增加websocket获取设备当前状态

jetlinks-manager/device-manager/src/main/java/org/jetlinks/community/device/message/DeviceCurrentStateSubscriptionProvider.java

@@ -0,0 +1,57 @@
+package org.jetlinks.community.device.message;
+
+import lombok.AllArgsConstructor;
+import org.jetlinks.community.device.entity.DeviceInstanceEntity;
+import org.jetlinks.community.device.service.LocalDeviceInstanceService;
+import org.jetlinks.community.gateway.external.SubscribeRequest;
+import org.jetlinks.community.gateway.external.SubscriptionProvider;
+import org.springframework.stereotype.Component;
+import reactor.core.publisher.Flux;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+@Component
+@AllArgsConstructor
+public class DeviceCurrentStateSubscriptionProvider implements SubscriptionProvider {
+
+    private final LocalDeviceInstanceService instanceService;
+
+    @Override
+    public String id() {
+        return "device-state-subscriber";
+    }
+
+    @Override
+    public String name() {
+        return "设备当前状态消息";
+    }
+
+    @Override
+    public String[] getTopicPattern() {
+        return new String[]{
+            "/device-current-state"
+        };
+    }
+
+    @Override
+    @SuppressWarnings("all")
+    public Flux<Map<String, Object>> subscribe(SubscribeRequest request) {
+        List<String> deviceId = request.get("deviceId")
+            .map(List.class::cast)
+            .orElseThrow(() -> new IllegalArgumentException("deviceId不能为空"));
+
+        return Flux
+            .fromIterable(deviceId)
+            .buffer(200)
+            .concatMap(buf -> {
+                return instanceService.createQuery()
+                    .select(DeviceInstanceEntity::getId, DeviceInstanceEntity::getState)
+                    .in(DeviceInstanceEntity::getId, buf)
+                    .fetch();
+            })
+            .map(instance -> Collections.singletonMap(instance.getId(), instance.getState().name()));
+
+    }
+}