Comment and code additions

More comments are added.
More work on downloading server jars is done.

src/Main.java

@@ -25,10 +25,11 @@ public class Main {
 	 */
 	private static void addServerTypes() {
 		//This could be changed to read from a list which is downloaded to the user's computer.
-		serverTypes.add(new ServerType("Vanilla", new String[]{"Latest", "1.12", "1.11.2", "1.10.2", "1.9.4", "1.8.9", "1.7.10", "1.6.4", "1.5.2", "1.4.7", "1.3.2", "1.2.5"}));
+		serverTypes.add(new AdvancedServerType("Vanilla", new String[]{"Latest", "1.12", "1.11.2", "1.10.2", "1.9.4", "1.8.9", "1.7.10", "1.6.4", "1.5.2", "1.4.7", "1.3.2", "1.2.5"}, "https://launchermeta.mojang.com/mc/game/version_manifest.json", "\"release\":\"", "\"", "https://s3.amazonaws.com/Minecraft.Download/versions/", "/minecraft_server."));
-		serverTypes.add(new ServerType("Snapshot", new String[]{"Latest"}));
+		serverTypes.add(new AdvancedServerType("Snapshot", new String[]{"Latest"}, "https://launchermeta.mojang.com/mc/game/version_manifest.json", "\"snapshot\":\"", "\"", "https://s3.amazonaws.com/Minecraft.Download/versions/", "/minecraft_server."));
 		serverTypes.add(new AdvancedServerType("SpongeVanilla", new String[]{"1.11.2", "1.10.2", "1.8.9"}, "https://dl-api.spongepowered.org/v1/org.spongepowered/spongevanilla/downloads?type=stable&minecraft=", "\"version\":\"", "\",", "https://repo.spongepowered.org/maven/org/spongepowered/spongevanilla/", "/spongevanilla-"));
-		serverTypes.add(new ServerType("Spigot", new String[]{"1.12", "1.11.2", "1.10.2", "1.9.4", "1.9", "1.8.8", "1.7.10", "1.6.4", "1.5.2", "1.4.7"}));
+		serverTypes.add(new AdvancedServerType("Bungee", new String[]{"Latest"}, "https://ci.md-5.net/job/BungeeCord/lastSuccessfulBuild/artifact/bootstrap/target/", "Artifacts of BungeeCord #", " ", "http://ci.md-5.net/job/BungeeCord/lastSuccessfulBuild/artifact/bootstrap/target/BungeeCord.jar", ""));
+		serverTypes.add(new ServerType("Spigot", new String[]{"1.12.2", "1.11.2", "1.10.2", "1.9.4", "1.9", "1.8.8", "1.7.10", "1.6.4", "1.5.2", "1.4.7"}));
 		serverTypes.add(new ServerType("MCPCplus", new String[]{"1.6.4", "1.6.2", "1.5.2", "1.4.7"}));
 		serverTypes.add(new ServerType("Craftbukkit", new String[]{"1.12", "1.11.2", "1.10.2", "1.9.4", "1.8.8", "1.7.10", "1.6.4", "1.5.2", "1.4.6", "1.3.2", "1.2.5", "1.1", "1.0"}));
 		serverTypes.add(new ServerType("Custom", new String[]{""}));

src/net/knarcraft/serverlauncher/server/Server.java

@@ -11,11 +11,14 @@ import java.util.ArrayList;
 import java.io.FileNotFoundException;
 /* Contains all necessary information to create, run and manage a Minecraft server. */
 public class Server {
+    /** Necessary urls for downloading from knarcraft.net */
 	private static final String BASEURL = "https://knarcraft.net/Api/Download/bungeeminecraftserverlauncher/jars"; //The url we download jar files from.
 	private static final String BUKKITURL = BASEURL + "/Bukkit/";
 	private static final String MCPCURL = BASEURL + "/MCPC+/";
 	private static final String SPIGOTURL = BASEURL + "/Spigot/";
-	private static String[] ramList = {"512M", "1G", "2G", "3G", "4G", "5G", "6G", "7G", "8G", "9G", "10G", "11G", "12G", "13G", "14G", "15G", "16G"};
+	/** Available ram sizes. For GUI dropdown */
+	private static final String[] ramList = {"512M", "1G", "2G", "3G", "4G", "5G", "6G", "7G", "8G", "9G", "10G", "11G", "12G", "13G", "14G", "15G", "16G"};
+
 	private String name;
 	private String path;
 	private boolean enabled;
@@ -76,12 +79,17 @@ public class Server {
      * Custom files must exist, or trigger a message.
      */
 	public void downloadJar() throws FileNotFoundException {
-        if (!new File(this.path + "\\" + this.getType()).isFile()) {
+	    File file = new File(this.path + "\\" + this.getType());
+        Path filePath = Paths.get(this.path + "\\" + this.getType());
             switch (this.type.getName()) {
                 case "Custom":
-                    throw new FileNotFoundException("Specified custom jar was not found.");
+                    if (!file.isFile()) {
+                        throw new FileNotFoundException("Specified custom jar was not found.");
+                    }
                 case "Spigot":
-                    staticJar(SPIGOTURL);
+                    if (!file.isFile()) {
+                        staticJar(SPIGOTURL);
+                    }
                     break;
                 case "Craftbukkit":
                     staticJar(BUKKITURL);
@@ -90,17 +98,27 @@ public class Server {
                     staticJar(MCPCURL);
                     break;
                 case "Vanilla":
+                case "Snapshot":
                     if (this.serverVersion.equals("Latest")) {
-
+                        String versionText;
+                        try {
+                            versionText = readFile(this.type.getVersionURL());
+                        } catch (IOException e) {
+                            throw new FileNotFoundException("Version file could not be downloaded.");
+                        }
+                        String newestVersion = stringBetween(versionText, type.getSrcStart(), type.getSrcEnd());
+                        boolean success = downloadFile(type.getDownloadURL() + newestVersion + type.getDownloadURLPart() + newestVersion + ".jar", filePath);
+                        if (!success) {
+                            throw new FileNotFoundException("Jar file could not be downloaded.");
+                        }
                     } else {
-
+                        downloadFile(type.getDownloadURL() + this.serverVersion + type.getDownloadURLPart() + this.serverVersion + ".jar", filePath);
                     }
                     break;
                 case "Sponge":
                     staticJar(type.getVersionURL(), type.getSrcStart(), type.getSrcEnd(), type.getDownloadURL(), type.getDownloadURLPart(), this.getType());
             }
             //TODO: Download a jar file based on version and type. Throw an error if the file could not be found or fetched.
-        }
     }
 
     private boolean staticJar(String url) {
@@ -112,24 +130,15 @@ public class Server {
     }
 
 	/**
-	 * Reads the first line of a file from a website.
+	 * Reads a file from a website.
 	 * This is used to find the newest version of the software.
 	 *
 	 * @param path	The full url of the file to read.
 	 * @return		True if successfull. False otherwise.
 	 */
-	public static boolean readFile(String path) {
+	private static String readFile(String path) throws IOException {
-		//We might need to change this to look for specific lines in the file to find vanilla and snapshot versions.
+	    URL url = new URL(path);
-		//The version should probably be returned. Empty or null on failiure.
+	    return new Scanner(url.openStream()).useDelimiter("\\Z").next();
-		try {
-			URL url = new URL(path);
-			Scanner s = new Scanner(url.openStream());
-			System.out.println(s.next());
-			return true;
-		} catch (IOException e) {
-			System.out.println("Error");
-			return false;
-		}
 	}
 
 	/**
@@ -141,16 +150,23 @@ public class Server {
 	 */
 	private static boolean downloadFile(String path, Path outfile) {
 		try {
-			URL url = new URL("https://knarcraft.net/Api/View/Jawns/Jawns%20instructions.txt");
+			URL url = new URL(path);
 			InputStream in = url.openStream();
 			Files.copy(in, outfile, StandardCopyOption.REPLACE_EXISTING);
 			return true;
 		} catch (IOException e) {
-			System.out.println("Error");
 			return false;
 		}
 	}
 
+    /**
+     * Finds a substring between two substrings in a string.
+     *
+     * @param string    The string containing the substrings.
+     * @param start     The substring before the wanted substring.
+     * @param end       The substring after the wanted substring.
+     * @return          The wanted substring.
+     */
 	private String stringBetween(String string, String start, String end) {
         return string.substring(string.indexOf(start) + 1 + start.length(), string.indexOf(end));
     }