增加websocket

src/main/java/com/onekeycall/videotablet/service/DeviceSnService.java

@@ -0,0 +1,20 @@
+package com.onekeycall.videotablet.service;
+
+import com.onekeycall.videotablet.entity.DeviceInfo;
+import com.onekeycall.videotablet.repository.DeviceSnRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class DeviceSnService {
+    private final DeviceSnRepository deviceSnRepository;
+
+    @Autowired
+    public DeviceSnService(DeviceSnRepository deviceSnRepository) {
+        this.deviceSnRepository = deviceSnRepository;
+    }
+
+    public DeviceInfo findBySn(String sn) {
+        return deviceSnRepository.findBySn(sn);
+    }
+}