优化获取文件后缀名逻辑

framework-common/src/main/java/com/chelvc/framework/common/util/FileUtils.java

@@ -77,7 +77,7 @@ public final class FileUtils {
      * @return 后缀名
      */
     public static String getSuffix(@NonNull String filename) {
-        int separator = filename.indexOf('.');
+        int separator = filename.lastIndexOf('.');
         return separator < 0 ? null : StringUtils.ifEmpty(filename.substring(separator + 1), (String) null);
     }