feat: 新增编码预览功能

- 后端新增 /rpc-api/base/code-gen/preview 接口
- SequenceAllocator.preview 查询序号但不消耗
- 前端操作列新增预览按钮，弹窗展示下一个编码

nl-module-base/nl-module-base-api/src/main/java/cn/code/nl/module/base/api/codegen/CodeGenApi.java

@@ -9,6 +9,8 @@ import jakarta.validation.Valid;
 import org.springframework.cloud.openfeign.FeignClient;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 
 /**
  * RPC 服务 - 编码生成
@@ -31,4 +33,8 @@ public interface CodeGenApi {
     @Operation(summary = "生成编码")
     CommonResult<String> generate(@Valid @RequestBody CodeGenerateReqDTO reqDTO);
 
+    @GetMapping(PREFIX + "/preview")
+    @Operation(summary = "预览下一个编码（不消耗序号）")
+    CommonResult<String> preview(@RequestParam("ruleCode") String ruleCode);
+
 }

nl-module-base/nl-module-base-server/src/main/java/cn/code/nl/module/base/controller/api/CodeGenController.java

@@ -8,9 +8,11 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.Resource;
 import jakarta.validation.Valid;
 import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import static cn.code.nl.framework.common.pojo.CommonResult.success;
@@ -39,4 +41,11 @@ public class CodeGenController {
         return success(code);
     }
 
+    @GetMapping("/preview")
+    @Operation(summary = "预览下一个编码（不消耗序号）")
+    public CommonResult<String> preview(@RequestParam("ruleCode") String ruleCode) {
+        String code = codeGenService.preview(ruleCode);
+        return success(code);
+    }
+
 }

nl-module-base/nl-module-base-server/src/main/java/cn/code/nl/module/base/service/codegen/CodeGenService.java

@@ -15,4 +15,12 @@ public interface CodeGenService {
      */
     String generate(String ruleCode);
 
+    /**
+     * 预览下一个编码（不消耗序号）
+     *
+     * @param ruleCode 规则编码
+     * @return 预览的编码
+     */
+    String preview(String ruleCode);
+
 }

nl-module-base/nl-module-base-server/src/main/java/cn/code/nl/module/base/service/codegen/CodeGenServiceImpl.java

@@ -54,6 +54,26 @@ public class CodeGenServiceImpl implements CodeGenService {
         return postProcess(sb.toString(), rule);
     }
 
+    @Override
+    public String preview(String ruleCode) {
+        // 1. 获取规则配置
+        CodeRuleDO rule = codeRuleService.getRuleByCode(ruleCode);
+
+        // 2. 遍历分段，SEQUENCE 段用 preview（不消耗序号）
+        List<SegmentConfig> segments = rule.getSegmentConfig();
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < segments.size(); i++) {
+            String segmentValue = buildPreviewSegment(rule, segments.get(i));
+            sb.append(segmentValue);
+            if (i < segments.size() - 1 && StrUtil.isNotBlank(rule.getSeparator())) {
+                sb.append(rule.getSeparator());
+            }
+        }
+
+        // 3. 后处理
+        return postProcess(sb.toString(), rule);
+    }
+
     /**
      * 根据段类型分发处理，生成段值
      */
@@ -66,6 +86,18 @@ public class CodeGenServiceImpl implements CodeGenService {
         };
     }
 
+    /**
+     * 预览模式分发（SEQUENCE 段不消耗序号）
+     */
+    private String buildPreviewSegment(CodeRuleDO rule, SegmentConfig segment) {
+        return switch (segment.getType()) {
+            case "PREFIX" -> buildPrefixSegment(segment);
+            case "DATE" -> buildDateSegment(segment);
+            case "SEQUENCE" -> sequenceAllocator.preview(rule.getId(), segment);
+            default -> throw new IllegalArgumentException("不支持的段类型: " + segment.getType());
+        };
+    }
+
     /**
      * 生成固定前缀段
      */

nl-module-base/nl-module-base-server/src/main/java/cn/code/nl/module/base/service/codegen/SequenceAllocator.java

@@ -189,4 +189,19 @@ public class SequenceAllocator {
         return paddingChar.repeat(paddingLen - raw.length()) + raw;
     }
 
+    /**
+     * 预览下一个序号（不实际分配，不更新数据库）
+     *
+     * @param ruleId  规则ID
+     * @param segment 序号段配置
+     * @return 格式化后的序号字符串
+     */
+    public String preview(Long ruleId, SegmentConfig segment) {
+        String resetKey = buildResetKey(segment.getResetBy());
+        CodeSequenceDO seq = codeSequenceMapper.selectByRuleIdAndResetKey(ruleId, resetKey);
+        Long startAt = segment.getStartAt() != null ? segment.getStartAt() : 1L;
+        long nextValue = (seq != null) ? seq.getCurrentValue() + 1 : startAt;
+        return formatSequence(nextValue, segment);
+    }
+
 }

nl-ui/nl-ui-admin-vben/yudao-ui-admin-vben/apps/web-antdv-next/src/api/base/codegen/index.ts

@@ -79,3 +79,11 @@ export async function updateCodeRule(data: BaseCodeRuleApi.CodeRule) {
 export async function deleteCodeRule(id: number) {
   return requestClient.delete(`/base/code-rule/delete?id=${id}`);
 }
+
+/** 预览下一个编码（不消耗序号） */
+export async function previewCode(ruleCode: string) {
+  return requestClient.get<string>(
+    '/rpc-api/base/code-gen/preview',
+    { params: { ruleCode } },
+  );
+}

nl-ui/nl-ui-admin-vben/yudao-ui-admin-vben/apps/web-antdv-next/src/views/base/codegen/index.vue

@@ -7,10 +7,10 @@ import { ref } from 'vue';
 import { confirm, Page, useVbenModal } from '@vben/common-ui';
 import { isEmpty } from '@vben/utils';
 
-import { message } from 'antdv-next';
+import { Modal, message } from 'antdv-next';
 
 import { ACTION_ICON, TableAction, useVbenVxeGrid } from '#/adapter/vxe-table';
-import { deleteCodeRule, getCodeRulePage } from '#/api/base/codegen';
+import { deleteCodeRule, getCodeRulePage, previewCode } from '#/api/base/codegen';
 import { $t } from '#/locales';
 
 import { useGridColumns, useGridFormSchema } from './data';
@@ -51,7 +51,7 @@ async function handleDelete(row: BaseCodeRuleApi.CodeRule) {
   }
 }
 
-/** 批量删除编码规则 */
+/** 批量删除 */
 async function handleDeleteBatch() {
   await confirm($t('ui.actionMessage.deleteBatchConfirm'));
   const hideLoading = message.loading({
@@ -70,6 +70,25 @@ async function handleDeleteBatch() {
   }
 }
 
+/** 预览下一个编码 */
+const previewVisible = ref(false);
+const previewLoading = ref(false);
+const previewCodeValue = ref('');
+const previewTitle = ref('');
+async function handlePreview(row: BaseCodeRuleApi.CodeRule) {
+  previewTitle.value = row.ruleName;
+  previewLoading.value = true;
+  previewVisible.value = true;
+  try {
+    const result = await previewCode(row.ruleCode);
+    previewCodeValue.value = result ?? '';
+  } catch {
+    previewCodeValue.value = '预览失败';
+  } finally {
+    previewLoading.value = false;
+  }
+}
+
 const checkedIds = ref<number[]>([]);
 function handleRowCheckboxChange({
   records,
@@ -145,6 +164,13 @@ const [Grid, gridApi] = useVbenVxeGrid({
       <template #actions="{ row }">
         <TableAction
           :actions="[
+            {
+              label: '预览',
+              type: 'link',
+              icon: ACTION_ICON.SEARCH,
+              auth: ['base:code-rule:query'],
+              onClick: handlePreview.bind(null, row),
+            },
             {
               label: $t('common.edit'),
               type: 'link',
@@ -167,5 +193,23 @@ const [Grid, gridApi] = useVbenVxeGrid({
         />
       </template>
     </Grid>
+
+    <!-- 预览弹窗 -->
+    <Modal
+      v-model:open="previewVisible"
+      title="编码预览"
+      :footer="null"
+      :width="500"
+    >
+      <div v-if="previewLoading" class="py-8 text-center text-gray-400">
+        加载中...
+      </div>
+      <div v-else class="py-4">
+        <p class="mb-2 text-sm text-gray-500">规则：{{ previewTitle }}</p>
+        <p class="text-2xl font-mono font-bold tracking-wider text-blue-600">
+          {{ previewCodeValue }}
+        </p>
+      </div>
+    </Modal>
   </Page>
 </template>