diff --git a/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/book/service/impl/BookCarServiceImpl.java b/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/book/service/impl/BookCarServiceImpl.java
index 830ed19..cfbcb96 100644
--- a/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/book/service/impl/BookCarServiceImpl.java
+++ b/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/book/service/impl/BookCarServiceImpl.java
@@ -120,18 +120,4 @@ public class BookCarServiceImpl implements BookCarService {
         List<DevInfoVo> bookCarDetails = bookCarMapper.getBookCarDetails(devInfo);
         return AjaxResult.success(bookCarDetails);
     }
-
-    public static String generateOrderNumber() {
-        // 获取当前时间戳（毫秒级）
-        long timestamp = System.currentTimeMillis();
-        // 生成一个 4 位的随机数（可以根据需要修改长度）
-        int randomPart = (int) (Math.random() * 10000);
-        // 组合时间戳和随机数
-        return timestamp + String.format("%04d", randomPart);
-    }
-
-    public static void main(String[] args) {
-        System.out.println("Order Number: " + generateOrderNumber());
-    }
-
 }
diff --git a/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/common/utils/StringUtil.java b/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/common/utils/StringUtil.java
new file mode 100644
index 0000000..5e910fe
--- /dev/null
+++ b/bonus-modules/bonus-material-mall/src/main/java/com/bonus/material/common/utils/StringUtil.java
@@ -0,0 +1,17 @@
+package com.bonus.material.common.utils;
+
+public class StringUtil {
+
+    /**
+     * 生成订单编号
+     * @return
+     */
+    public String generateOrderNumber() {
+        // 获取当前时间戳（毫秒级）
+        long timestamp = System.currentTimeMillis();
+        // 生成一个 4 位的随机数（可以根据需要修改长度）
+        int randomPart = (int) (Math.random() * 10000);
+        // 组合时间戳和随机数
+        return timestamp + String.format("%04d", randomPart);
+    }
+}