Refactored code.

Added startup message on the first start after restoring a backup.
Adjusted text color.

8 files changed, 237 insertions, 92 deletions

diff --git a/src/main/java/com/keuin/kbackupfabric/KBCommandHandler.java b/src/main/java/com/keuin/kbackupfabric/KBCommands.java
index 943fb68..c636a0d 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBCommandHandler.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBCommands.java
@@ -1,5 +1,7 @@
 package com.keuin.kbackupfabric;
 
+import com.keuin.kbackupfabric.data.BackupMetadata;
+import com.keuin.kbackupfabric.util.PrintUtil;
 import com.keuin.kbackupfabric.worker.BackupWorker;
 import com.keuin.kbackupfabric.worker.RestoreWorker;
 import com.mojang.brigadier.arguments.StringArgumentType;
@@ -13,10 +15,9 @@ import java.time.format.DateTimeFormatter;
 import java.util.HashMap;
 
 import static com.keuin.kbackupfabric.util.BackupFilesystemUtil.*;
-import static com.keuin.kbackupfabric.util.PrintUtil.debug;
-import static com.keuin.kbackupfabric.util.PrintUtil.message;
+import static com.keuin.kbackupfabric.util.PrintUtil.*;
 
-public final class KBCommandHandler {
+public final class KBCommands {
 
 
     private static final int SUCCESS = 1;
@@ -33,18 +34,18 @@ public final class KBCommandHandler {
      * @return stat code.
      */
     public static int help(CommandContext<ServerCommandSource> context) {
-        message(context, "==== KBackup Manual ====");
-        message(context, "/kb   /kb help            Print help menu.");
-        message(context, "/kb list                  Show all backups.");
-        message(context, "/kb backup [backup_name]  Backup world, nether, end to backup_name. By default, the name is current system time.");
-        message(context, "/kb restore <backup_name> Delete current three worlds, restore the older version from given backup. By default, this command is identical with /kb list.");
-        message(context, "/kb confirm               Confirm and start restoring.");
-        message(context, "/kb cancel                Cancel the restoration to be confirmed. If cancelled, /kb confirm will not effect without another valid /kb restore command.");
+        msgInfo(context, "==== KBackup Manual ====");
+        msgInfo(context, "/kb       /kb help        Print help menu.");
+        msgInfo(context, "/kb list                  Show all backups.");
+        msgInfo(context, "/kb backup [backup_name]  Backup the whole level to backup_name. The default name is current system time.");
+        msgInfo(context, "/kb restore <backup_name> Delete the whole current level and restore from given backup. /kb restore is identical with /kb list.");
+        msgInfo(context, "/kb confirm               Confirm and start restoring.");
+        msgInfo(context, "/kb cancel                Cancel the restoration to be confirmed. If cancelled, /kb confirm will not run.");
         return SUCCESS;
     }
 
     public static int list(CommandContext<ServerCommandSource> context) {
-        message(context, "Available backups: (file is not checked, manipulation may affect this plugin)");
+        msgInfo(context, "Available backups: (file is not checked, manipulation may affect this plugin)");
         MinecraftServer server = context.getSource().getMinecraftServer();
         File[] files = getBackupSaveDirectory(server).listFiles(
                 (dir, name) -> dir.isDirectory() && name.toLowerCase().endsWith(".zip") && name.toLowerCase().startsWith(getBackupFileNamePrefix())
@@ -56,7 +57,7 @@ public final class KBCommandHandler {
                 ++i;
                 String backupName = getBackupName(file.getName());
                 backupIndexNameMapper.put(i, backupName);
-                message(context, String.format("[%d] %s, size: %.1fMB", i, backupName, file.length() * 1.0 / 1024 / 1024));
+                msgInfo(context, String.format("[%d] %s, size: %.1fMB", i, backupName, file.length() * 1.0 / 1024 / 1024));
             }
         }
         return SUCCESS;
@@ -74,7 +75,7 @@ public final class KBCommandHandler {
         if (backupName.matches("[0-9]*")) {
             // Numeric param is not allowed
             backupName = String.format("a%s", backupName);
-            message(context, String.format("Pure numeric name is not allowed. Renamed to %s", backupName));
+            msgWarn(context, String.format("Pure numeric name is not allowed. Renamed to %s", backupName));
         }
         return doBackup(context, backupName);
     }
@@ -104,13 +105,13 @@ public final class KBCommandHandler {
         // Validate backupName
         if (!isBackupNameValid(backupName, server)) {
             // Invalid backupName
-            message(context, "Invalid backup name! Please check your input. The list index number is also valid.", false);
+            msgErr(context, "Invalid backup name! Please check your input. The list index number is also valid.", false);
             return FAILED;
         }
 
         // Update confirm pending variable
         restoreBackupNameToBeConfirmed = backupName;
-        message(context, String.format("WARNING: You will LOST YOUR CURRENT WORLD COMPLETELY! It will be replaced with the backup %s . Please use /kb confirm to proceed executing.", restoreBackupNameToBeConfirmed), true);
+        msgWarn(context, String.format("WARNING: You will LOST YOUR CURRENT WORLD COMPLETELY! It will be replaced with the backup %s . Please use /kb confirm to proceed executing.", restoreBackupNameToBeConfirmed), true);
         return SUCCESS;
     }
 
@@ -129,7 +130,8 @@ public final class KBCommandHandler {
     }
 
     private static int doBackup(CommandContext<ServerCommandSource> context, String backupName) {
-        BackupWorker.invoke(context, backupName);
+        BackupMetadata metadata = new BackupMetadata(System.currentTimeMillis(), backupName);
+        BackupWorker.invoke(context, backupName, metadata);
         return SUCCESS;
     }
 
@@ -141,22 +143,22 @@ public final class KBCommandHandler {
      */
     public static int confirm(CommandContext<ServerCommandSource> context) {
         if (restoreBackupNameToBeConfirmed == null) {
-            message(context, "Nothing to be confirmed. Please execute /kb restore <backup_name> first.");
+            msgInfo(context, "Nothing to be confirmed. Please execute /kb restore <backup_name> first.");
             return FAILED;
         }
 
         // do restore to backupName
         String backupName = restoreBackupNameToBeConfirmed;
-        message(context, String.format("Restoring worlds to %s ...", backupName), true);
+        PrintUtil.msgInfo(context, String.format("Restoring worlds to %s ...", backupName), true);
 
         // Get server
         MinecraftServer server = context.getSource().getMinecraftServer();
         String backupFileName = getBackupFileName(backupName);
         debug("Backup file name: " + backupFileName);
         File backupFile = new File(getBackupSaveDirectory(server), backupFileName);
-        message(context, "Server will shutdown in a few seconds, depended on your world size and the disk speed, the restore progress may take seconds or minutes.", true);
-        message(context, "Please do not force the server stop, or the level would be broken.", true);
-        message(context, "After it shuts down, please restart the server manually.", true);
+        PrintUtil.msgInfo(context, "Server will shutdown in a few seconds, depended on your world size and the disk speed, the restore progress may take seconds or minutes.", true);
+        PrintUtil.msgInfo(context, "Please do not force the server stop, or the level would be broken.", true);
+        PrintUtil.msgInfo(context, "After it shuts down, please restart the server manually.", true);
         final int WAIT_SECONDS = 10;
         for (int i = 0; i < WAIT_SECONDS; ++i) {
             try {
@@ -164,7 +166,7 @@ public final class KBCommandHandler {
             } catch (InterruptedException ignored) {
             }
         }
-        message(context, "Shutting down ...", true);
+        PrintUtil.msgInfo(context, "Shutting down ...", true);
         RestoreWorker.invoke(server, backupFile.getPath(), getLevelPath(server));
         return SUCCESS;
     }
@@ -178,10 +180,10 @@ public final class KBCommandHandler {
     public static int cancel(CommandContext<ServerCommandSource> context) {
         if (restoreBackupNameToBeConfirmed != null) {
             restoreBackupNameToBeConfirmed = null;
-            message(context, "The restoration is cancelled.", true);
+            PrintUtil.msgInfo(context, "The restoration is cancelled.", true);
             return SUCCESS;
         } else {
-            message(context, "Nothing to cancel.");
+            msgErr(context, "Nothing to cancel.");
             return FAILED;
         }
     }
diff --git a/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java b/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java
new file mode 100644
index 0000000..4f0f1ff
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java
@@ -0,0 +1,65 @@
+package com.keuin.kbackupfabric;
+
+import com.keuin.kbackupfabric.data.BackupMetadata;
+import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.server.ServerStartCallback;
+import net.fabricmc.fabric.api.registry.CommandRegistry;
+import net.minecraft.server.MinecraftServer;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+import static com.keuin.kbackupfabric.util.PrintUtil.debug;
+import static com.keuin.kbackupfabric.util.PrintUtil.info;
+import static org.apache.commons.io.FileUtils.forceDelete;
+
+/**
+ * This is the Main file of this plugin.
+ * It contains all events, including the init event.
+ */
+public final class KBPluginEvents implements ModInitializer, ServerStartCallback {
+    @Override
+    public void onInitialize() {
+        System.out.println("Initializing KBackup...");
+        CommandRegistry.INSTANCE.register(false, KBRegister::registerCommands);
+        ServerStartCallback.EVENT.register(this);
+    }
+
+    @Override
+    public void onStartServer(MinecraftServer server) {
+        // When the server starts, we check if we have just recovered from a backup.
+        // If so, then we print some message.
+        debug("KBackup onStartServer");
+        // TODO:
+        // Check
+        try {
+            File levelDirectory = new File(server.getRunDirectory(), server.getLevelName());
+            File metadataFile = new File(levelDirectory, BackupMetadata.metadataFileName);
+            if (metadataFile.exists()) {
+                // Metadata exists. Deserialize.
+                BackupMetadata metadata = null;
+                FileInputStream fileInputStream = new FileInputStream(metadataFile);
+                ObjectInputStream in = new ObjectInputStream(fileInputStream);
+                metadata = (BackupMetadata) in.readObject();
+                in.close();
+                fileInputStream.close();
+
+                // Print metadata
+                info("Recovered from previous backup:");
+                info("Backup Name: " + metadata.getBackupName());
+                info("Create Time: " + (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")).format(new Date(metadata.getBackupTime())));
+
+                // Delete metadata file
+                if (!metadataFile.delete()) {
+                    System.gc();
+                    forceDelete(metadataFile);
+                }
+            }
+        } catch (IOException | ClassNotFoundException ignored) {
+        }
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/KBPluginInitializer.java b/src/main/java/com/keuin/kbackupfabric/KBPluginInitializer.java
deleted file mode 100644
index c3582c7..0000000
--- a/src/main/java/com/keuin/kbackupfabric/KBPluginInitializer.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package com.keuin.kbackupfabric;
-
-import net.fabricmc.api.ModInitializer;
-import net.fabricmc.fabric.api.registry.CommandRegistry;
-
-public final class KBPluginInitializer implements ModInitializer {
-    @Override
-    public void onInitialize() {
-        System.out.println("Initializing KBackup...");
-        CommandRegistry.INSTANCE.register(false, KBCommandRegister::register);
-    }
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/KBCommandRegister.java b/src/main/java/com/keuin/kbackupfabric/KBRegister.java
index a9dcb38..11f05a1 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBCommandRegister.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBRegister.java
@@ -6,27 +6,27 @@ import com.mojang.brigadier.arguments.StringArgumentType;
 import net.minecraft.server.command.CommandManager;
 import net.minecraft.server.command.ServerCommandSource;
 
-public final class KBCommandRegister {
+public final class KBRegister {
     // First make method to register
-    public static void register(CommandDispatcher<ServerCommandSource> dispatcher) {
+    public static void registerCommands(CommandDispatcher<ServerCommandSource> dispatcher) {
         // register /kb and /kb help for help menu
-        dispatcher.register(CommandManager.literal("kb").executes(KBCommandHandler::help));
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("help").executes(KBCommandHandler::help)));
+        dispatcher.register(CommandManager.literal("kb").executes(KBCommands::help));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("help").executes(KBCommands::help)));
 
         // register /kb list for showing the backup list. OP is required.
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("list").requires(PermissionValidator::op).executes(KBCommandHandler::list)));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("list").requires(PermissionValidator::op).executes(KBCommands::list)));
 
         // register /kb backup [name] for performing backup. OP is required.
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(CommandManager.argument("backupName", StringArgumentType.string()).requires(PermissionValidator::op).executes(KBCommandHandler::backup)).requires(PermissionValidator::op).executes(KBCommandHandler::backupWithDefaultName)));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(CommandManager.argument("backupName", StringArgumentType.string()).requires(PermissionValidator::op).executes(KBCommands::backup)).requires(PermissionValidator::op).executes(KBCommands::backupWithDefaultName)));
 
         // register /kb restore <name> for performing restore. OP is required.
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("restore").then(CommandManager.argument("backupName", StringArgumentType.string()).requires(PermissionValidator::op).executes(KBCommandHandler::restore)).executes(KBCommandHandler::list)));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("restore").then(CommandManager.argument("backupName", StringArgumentType.string()).requires(PermissionValidator::op).executes(KBCommands::restore)).executes(KBCommands::list)));
 
         // register /kb confirm for confirming the execution. OP is required.
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("confirm").requires(PermissionValidator::op).executes(KBCommandHandler::confirm)));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("confirm").requires(PermissionValidator::op).executes(KBCommands::confirm)));
 
         // register /kb cancel for cancelling the execution to be confirmed. OP is required.
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("cancel").requires(PermissionValidator::op).executes(KBCommandHandler::cancel)));
+        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("cancel").requires(PermissionValidator::op).executes(KBCommands::cancel)));
 
     }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/data/BackupMetadata.java b/src/main/java/com/keuin/kbackupfabric/data/BackupMetadata.java
new file mode 100644
index 0000000..48670c6
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/data/BackupMetadata.java
@@ -0,0 +1,23 @@
+package com.keuin.kbackupfabric.data;
+
+import java.io.Serializable;
+
+public class BackupMetadata implements Serializable {
+    public static final String metadataFileName = "kbackup_metadata";
+    private static final long serialVersionUID = 1L;
+    private final long BackupTime;
+    private final String backupName;
+
+    public BackupMetadata(long backupTime, String backupName) {
+        BackupTime = backupTime;
+        this.backupName = backupName;
+    }
+
+    public long getBackupTime() {
+        return BackupTime;
+    }
+
+    public String getBackupName() {
+        return backupName;
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/PrintUtil.java b/src/main/java/com/keuin/kbackupfabric/util/PrintUtil.java
index 8c8a687..4b93d17 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/PrintUtil.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/PrintUtil.java
@@ -3,27 +3,60 @@ package com.keuin.kbackupfabric.util;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.text.LiteralText;
+import net.minecraft.text.Style;
+import net.minecraft.text.Text;
+import net.minecraft.util.Formatting;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public final class PrintUtil {
 
     private static final Logger LOGGER = LogManager.getLogger();
+
     private static final boolean printDebugMessages = true;
     private static final boolean printErrorMessages = true;
     private static final boolean printInfoMessages = true;
+
     private static final Object syncDebug = new Object();
     private static final Object syncError = new Object();
     private static final Object syncInfo = new Object();
     private static final Object syncMessage = new Object();
 
-    public static void message(CommandContext<ServerCommandSource> context, String messageText) {
-        message(context, messageText, false);
+    private static final Style infoStyle = new Style().setColor(Formatting.WHITE);
+    private static final Style debugStyle = new Style().setUnderline(true);
+    private static final Style warnStyle = new Style().setColor(Formatting.YELLOW);
+    private static final Style errorStyle = new Style().setColor(Formatting.DARK_RED);
+
+
+    public static CommandContext<ServerCommandSource> msgInfo(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgInfo(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgWarn(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgWarn(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgErr(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgErr(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgInfo(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, infoStyle);
+    }
+
+    public static CommandContext<ServerCommandSource> msgWarn(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, warnStyle);
+    }
+
+    public static CommandContext<ServerCommandSource> msgErr(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, errorStyle);
     }
 
-    public static CommandContext<ServerCommandSource> message(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+    public static CommandContext<ServerCommandSource> message(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps, Style style) {
         synchronized (syncMessage) {
-            context.getSource().sendFeedback(new LiteralText("[KBackup] " + messageText), broadcastToOps);
+            Text text = new LiteralText(messageText);
+            text.setStyle(style);
+            context.getSource().sendFeedback(text, broadcastToOps);
         }
         return context;
     }
@@ -31,8 +64,8 @@ public final class PrintUtil {
     public static void debug(String message) {
         synchronized (syncDebug) {
             if (printDebugMessages) {
-                System.out.println(String.format("[DEBUG] [KBackup] %s", message));
-                LOGGER.debug(message);
+                //System.out.println(String.format("[DBG] [KB] %s", message));
+                LOGGER.debug("[KB][DEBUG] " + message);
             }
         }
     }
@@ -40,8 +73,8 @@ public final class PrintUtil {
     public static void error(String message) {
         synchronized (syncError) {
             if (printErrorMessages) {
-                System.out.println(String.format("[ERROR] [KBackup] %s", message));
-                LOGGER.error(message);
+                //System.out.println(String.format("[ERR] [KB] %s", message));
+                LOGGER.error("[KB][ERROR]" + message);
             }
         }
     }
@@ -49,8 +82,8 @@ public final class PrintUtil {
     public static void info(String message) {
         synchronized (syncInfo) {
             if (printInfoMessages) {
-                System.out.println(String.format("[INFO] [KBackup] %s", message));
-                LOGGER.info(message);
+                //System.out.println(String.format("[INF] [KB] %s", message));
+                LOGGER.info("[KB][INFO] " + message);
             }
         }
     }
diff --git a/src/main/java/com/keuin/kbackupfabric/util/ZipUtil.java b/src/main/java/com/keuin/kbackupfabric/util/ZipUtil.java
index fec4436..5297dda 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/ZipUtil.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/ZipUtil.java
@@ -1,5 +1,7 @@
 package com.keuin.kbackupfabric.util;
 
+import com.keuin.kbackupfabric.data.BackupMetadata;
+
 import java.io.*;
 import java.util.Enumeration;
 import java.util.zip.*;
@@ -9,12 +11,12 @@ public final class ZipUtil {
     /**
      * 递归压缩文件夹
      *
-     * @param srcRootDir 压缩文件夹根目录的子路径
-     * @param file       当前递归压缩的文件或目录对象
-     * @param zos        压缩文件存储对象
+     * @param srcRootDir      压缩文件夹根目录的子路径
+     * @param file            当前递归压缩的文件或目录对象
+     * @param zipOutputStream 压缩文件存储对象
      * @throws IOException IO Error
      */
-    private static void zip(String srcRootDir, File file, ZipOutputStream zos) throws IOException {
+    private static void zip(String srcRootDir, File file, ZipOutputStream zipOutputStream) throws IOException {
         if (file == null) {
             return;
         }
@@ -31,13 +33,13 @@ public final class ZipUtil {
                 subPath = subPath.substring(srcRootDir.length() + File.separator.length());
             }
             ZipEntry entry = new ZipEntry(subPath);
-            zos.putNextEntry(entry);
-            BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
-            while ((count = bis.read(data, 0, bufferLen)) != -1) {
-                zos.write(data, 0, count);
+            zipOutputStream.putNextEntry(entry);
+            BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(file));
+            while ((count = inputStream.read(data, 0, bufferLen)) != -1) {
+                zipOutputStream.write(data, 0, count);
             }
-            bis.close();
-            zos.closeEntry();
+            inputStream.close();
+            zipOutputStream.closeEntry();
         }
         // 如果是目录，则压缩整个目录
         else {
@@ -45,11 +47,16 @@ public final class ZipUtil {
             File[] childFileList = file.listFiles();
             if (childFileList != null) {
                 for (File value : childFileList)
-                    zip(srcRootDir, value, zos);
+                    zip(srcRootDir, value, zipOutputStream);
             }
         }
     }
 
+//    public static void makeZipBackup(String srcPath, String zipPath, String zipFileName) throws IOException, ZipUtilException {
+//        zip(srcPath, zipPath, zipFileName, null);
+//    }
+
+
     /**
      * 对文件或文件目录进行压缩
      *
@@ -59,12 +66,12 @@ public final class ZipUtil {
      * @throws IOException      IO Error
      * @throws ZipUtilException General exception, such as loop recursion or invalid input.
      */
-    public static void zip(String srcPath, String zipPath, String zipFileName) throws IOException, ZipUtilException {
+    public static void makeBackupZip(String srcPath, String zipPath, String zipFileName, BackupMetadata backupMetadata) throws IOException, ZipUtilException {
         if (srcPath.isEmpty() || zipPath.isEmpty() || zipFileName.isEmpty()) {
             throw new ZipUtilException("Parameter for zip() contains null.");
         }
-        CheckedOutputStream cos;
-        ZipOutputStream zos = null;
+        CheckedOutputStream checkedOutputStream;
+        ZipOutputStream zipOutputStream = null;
         try {
             File srcFile = new File(srcPath);
 
@@ -94,8 +101,18 @@ public final class ZipUtil {
                 }
             }
 
-            cos = new CheckedOutputStream(new FileOutputStream(zipFile), new CRC32());
-            zos = new ZipOutputStream(cos);
+            checkedOutputStream = new CheckedOutputStream(new FileOutputStream(zipFile), new CRC32());
+            zipOutputStream = new ZipOutputStream(checkedOutputStream);
+
+            // If with backup metadata, we serialize it and write it into file "kbackup_metadata"
+            ZipEntry metadataEntry = new ZipEntry(BackupMetadata.metadataFileName);
+            zipOutputStream.putNextEntry(metadataEntry);
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            ObjectOutputStream oos = new ObjectOutputStream(baos);
+            oos.writeObject(backupMetadata);
+            oos.close();
+            zipOutputStream.write(baos.toByteArray());
+            zipOutputStream.closeEntry();
 
             //如果只是压缩一个文件，则需要截取该文件的父目录
             String srcRootDir = srcPath;
@@ -106,12 +123,12 @@ public final class ZipUtil {
                 }
             }
             //调用递归压缩方法进行目录或文件压缩
-            zip(srcRootDir, srcFile, zos);
-            zos.flush();
+            zip(srcRootDir, srcFile, zipOutputStream);
+            zipOutputStream.flush();
         } finally {
             try {
-                if (zos != null) {
-                    zos.close();
+                if (zipOutputStream != null) {
+                    zipOutputStream.close();
                 }
             } catch (Exception e) {
                 e.printStackTrace();
@@ -126,7 +143,6 @@ public final class ZipUtil {
      * @param unzipFilePath      解压后的文件保存的路径
      * @param includeZipFileName 解压后的文件保存的路径是否包含压缩文件的文件名。true-包含；false-不包含
      */
-    @SuppressWarnings("unchecked")
     public static void unzip(String zipFilePath, String unzipFilePath, boolean includeZipFileName) throws ZipUtilException, IOException {
         if (zipFilePath.isEmpty() || unzipFilePath.isEmpty()) {
             throw new ZipUtilException("Parameter for unzip() contains null.");
diff --git a/src/main/java/com/keuin/kbackupfabric/worker/BackupWorker.java b/src/main/java/com/keuin/kbackupfabric/worker/BackupWorker.java
index 30fd8b5..0ca9015 100644
--- a/src/main/java/com/keuin/kbackupfabric/worker/BackupWorker.java
+++ b/src/main/java/com/keuin/kbackupfabric/worker/BackupWorker.java
@@ -1,5 +1,7 @@
 package com.keuin.kbackupfabric.worker;
 
+import com.keuin.kbackupfabric.data.BackupMetadata;
+import com.keuin.kbackupfabric.util.PrintUtil;
 import com.keuin.kbackupfabric.util.ZipUtil;
 import com.keuin.kbackupfabric.util.ZipUtilException;
 import com.mojang.brigadier.context.CommandContext;
@@ -14,7 +16,7 @@ import java.util.Map;
 
 import static com.keuin.kbackupfabric.util.BackupFilesystemUtil.*;
 import static com.keuin.kbackupfabric.util.PrintUtil.debug;
-import static com.keuin.kbackupfabric.util.PrintUtil.message;
+import static com.keuin.kbackupfabric.util.PrintUtil.msgInfo;
 
 /**
  * The backup worker
@@ -24,18 +26,21 @@ public final class BackupWorker implements Runnable {
     private final CommandContext<ServerCommandSource> context;
     private final String backupName;
     private final Map<World, Boolean> oldWorldsSavingDisabled;
+    private final BackupMetadata backupMetadata;
+    private final long startTime;
 
-
-    private BackupWorker(CommandContext<ServerCommandSource> context, String backupName, Map<World, Boolean> oldWorldsSavingDisabled) {
+    private BackupWorker(CommandContext<ServerCommandSource> context, String backupName, Map<World, Boolean> oldWorldsSavingDisabled, BackupMetadata backupMetadata, long startTime) {
         this.context = context;
         this.backupName = backupName;
         this.oldWorldsSavingDisabled = oldWorldsSavingDisabled;
+        this.backupMetadata = backupMetadata;
+        this.startTime = startTime;
     }
 
-    public static void invoke(CommandContext<ServerCommandSource> context, String backupName) {
+    public static void invoke(CommandContext<ServerCommandSource> context, String backupName, BackupMetadata backupMetadata) {
         //// Save world, save old autosave configs
 
-        message(context, String.format("Making backup %s, please wait ...", backupName), true);
+        PrintUtil.msgInfo(context, String.format("Making backup %s, please wait ...", backupName), true);
         Map<World, Boolean> oldWorldsSavingDisabled = new HashMap<>(); // old switch stat
 
         // Get server
@@ -54,39 +59,52 @@ public final class BackupWorker implements Runnable {
         server.save(true, true, true);
 
         // Start threaded worker
-        BackupWorker worker = new BackupWorker(context, backupName, oldWorldsSavingDisabled);
+        BackupWorker worker = new BackupWorker(context, backupName, oldWorldsSavingDisabled, backupMetadata, System.currentTimeMillis());
         Thread workerThread = new Thread(worker, "BackupWorker");
         workerThread.start();
     }
 
     @Override
     public void run() {
-        String destPathFolderName = "";
+        String backupSaveDirectory = "";
         MinecraftServer server = context.getSource().getMinecraftServer();
         try {
             //// Do our main backup logic
 
             // Create backup saving directory
-            File destPathFile = getBackupSaveDirectory(server);
-            destPathFolderName = destPathFile.getName();
-            if (!destPathFile.isDirectory() && !destPathFile.mkdir()) {
-                message(context, String.format("Failed to create backup saving directory: %s. Failed to backup.", destPathFolderName));
+            File backupSaveDirectoryFile = getBackupSaveDirectory(server);
+            backupSaveDirectory = backupSaveDirectoryFile.getName();
+            if (!backupSaveDirectoryFile.isDirectory() && !backupSaveDirectoryFile.mkdir()) {
+                msgInfo(context, String.format("Failed to create backup saving directory: %s. Failed to backup.", backupSaveDirectory));
                 return;
             }
 
             // Make zip
             String levelPath = getLevelPath(server);
-            debug(String.format("zip(srcPath=%s, destPath=%s)", levelPath, destPathFile.toString()));
-            ZipUtil.zip(levelPath, destPathFile.toString(), getBackupFileName(backupName));
+            String backupFileName = getBackupFileName(backupName);
+            debug(String.format("zip(srcPath=%s, destPath=%s)", levelPath, backupSaveDirectoryFile.toString()));
+            ZipUtil.makeBackupZip(levelPath, backupSaveDirectoryFile.toString(), backupFileName, backupMetadata);
+            File backupZipFile = new File(backupSaveDirectoryFile, backupFileName);
 
             // Restore old autosave switch stat
             server.getWorlds().forEach(world -> world.savingDisabled = oldWorldsSavingDisabled.getOrDefault(world, true));
 
-            message(context, "Done.", true);
+            // Print finish message: time elapsed and file size
+            long timeEscapedMillis = System.currentTimeMillis() - startTime;
+            msgInfo(context, String.format("Backup finished. (%.2fs)", timeEscapedMillis / 1000.0), true);
+            try {
+                double fileSize = backupZipFile.length() * 1.0 / 1024 / 1024;
+                if (fileSize > 1000)
+                    msgInfo(context, String.format("File size: %.2fGB", fileSize / 1024));
+                else
+                    msgInfo(context, String.format("File size: %.2fMB", fileSize));
+            } catch (SecurityException ignored) {
+            }
+
         } catch (SecurityException e) {
-            message(context, String.format("Failed to create backup saving directory: %s. Failed to backup.", destPathFolderName));
+            msgInfo(context, String.format("Failed to create backup saving directory: %s. Failed to backup.", backupSaveDirectory));
         } catch (IOException | ZipUtilException e) {
-            message(context, "Failed to make zip: " + e.getMessage());
+            msgInfo(context, "Failed to make zip: " + e.getMessage());
         }
     }
 }