feat(printer):优化订单打印纸张尺寸获取逻辑

- 引入Redis缓存存储打印纸张尺寸信息
- 优先从Redis中获取纸张尺寸，减少数据库查询
- 在创建订单时将打印机偏好纸张存入Redis，有效期60秒
- 修复打印机对象作用域问题，避免空指针异常
- 统一打印机状态校验逻辑，提高代码可读性

src/main/java/com/ycwl/basic/service/printer/impl/PrinterServiceImpl.java

@@ -483,6 +483,7 @@ public class PrinterServiceImpl implements PrinterService {
 
     @Override
     public Map<String, Object> createOrder(Long memberId, Long scenicId, Integer printerId, Long faceId) {
+        PrinterEntity printer = null;
         if (printerId == null) {
             List<PrinterResp> printerList = printerMapper.listByScenicId(scenicId);
             if (printerList.size() != 1) {
@@ -491,16 +492,16 @@ public class PrinterServiceImpl implements PrinterService {
                 printerId = printerList.getFirst().getId();
             }
         } else {
-            PrinterEntity printer = printerMapper.getById(printerId);
-            if (printer == null) {
-                throw new BaseException("打印机不存在");
-            }
-            if (printer.getStatus() != 1) {
-                throw new BaseException("打印机已停用");
-            }
-            if (!printer.getScenicId().equals(scenicId)) {
-                throw new BaseException("打印机不属于该景区");
-            }
+            printer = printerMapper.getById(printerId);
+        }
+        if (printer == null) {
+            throw new BaseException("打印机不存在");
+        }
+        if (printer.getStatus() != 1) {
+            throw new BaseException("打印机已停用");
+        }
+        if (!printer.getScenicId().equals(scenicId)) {
+            throw new BaseException("打印机不属于该景区");
         }
         // 验证照片数量
         List<MemberPrintResp> userPhotoList = getUserPhotoList(memberId, scenicId, faceId);
@@ -511,6 +512,7 @@ public class PrinterServiceImpl implements PrinterService {
 
         OrderEntity order = new OrderEntity();
         Long orderId = SnowFlakeUtil.getLongId();
+        redisTemplate.opsForValue().set("printer_size:"+orderId, printer.getPreferPaper(), 60, TimeUnit.SECONDS);
         order.setId(orderId);
         order.setMemberId(memberId);
         order.setFaceId(faceId);