Java tutorial
/* * Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org) * * 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.traccar.api; import com.fasterxml.jackson.core.JsonProcessingException; import org.eclipse.jetty.websocket.api.Session; import org.eclipse.jetty.websocket.api.WebSocketAdapter; import org.traccar.Context; import org.traccar.database.ConnectionManager; import org.traccar.helper.Log; import org.traccar.model.Device; import org.traccar.model.Event; import org.traccar.model.Position; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Map; public class AsyncSocket extends WebSocketAdapter implements ConnectionManager.UpdateListener { private static final String KEY_DEVICES = "devices"; private static final String KEY_POSITIONS = "positions"; private static final String KEY_EVENTS = "events"; private long userId; public AsyncSocket(long userId) { this.userId = userId; } @Override public void onWebSocketConnect(Session session) { super.onWebSocketConnect(session); Map<String, Collection<?>> data = new HashMap<>(); data.put(KEY_POSITIONS, Context.getDeviceManager().getInitialState(userId)); sendData(data); Context.getConnectionManager().addListener(userId, this); } @Override public void onWebSocketClose(int statusCode, String reason) { super.onWebSocketClose(statusCode, reason); Context.getConnectionManager().removeListener(userId, this); } @Override public void onUpdateDevice(Device device) { Map<String, Collection<?>> data = new HashMap<>(); data.put(KEY_DEVICES, Collections.singletonList(device)); sendData(data); } @Override public void onUpdatePosition(Position position) { Map<String, Collection<?>> data = new HashMap<>(); data.put(KEY_POSITIONS, Collections.singletonList(position)); sendData(data); } @Override public void onUpdateEvent(Event event) { Map<String, Collection<?>> data = new HashMap<>(); data.put(KEY_EVENTS, Collections.singletonList(event)); sendData(data); } private void sendData(Map<String, Collection<?>> data) { if (!data.isEmpty() && isConnected()) { try { getRemote().sendString(Context.getObjectMapper().writeValueAsString(data), null); } catch (JsonProcessingException e) { Log.warning(e); } } } }