diff --git a/ruoyi-oa/src/main/java/com/ruoyi/oa/controller/CodeGeneratorController.java b/ruoyi-oa/src/main/java/com/ruoyi/oa/controller/CodeGeneratorController.java
index ba30885..1b8c4b5 100644
--- a/ruoyi-oa/src/main/java/com/ruoyi/oa/controller/CodeGeneratorController.java
+++ b/ruoyi-oa/src/main/java/com/ruoyi/oa/controller/CodeGeneratorController.java
@@ -19,4 +19,10 @@ public class CodeGeneratorController {
     public String genCode(@PathVariable String prefix) {
         return gen.nextCode(prefix);
     }
+
+
+   @GetMapping("/max/{prefix}")
+    public Long maxCode(@PathVariable String prefix) {
+        return gen.maxCode(prefix);
+    }
 }
diff --git a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/CodeGeneratorService.java b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/CodeGeneratorService.java
index a652eef..f4af6d5 100644
--- a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/CodeGeneratorService.java
+++ b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/CodeGeneratorService.java
@@ -3,4 +3,6 @@ package com.ruoyi.oa.service;
 public interface CodeGeneratorService {
 
     String nextCode(String prefix) ;
+
+    Long maxCode(String prefix);
 }
diff --git a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/CodeGeneratorServiceImpl.java b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/CodeGeneratorServiceImpl.java
index 5a56e7b..369718f 100644
--- a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/CodeGeneratorServiceImpl.java
+++ b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/CodeGeneratorServiceImpl.java
@@ -23,4 +23,14 @@ public class CodeGeneratorServiceImpl implements CodeGeneratorService {
         String padded = String.format("%07d", num);
         return prefix + "-" + padded;   // e.g. TH-0000001
     }
+
+
+
+    @Transactional(rollbackFor = Exception.class)
+    @Override
+    public Long maxCode(String prefix) {
+        mapper.upsertAndIncr(prefix);   // 原子插/更
+        long num = mapper.getLastSeq(); // 拿到新的序号
+        return num-1L;   //
+    }
 }