Enhance updater functionality: backup current jar before downloading updates

Author: Crazygiscool

src/main/java/me/crazyg/everything/utils/Updater.java

@@ -5,6 +5,7 @@
 import com.google.gson.JsonParser;
 import java.io.BufferedReader;
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -96,29 +97,53 @@ private void downloadUpdate() {
 
         CompletableFuture.runAsync(() -> {
             try {
+                // Prepare update folder
                 File updateFolder = new File(plugin.getDataFolder().getParentFile(), UPDATE_FOLDER);
                 if (!updateFolder.exists()) {
                     updateFolder.mkdir();
                 }
 
-                String fileName = "everything-" + latestVersion + ".jar";
-                File outputFile = new File(updateFolder, fileName);
+                // Get the current plugin jar file
+                File currentJar = null;
+                try {
+                    currentJar = new File(plugin.getClass().getProtectionDomain().getCodeSource().getLocation().toURI());
+                } catch (Exception e) {
+                    plugin.getLogger().severe(Component.text("Could not determine the current plugin JAR file: " + e.getMessage())
+                        .color(NamedTextColor.RED)
+                        .toString());
+                    return;
+                }
+                if (currentJar == null || !currentJar.exists()) {
+                    plugin.getLogger().severe(Component.text("Could not determine the current plugin JAR file!")
+                        .color(NamedTextColor.RED)
+                        .toString());
+                    return;
+                }
+
+                // Backup the current jar to the update folder
+                File backupFile = new File(updateFolder, currentJar.getName() + ".bak-" + currentVersion);
+                try (FileInputStream fis = new FileInputStream(currentJar); FileOutputStream fos = new FileOutputStream(backupFile)) {
+                    byte[] buffer = new byte[1024];
+                    int len;
+                    while ((len = fis.read(buffer)) > 0) {
+                        fos.write(buffer, 0, len);
+                    }
+                }
 
+                // Download the new jar and overwrite the current one
                 URL url = URI.create(downloadUrl).toURL();
                 HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                 connection.setRequestProperty("Accept", "application/octet-stream");
 
-                try (InputStream in = connection.getInputStream();
-                     FileOutputStream out = new FileOutputStream(outputFile)) {
-                    byte[] buffer = new byte[1024];
-                    int bytesRead;
-                    long totalBytesRead = 0;
-                    long fileSize = connection.getContentLengthLong();
+                long fileSize = connection.getContentLengthLong();
+                long totalBytesRead = 0;
+                int bytesRead;
+                byte[] buffer = new byte[1024];
 
+                try (InputStream in = connection.getInputStream(); FileOutputStream out = new FileOutputStream(currentJar)) {
                     while ((bytesRead = in.read(buffer)) != -1) {
                         out.write(buffer, 0, bytesRead);
                         totalBytesRead += bytesRead;
-                        
                         if (fileSize > 0) {
                             int progress = (int) ((totalBytesRead * 100) / fileSize);
                             if (progress % 5 == 0) {
@@ -131,16 +156,18 @@ private void downloadUpdate() {
                 }
 
                 plugin.getLogger().info(Component.text()
-                    .append(Component.text("Update downloaded successfully to: ").color(NamedTextColor.GREEN))
-                    .append(Component.text(outputFile.getAbsolutePath()).color(NamedTextColor.WHITE))
+                    .append(Component.text("Update downloaded and replaced plugin jar: ").color(NamedTextColor.GREEN))
+                    .append(Component.text(currentJar.getAbsolutePath()).color(NamedTextColor.WHITE))
+                    .build().toString());
+                plugin.getLogger().info(Component.text()
+                    .append(Component.text("Backup of old jar saved to: ").color(NamedTextColor.YELLOW))
+                    .append(Component.text(backupFile.getAbsolutePath()).color(NamedTextColor.WHITE))
                     .build().toString());
-                
                 plugin.getLogger().info(Component.text("Please restart your server to apply the update.")
                     .color(NamedTextColor.YELLOW)
                     .toString());
-
-            } catch (IOException e) {
-                plugin.getLogger().severe(Component.text("Failed to download update: " + e.getMessage())
+            } catch (Exception e) {
+                plugin.getLogger().severe(Component.text("Failed to download or replace update: " + e.getMessage())
                     .color(NamedTextColor.RED)
                     .toString());
             }