Makes the jar building finally work

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

@@ -8,17 +8,13 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
-import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 
 public class JarBuilder {
 
     private String downloadedBuildToolsVersion = "#124";
-    private String buildDirectory;
-    private String jarDirectory;
+    private final String buildDirectory;
+    private final String jarDirectory;
 
     public JarBuilder(String buildDirectory, String jarDirectory) {
         this.buildDirectory = buildDirectory;
@@ -30,7 +26,7 @@ public class JarBuilder {
      */
     public void buildSpigotJar() {
         downloadBuildTools();
-        ProcessBuilder processBuilder = new ProcessBuilder("java", "-jar", "BuildTools.jar", "--rev",
+        ProcessBuilder processBuilder = new ProcessBuilder("C:\\Program Files\\Java\\jdk-16.0.1\\bin\\java.exe", "-jar", "BuildTools.jar", "--rev",
                 "latest", "--output-dir", jarDirectory);
         executeBuildProcess(processBuilder);
         System.out.println("Finished building spigot .jar. Moving it to the correct location");
@@ -43,7 +39,7 @@ public class JarBuilder {
      */
     public void buildBukkitJar() {
         downloadBuildTools();
-        ProcessBuilder processBuilder = new ProcessBuilder("java", "-jar", "BuildTools.jar", "--compile",
+        ProcessBuilder processBuilder = new ProcessBuilder("C:\\Program Files\\Java\\jdk-16.0.1\\bin\\java.exe", "-jar", "BuildTools.jar", "--compile",
                 "craftbukkit", "--rev", "latest", "--output-dir", jarDirectory);
         executeBuildProcess(processBuilder);
         System.out.println("Finished building craftbukkit .jar. Moving it to the correct location");
@@ -100,29 +96,19 @@ public class JarBuilder {
             Process process = processBuilder.start();
             BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
             BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
-            ScheduledExecutorService builderOutputExecutor = Executors.newSingleThreadScheduledExecutor();
-            builderOutputExecutor.scheduleAtFixedRate(() -> {
-                try {
-                    String readText = CommonFunctions.readBufferedReader(reader);
-                    if (!readText.equals("")) {
-                        writer.write(readText);
-                        writer.flush();
-                    }
-                    if (!process.isAlive()) {
-                        writer.write("Closing process");
-                        writer.flush();
-                        builderOutputExecutor.shutdown();
-                        writer.close();
-                        reader.close();
-                        process.destroyForcibly();
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
-                }
-            }, 1000, 5000, TimeUnit.MILLISECONDS);
-            process.waitFor();
-            System.out.println("Stopped waiting for process");
-        } catch (IOException | InterruptedException e) {
+
+            do {
+                writer.write(CommonFunctions.readBufferedReader(reader));
+            } while (process.isAlive());
+
+            writer.flush();
+
+            if (process.exitValue() == 0) {
+                System.out.println("Jar building process finished successfully.");
+            } else {
+                throw new RuntimeException("Jar building process failed with exit code " + process.exitValue() + ".");
+            }
+        } catch (IOException e) {
             e.printStackTrace();
         }
     }

src/test/java/net/knarcraft/minecraftserverlauncher/utility/JarBuilderTest.java

@@ -1,7 +1,6 @@
 package net.knarcraft.minecraftserverlauncher.utility;
 
 import net.knarcraft.minecraftserverlauncher.Main;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Order;
@@ -34,13 +33,21 @@ public class JarBuilderTest {
     @Test
     @Order(3)
     public void buildLatestSpigotJarTest() {
+        File spigotFile = new File(jarDirectory + "SpigotLatest.jar");
+        if (spigotFile.exists() && !spigotFile.delete()) {
+            throw new IllegalArgumentException("Unable to remove existing spigot .jar");
+        }
         jarBuilder.buildSpigotJar();
-        assertTrue(new File(jarDirectory + "SpigotLatest.jar").exists());
+        assertTrue(spigotFile.exists());
     }
 
     @Test
     @Order(4)
     public void buildLatestBukkitJarTest() {
+        File bukkitFile = new File(jarDirectory + "BukkitLatest.jar");
+        if (bukkitFile.exists() && !bukkitFile.delete()) {
+            throw new IllegalArgumentException("Unable to remove existing bukkit .jar");
+        }
         jarBuilder.buildBukkitJar();
         assertTrue(new File(jarDirectory + "BukkitLatest.jar").exists());
     }