Java tutorial
/** * Copyright 2016-2018 The Thingsboard Authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.thingsboard.rule.engine.util; import com.google.common.util.concurrent.AsyncFunction; import com.google.common.util.concurrent.Futures; import com.google.common.util.concurrent.ListenableFuture; import org.apache.commons.collections.CollectionUtils; import org.thingsboard.rule.engine.api.TbContext; import org.thingsboard.rule.engine.data.DeviceRelationsQuery; import org.thingsboard.server.common.data.Device; import org.thingsboard.server.common.data.device.DeviceSearchQuery; import org.thingsboard.server.common.data.id.DeviceId; import org.thingsboard.server.common.data.id.EntityId; import org.thingsboard.server.common.data.relation.RelationsSearchParameters; import org.thingsboard.server.dao.device.DeviceService; import java.util.List; public class EntitiesRelatedDeviceIdAsyncLoader { public static ListenableFuture<DeviceId> findDeviceAsync(TbContext ctx, EntityId originator, DeviceRelationsQuery deviceRelationsQuery) { DeviceService deviceService = ctx.getDeviceService(); DeviceSearchQuery query = buildQuery(originator, deviceRelationsQuery); ListenableFuture<List<Device>> asyncDevices = deviceService.findDevicesByQuery(ctx.getTenantId(), query); return Futures.transformAsync(asyncDevices, d -> CollectionUtils.isNotEmpty(d) ? Futures.immediateFuture(d.get(0).getId()) : Futures.immediateFuture(null)); } private static DeviceSearchQuery buildQuery(EntityId originator, DeviceRelationsQuery deviceRelationsQuery) { DeviceSearchQuery query = new DeviceSearchQuery(); RelationsSearchParameters parameters = new RelationsSearchParameters(originator, deviceRelationsQuery.getDirection(), deviceRelationsQuery.getMaxLevel()); query.setParameters(parameters); query.setRelationType(deviceRelationsQuery.getRelationType()); query.setDeviceTypes(deviceRelationsQuery.getDeviceTypes()); return query; } }