update oss-api FileUtil

oss-api/src/main/java/cn/reghao/oss/api/util/FileUtil.java

@@ -5,6 +5,16 @@ package cn.reghao.oss.api.util;
  * @date 2026-04-28 16:07:27
  */
 public class FileUtil {
+    /**
+     * 从文件名中提取后缀名
+     *
+     * test.jpg 返回 jpg
+     * test 返回 ""
+     *
+     * @param
+     * @return
+     * @date 2026-06-05 17:59:18
+     */
     public static String getSuffix(String filename) {
         if (filename == null) {
             return "";
@@ -17,11 +27,11 @@ public class FileUtil {
     public static String getSuffixByMime(String mime) {
         String suffix = "dat";
         if (mime.startsWith("image")) {
-            suffix = ".jpg";
+            suffix = "jpg";
         } else if (mime.startsWith("video")) {
-            suffix = ".mp4";
+            suffix = "mp4";
         } else if (mime.startsWith("audio")) {
-            suffix = ".mp3";
+            suffix = "mp3";
         }
 
         return suffix;