util.DownloadException;
-import org.terasology.launcher.util.DownloadUtils;
 import org.terasology.launcher.util.FileUtils;
 
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.StandardCopyOption;
 import java.util.Comparator;
 import java.util.Objects;
 import java.util.Set;
@@ -52,25 +51,14 @@ public GameManager(Path cacheDirectory, Path installDirectory) {
         scanInstallationDir();
     }
 
-    /**
-     * Derive the file name for the downloaded ZIP package from the game release.
-     */
-    private String getFileNameFor(GameRelease release) {
-        GameIdentifier id = release.getId();
-        String profileString = id.getProfile().toString().toLowerCase();
-        String versionString = id.getDisplayVersion();
-        String buildString = id.getBuild().toString().toLowerCase();
-        return "terasology-" + profileString + "-" + versionString + "-" + buildString + ".zip";
-    }
-
     /**
      * Installs the given release to the local file system.
      *
      * @param release  the game release to be installed
      * @param listener the object which is to be informed about task progress
      */
     public void install(GameRelease release, ProgressListener listener) throws IOException, DownloadException, InterruptedException {
-        final Path cachedZip = cacheDirectory.resolve(getFileNameFor(release));
+        final Path cachedZip = cacheDirectory.resolve(release.getFilename());
 
         // TODO: Properly validate cache and handle exceptions
         if (Files.notExists(cachedZip)) {
@@ -85,30 +73,18 @@ public void install(GameRelease release, ProgressListener listener) throws IOExc
         }
     }
 
+    /**
+     * @deprecated Use {@link DownloadUtils#download(RemoteResource, Path, ProgressListener)} instead.
+     */
+    @Deprecated
     private void download(GameRelease release, Path targetLocation, ProgressListener listener)
             throws DownloadException, IOException, InterruptedException {
-        final URL downloadUrl = release.getUrl();
-
-        final long contentLength = DownloadUtils.getContentLength(downloadUrl);
-        final long availableSpace = targetLocation.getParent().toFile().getUsableSpace();
-
-        if (availableSpace >= contentLength) {
-            final Path cacheZipPart = targetLocation.resolveSibling(targetLocation.getFileName().toString() + ".part");
-            Files.deleteIfExists(cacheZipPart);
-            try {
-                DownloadUtils.downloadToFile(downloadUrl, cacheZipPart, listener).get();
-            } catch (ExecutionException e) {
-                throw new DownloadException("Exception while downloading " + downloadUrl, e.getCause());
-            }
-
-            if (!listener.isCancelled()) {
-                Files.move(cacheZipPart, targetLocation, StandardCopyOption.ATOMIC_MOVE);
-            }
-        } else {
-            throw new DownloadException("Insufficient space for downloading package");
+        DownloadUtils downloader = new DownloadUtils();
+        try {
+            downloader.download(release, targetLocation, listener).get();
+        } catch (ExecutionException e) {
+            throw new DownloadException("Download failed.", e.getCause());
         }
-
-        logger.info("Finished downloading package: {}", release.getId());
     }
 
     /**

src/main/java/org/terasology/launcher/model/GameRelease.java

@@ -3,6 +3,8 @@
 
 package org.terasology.launcher.model;
 
+import org.terasology.launcher.remote.RemoteResource;
+
 import java.net.URL;
 import java.util.Date;
 import java.util.Objects;
@@ -17,7 +19,7 @@
  *     <li>TODO: define what the <b>artifact</b> is, and what requirements/restrictions there are</li>
  * </ul>
  */
-public class GameRelease {
+public class GameRelease implements RemoteResource<GameIdentifier> {
     final GameIdentifier id;
     final ReleaseMetadata releaseMetadata;
     final URL url;
@@ -36,6 +38,19 @@ public URL getUrl() {
         return url;
     }
 
+    @Override
+    public String getFilename() {
+        String profileString = id.getProfile().toString().toLowerCase();
+        String versionString = id.getDisplayVersion();
+        String buildString = id.getBuild().toString().toLowerCase();
+        return "terasology-" + profileString + "-" + versionString + "-" + buildString + ".zip";
+    }
+
+    @Override
+    public GameIdentifier getInfo() {
+        return id;
+    }
+
     /**
      * The changelog associated with the game release
      */

src/main/java/org/terasology/launcher/util/DownloadException.java → src/main/java/org/terasology/launcher/remote/DownloadException.java

@@ -1,7 +1,7 @@
-// Copyright 2021 The Terasology Foundation
+// Copyright 2023 The Terasology Foundation
 // SPDX-License-Identifier: Apache-2.0
 
-package org.terasology.launcher.util;
+package org.terasology.launcher.remote;
 
 
 public final class DownloadException extends RuntimeException {

src/main/java/org/terasology/launcher/util/DownloadUtils.java → src/main/java/org/terasology/launcher/remote/DownloadUtils.java

@@ -1,37 +1,81 @@
-// Copyright 2021 The Terasology Foundation
+// Copyright 2023 The Terasology Foundation
 // SPDX-License-Identifier: Apache-2.0
 
-package org.terasology.launcher.util;
+package org.terasology.launcher.remote;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.terasology.launcher.tasks.ProgressListener;
 
+import javax.net.ssl.HttpsURLConnection;
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.net.HttpURLConnection;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.time.Duration;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 
 public final class DownloadUtils {
 
     private static final Logger logger = LoggerFactory.getLogger(DownloadUtils.class);
 
-    private static final Duration CONNECT_TIMEOUT = Duration.ofSeconds(30);
-    private static final Duration READ_TIMEOUT = Duration.ofMinutes(5);
+    private static final Duration DEFAULT_CONNECT_TIMEOUT = Duration.ofSeconds(30);
+    private static final Duration DEFAULT_READ_TIMEOUT = Duration.ofMinutes(5);
 
-    private DownloadUtils() {
+    private final Duration connectTimeout; //TODO: use instead of default
+    private final Duration readTimeout; //TODO: use instead of default
+
+    public DownloadUtils() {
+        this(DEFAULT_CONNECT_TIMEOUT, DEFAULT_READ_TIMEOUT);
+    }
+
+    public DownloadUtils(Duration connectTimeout, Duration readTimeout) {
+        this.connectTimeout = connectTimeout;
+        this.readTimeout = readTimeout;
+    }
+
+    public <T> CompletableFuture<Path> download(RemoteResource<T> resource, Path path, ProgressListener listener)
+            throws DownloadException, IOException, InterruptedException {
+        final URL downloadUrl = resource.getUrl();
+
+        final long contentLength = DownloadUtils.getContentLength(downloadUrl);
+        final long availableSpace = path.getParent().toFile().getUsableSpace();
+
+        if (availableSpace >= contentLength) {
+            final Path cacheZipPart = path.resolveSibling(path.getFileName().toString() + ".part");
+            Files.deleteIfExists(cacheZipPart);
+            try {
+                DownloadUtils.downloadToFile(downloadUrl, cacheZipPart, listener).get();
+            } catch (ExecutionException e) {
+                throw new DownloadException("Exception while downloading " + downloadUrl, e.getCause());
+            }
+
+            if (!listener.isCancelled()) {
+                Files.move(cacheZipPart, path, StandardCopyOption.ATOMIC_MOVE);
+            }
+        } else {
+            throw new DownloadException("Insufficient space for downloading package");
+        }
+
+        logger.info("Finished downloading package: {}", resource.getInfo());
+
+
+        return CompletableFuture.supplyAsync(() -> path);
     }
 
+    /**
+     * @deprecated Use {@link #download(RemoteResource, Path, ProgressListener)} instead;
+     */
+    @Deprecated
     public static CompletableFuture<Void> downloadToFile(URL downloadURL, Path file, ProgressListener listener) throws DownloadException {
         listener.update(0);
 
@@ -62,30 +106,27 @@ public static CompletableFuture<Void> downloadToFile(URL downloadURL, Path file,
         });
     }
 
+    @Deprecated
     public static long getContentLength(URL downloadURL) throws DownloadException {
-        HttpURLConnection connection = null;
+        HttpsURLConnection connection = null;
         try {
-            connection = (HttpURLConnection) downloadURL.openConnection();
+            connection = (HttpsURLConnection) downloadURL.openConnection();
             connection.setRequestMethod("HEAD");
             return connection.getContentLengthLong();
         } catch (IOException e) {
             throw new DownloadException("Could not send HEAD request to HTTP-URL! URL=" + downloadURL, e);
-        } finally {
-            if (connection != null) {
-                connection.disconnect();
-            }
         }
     }
 
     private static CompletableFuture<HttpResponse<InputStream>> getConnectedDownloadConnection(URL downloadURL) throws DownloadException {
         var client = HttpClient.newBuilder()
                 .followRedirects(HttpClient.Redirect.NORMAL)
-                .connectTimeout(CONNECT_TIMEOUT)
+                .connectTimeout(DEFAULT_CONNECT_TIMEOUT)
                 .build();
 
         HttpRequest request;
         try {
-            request = HttpRequest.newBuilder(downloadURL.toURI()).timeout(READ_TIMEOUT).build();
+            request = HttpRequest.newBuilder(downloadURL.toURI()).timeout(DEFAULT_READ_TIMEOUT).build();
         } catch (URISyntaxException e) {
             throw new DownloadException("Error in URL: " + downloadURL, e);
         }

src/main/java/org/terasology/launcher/remote/RemoteResource.java

@@ -0,0 +1,17 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.remote;
+
+import java.net.URL;
+
+public interface RemoteResource<T> {
+
+    URL getUrl();
+
+    String getFilename();
+
+    T getInfo();
+
+    //TODO: String getChecksum();
+}

src/main/java/org/terasology/launcher/tasks/DownloadTask.java

@@ -8,7 +8,7 @@
 import org.slf4j.LoggerFactory;
 import org.terasology.launcher.game.GameManager;
 import org.terasology.launcher.model.GameRelease;
-import org.terasology.launcher.util.DownloadException;
+import org.terasology.launcher.remote.DownloadException;
 
 import java.io.IOException;