Makes the software build Spigot and CraftBukkit jars if the latest version is chosen

src/main/java/net/knarcraft/minecraftserverlauncher/server/servertypes/CraftBukkit.java

@@ -1,5 +1,10 @@
 package net.knarcraft.minecraftserverlauncher.server.servertypes;
 
+import net.knarcraft.minecraftserverlauncher.Main;
+import net.knarcraft.minecraftserverlauncher.profile.ServerLauncherController;
+import net.knarcraft.minecraftserverlauncher.userinterface.GUI;
+import net.knarcraft.minecraftserverlauncher.utility.JarBuilder;
+
 import java.io.File;
 import java.nio.file.Paths;
 
@@ -31,7 +36,31 @@ public class CraftBukkit extends AbstractServerType {
         String targetFile = this.getName() + version + ".jar";
         String file = downloadURLPart + version + ".jar";
         File filePath = new File(folder + targetFile);
-        return filePath.isFile() || downloadFile(downloadURL + file, Paths.get(filePath.toURI()));
+
+        if (version.equals("Latest")) {
+            return filePath.isFile() || buildJar(folder);
+        } else {
+            return filePath.isFile() || downloadFile(downloadURL + file, Paths.get(filePath.toURI()));
+        }
+    }
+
+    /**
+     * Builds the necessary .jar file
+     *
+     * @param folder <p>The folder the build file should be moved to</p>
+     * @return <p>True if the build was successful</p>
+     */
+    private boolean buildJar(String folder) {
+        String buildToolsDirectory = Main.getApplicationWorkDirectory() + File.separator + "files" + File.separator +
+                "BuildTools" + File.separator;
+
+        GUI gui = ServerLauncherController.getInstance().getGUI();
+        JarBuilder jarBuilder = new JarBuilder(buildToolsDirectory, folder, gui);
+        if (this instanceof Spigot) {
+            return jarBuilder.buildSpigotJar();
+        } else {
+            return jarBuilder.buildBukkitJar();
+        }
     }
 
 }

src/main/java/net/knarcraft/minecraftserverlauncher/utility/JarBuilder.java

@@ -42,24 +42,32 @@ public class JarBuilder {
     /**
      * Builds the latest version of the spigot .jar file
      */
-    public void buildSpigotJar() {
+    public boolean buildSpigotJar() {
+        gui.setStatus("Building Spigot jar ...");
         downloadBuildTools();
         ProcessBuilder processBuilder = new ProcessBuilder(javaCommand, "-jar", "BuildTools.jar", "--rev",
                 "latest", "--output-dir", jarDirectory);
         if (executeBuildProcess(processBuilder) && moveBuiltJar("spigot-", "SpigotLatest.jar")) {
             gui.setStatus("Finished moving spigot.jar");
+            return true;
+        } else {
+            return false;
         }
     }
 
     /**
      * Builds the latest version of the craftbukkit .jar file
      */
-    public void buildBukkitJar() {
+    public boolean buildBukkitJar() {
+        gui.setStatus("Building Bukkit jar ...");
         downloadBuildTools();
         ProcessBuilder processBuilder = new ProcessBuilder(javaCommand, "-jar", "BuildTools.jar", "--compile",
                 "craftbukkit", "--rev", "latest", "--output-dir", jarDirectory);
         if (executeBuildProcess(processBuilder) && moveBuiltJar("craftbukkit-", "BukkitLatest.jar")) {
             gui.setStatus("Finished moving craftbukkit.jar");
+            return true;
+        } else {
+            return false;
         }
     }
 
@@ -133,7 +141,7 @@ public class JarBuilder {
             writer.flush();
 
             if (process.exitValue() == 0) {
-                gui.showMessage("Jar building process finished successfully.");
+                gui.setStatus("Jar building process finished successfully.");
                 return true;
             } else {
                 gui.showError("Jar building process failed with exit code " + process.exitValue() +