diff --git a/src/main.java b/src/main.java
index 78d8817..223723f 100644
--- a/src/main.java
+++ b/src/main.java
@@ -1,21 +1,36 @@
 import mobimeta.*;
 
 import java.io.File;
+import java.util.Arrays;
+import java.util.Iterator;
 import java.util.List;
 
 class Main {
     static String splitLine = "================================================================";
 
-    public static void showMeta(File file) {
-        System.out.println(splitLine);
-        System.out.println("File name: " + file.getName());
-        MobiMeta meta;
+    private static MobiMeta readFile(File file) {
+        MobiMeta meta = null;
         try {
             meta = new MobiMeta(file);
         } catch (MobiMetaException err) {
-            System.err.println("Error: " + err.getMessage());
-            return;
+            System.err.println("Error reading file: " + err.getMessage());
+            System.exit(1);
         }
+        return meta;
+    }
+
+    private static void saveFile(MobiMeta meta, File file) {
+        try {
+            meta.saveToNewFile(file);
+        } catch (MobiMetaException err) {
+            System.err.println("Error saving file: " + err.getMessage());
+        }
+    }
+
+    private static void showMeta(File file) {
+        System.out.println(splitLine);
+        System.out.println("File name: " + file.getName());
+        MobiMeta meta = readFile(file);
         String encoding = meta.getCharacterEncoding();
         List<EXTHRecord> exthList = meta.getEXTHRecords();
         System.out.println("Book name: " + meta.getFullName());
@@ -48,13 +63,35 @@ class Main {
         System.out.println(splitLine);
     }
 
+    private static void setBookName(MobiMeta meta, String name) {
+        String encoding = meta.getCharacterEncoding();
+        List<EXTHRecord> exthList = meta.getEXTHRecords();
+        boolean flag = false;
+        for (EXTHRecord rec : exthList) {
+            if (rec.getRecordType() == 503) {
+                rec.setData(name, encoding);
+                flag = true;
+            }
+        }
+        if (!flag) { // without updated title
+            exthList.add(new EXTHRecord(503, name, encoding));
+        }
+        meta.setFullName(name);
+        meta.setEXTHRecords();
+    }
+
     public static void main(String[] args) {
 
         String testFile = "XXRS.azw3";
 
         File target = new File(testFile);
-
         showMeta(target);
 
+//        MobiMeta meta = readFile(target);
+//        setBookName(meta, "生若栩栩");
+//        showMeta(target);
+
+//        saveFile(meta, new File("XXRS_new.azw3"));
+
     }
 }