Avoid the github API for better accessibility.

This also allowed me to get rid of gson.

pom.xml

@@ -70,10 +70,5 @@
 	</repositories>
 
 	<dependencies>
-		<dependency>
-			<groupId>com.google.code.gson</groupId>
-			<artifactId>gson</artifactId>
-			<version>2.8.6</version>
-		</dependency>
 	</dependencies>
 </project>

src/io/cubyz/Main.java

@@ -1,24 +1,25 @@
 package io.cubyz;
 
+import java.net.URL;
+
 import javax.swing.JOptionPane;
 
 import io.cubyz.github.GitHubConnection;
-import io.cubyz.github.GithubRelease;
 import io.cubyz.ui.MainGUI;
 
 public class Main {
-	public static final String versionString = "0.2.1";
+	public static final int RELEASE_NUMBER = 1;
 	public static void main(String[] args) {
 		// Check if a new version is available:
 		try {
-			GithubRelease newest = GitHubConnection.downloadReleaseData("https://api.github.com/repos/PixelGuys/Cubyz-Launcher/releases?per_page=1")[0];
-			if(!newest.version.equals(versionString)) {
-				// Prompt the user to update:
-				JOptionPane.showInternalMessageDialog(null, "A new update of launcher is available.", "information", JOptionPane.INFORMATION_MESSAGE);
-			}
-		} catch(Exception e) {
-			e.printStackTrace();
-		}
-		new MainGUI(GitHubConnection.downloadReleaseData("https://api.github.com/repos/PixelGuys/Cubyz/releases?per_page=100"));
+			String link = "https://github.com/PixelGuys/Cubyz-Launcher/releases/download/R"+(RELEASE_NUMBER + 1)+"/cubyz-launcher.jar";
+			URL url = new URL(link);
+			url.openStream().close();
+			// If no exception was thrown, there is a new launcher version.
+			// Prompt the user to update:
+			JOptionPane.showInternalMessageDialog(null, "A new update of launcher is available.", "information", JOptionPane.INFORMATION_MESSAGE);
+		} catch(Exception e) {}
+		GitHubConnection.downloadReleaseData();
+		new MainGUI();
 	}
 }

src/io/cubyz/dependency/DependencyManager.java

@@ -17,7 +17,7 @@
 import org.w3c.dom.NodeList;
 
 import io.cubyz.OSInfo;
-import io.cubyz.github.GithubAsset;
+import io.cubyz.util.DownloadAndFileManager;
 import io.cubyz.util.SimpleMap;
 
 /**
@@ -55,15 +55,15 @@ public Dependency(String groupId, String artifactId, String version, String clas
 		}
 	}
 	private static MyNode root;
-	public static ArrayList<String> fetchDependencies(GithubAsset pom, String absolutePath) {
+	public static ArrayList<String> fetchDependencies(String pomURL, String absolutePath, File pom) {
 		if(!absolutePath.endsWith("/")) absolutePath += "/";
 		ArrayList<String> paths = new ArrayList<>(); // Paths to dependency location on disk.
 		try {
 			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
 			factory.setIgnoringComments(true);
 			factory.setIgnoringElementContentWhitespace(true);
 			DocumentBuilder builder = factory.newDocumentBuilder();
-			Document doc = builder.parse(pom.downloadToStream());
+			Document doc = builder.parse(DownloadAndFileManager.downloadToStream(pomURL, pom));
 			parse(doc);
 			insertVariables();
 			ArrayList<Dependency> dependencies = getDependencyList();

src/io/cubyz/github/GitHubConnection.java

@@ -1,79 +1,148 @@
 package io.cubyz.github;
-import java.io.ByteArrayOutputStream;
+
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
-import java.net.MalformedURLException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.lang.ProcessBuilder.Redirect;
 import java.net.URL;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
 import java.util.ArrayList;
 
-import javax.net.ssl.HttpsURLConnection;
+import javax.swing.JOptionPane;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
+import io.cubyz.OSInfo;
+import io.cubyz.dependency.DependencyManager;
+import io.cubyz.util.DownloadAndFileManager;
 
 /**
  * Connect to github and get an array of all existing releases.
  */
 public class GitHubConnection {
 	/**
-	 * Function to remove comments(as [[comment]]) from the description and to ensure the result isn't null.
+	 * Downloads the general information about every available release.
+	 * Creates new folders for the results.
 	 */
-	private static String getDescription(JsonElement e) {
-		if(e.isJsonNull()) return "";
-		return e.getAsString().replaceAll("\\[\\[(.|\\R)*\\]\\]", "").replace("\n", "<br>");
+	public static void downloadReleaseData() {
+		try {
+			for(int i = 1; ; i++) {
+				// If the folder already exists, there is no need to try and download the data again:
+				File file = new File(System.getProperty("user.home") + "/.cubyz/" + "R" + i + "/release_info");
+				if(file.exists()) continue;
+
+				// Tests if the version `i` is available if so reads the file, otherwise throws an Exception.
+				String link = "https://github.com/PixelGuys/Cubyz/releases/download/R"+i+"/release_info";
+				URL url = new URL(link);
+				ReadableByteChannel rbc = Channels.newChannel(url.openStream());
+				new File(System.getProperty("user.home") + "/.cubyz/" + "R" + i).mkdirs(); // Create the directory.
+				// Stores the release info:
+				FileOutputStream fos = new FileOutputStream(file);
+				fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+				fos.close();
+			}
+		} catch(Exception e) {}
 	}
 	/**
-	 * Connect to github and get an array of all existing releases.
+	 * Reads the title image of a release to be displayed alongside the changelog.
 	 */
-	public static GithubRelease[] downloadReleaseData(String link) {
-		String json = "";
+	public static BufferedImage readOrDownloadImage(File folder) {
+		File imageLocation = new File(folder, "image.png");
+		if(!imageLocation.exists()) {
+			// Download the image:
+			String tag = folder.getName();
+			String link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/image.png";
+			try {
+				DownloadAndFileManager.downloadToFile(imageLocation, link);
+			} catch(IOException e) {
+				System.err.println("Couldn't load the image of release \""+tag+"\"");
+			}
+		}
+		return DownloadAndFileManager.readImage(imageLocation);
+	}
+	/**
+	 * Downloads the executables, assets and such, if necessary and launches the jar file.
+	 */
+	public static void downloadAndLaunchRelease(File folder) {
+		File jarLocation = new File(folder, "main.jar");
+		String tag = folder.getName();
+		if(!jarLocation.exists()) {
+			// The game files need to be downloaded.
+
+			// Addons folder:
+			String link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/addons.zip";
+			try {
+				DownloadAndFileManager.downloadAndUnzip(folder, link);
+			} catch(IOException e) {
+				// That's normal behaviour. Not every release needs this folder.
+			}
+
+			// Assets folder:
+			link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/assets.zip";
+			try {
+				DownloadAndFileManager.downloadAndUnzip(folder, link);
+			} catch(IOException e) {
+				// That's normal behaviour. Not every release needs this folder.
+			}
+
+			// Dependencies:
+			link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/pom.xml";
+			DependencyManager.fetchDependencies(link, System.getProperty("user.home") + "/.cubyz", new File(folder, "pom.xml"));
+
+			// And finally the jar file. This is downloaded last to reduce potential issues when the user closes the application before everything is done.
+			link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/Cubyz.jar";
+			try {
+				DownloadAndFileManager.downloadToFile(jarLocation, link);
+			} catch(IOException e) {
+				try {
+					// The old version 0.6.0 packaged the libraries into the jar file, so there are multiple files for each OS and arch:
+					if(OSInfo.OS_FAMILY.equals("windows")) {
+						if(OSInfo.OS_ARCH.contains("64")) {
+							link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/Cubyz_win_64.jar";
+						} else {
+							link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/Cubyz_win_x86.jar";
+						}
+						DownloadAndFileManager.downloadToFile(jarLocation, link);
+					} else if(OSInfo.OS_FAMILY.equals("unix")) {
+						if(OSInfo.OS_ARCH.contains("64")) {
+							link = "https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/Cubyz_win_64.jar";
+							DownloadAndFileManager.downloadToFile(jarLocation, link);
+						}
+					}
+				} catch(IOException e2) {}
+			}
+		}
+		if(!jarLocation.exists()) {
+			// Something went wrong in the download.
+			JOptionPane.showInternalMessageDialog(null, "Couldn't download file. Please check your internet connection.", "information", JOptionPane.INFORMATION_MESSAGE);
+			return;
+		}
+
+		// Build the classpath:
+		ArrayList<String> libs = DependencyManager.fetchDependencies("https://github.com/PixelGuys/Cubyz/releases/download/"+tag+"/pom.xml", System.getProperty("user.home") + "/.cubyz", new File(folder, "pom.xml"));
+		// Put it all together as a classpath attribute:
+		char classpathSeperator = OSInfo.OS_FAMILY.equals("windows") ? ';' : ':';
+		String classpath = "";
+		for(String lib : libs) {
+			classpath += lib+classpathSeperator;
+		}
+		// Add the executable jar to the classpath:
+		classpath += folder.getAbsolutePath()+"/main.jar";
+
+		// Launch it:
+		ProcessBuilder pb = new ProcessBuilder("java", "-cp", classpath, "io.cubyz.client.GameLauncher");
+		pb.directory(folder);
+		pb.redirectOutput(Redirect.INHERIT);
+		pb.redirectError(Redirect.INHERIT);
 		try {
-			URL url = new URL(link);
-			HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
-			connection.connect();
-			InputStream stream = connection.getInputStream();
-			json = new String(readAllBytes(stream));
-		} catch (MalformedURLException e) {
-			e.printStackTrace();
+			pb.start();
 		} catch (IOException e) {
-			e.printStackTrace();
+			StringWriter sw = new StringWriter();
+			e.printStackTrace(new PrintWriter(sw));
+			String exceptionAsString = sw.toString();
+			JOptionPane.showInternalMessageDialog(null, "Couldn't launch this version. "+exceptionAsString, "information", JOptionPane.INFORMATION_MESSAGE);
 		}
-		JsonElement jo = JsonParser.parseString(json);
-        JsonArray jsonArray = jo.getAsJsonArray();
-        ArrayList<GithubRelease> list = new ArrayList<>();
-        jsonArray.forEach((elem) -> {
-        	JsonObject obj = elem.getAsJsonObject();
-        	GithubRelease release = new GithubRelease();
-        	release.preRelease = obj.get("prerelease").getAsBoolean();
-        	release.date = obj.get("published_at").getAsString();
-        	release.name = obj.get("name").getAsString();
-        	release.version = obj.get("tag_name").getAsString();
-        	release.description = getDescription(obj.get("body"));
-        	ArrayList<GithubAsset> assets = new ArrayList<>();
-        	obj.get("assets").getAsJsonArray().forEach((elem2) -> {
-            	JsonObject obj2 = elem2.getAsJsonObject();
-            	GithubAsset asset = new GithubAsset();
-            	asset.name = obj2.get("name").getAsString();
-            	asset.url = obj2.get("browser_download_url").getAsString();
-            	assets.add(asset);
-        	});
-        	release.assets = assets.toArray(new GithubAsset[0]);
-        	list.add(release);
-        });
-        return list.toArray(new GithubRelease[0]);
-	}
-	public static byte[] readAllBytes(InputStream inputStream) throws IOException {
-		final int bufLen = 1024;
-		byte[] buf = new byte[bufLen];
-		int readLen;
-
-		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-
-		while ((readLen = inputStream.read(buf, 0, bufLen)) != -1)
-			outputStream.write(buf, 0, readLen);
-
-		return outputStream.toByteArray();
 	}
 }