Java tutorial
/* * Copyright 2016 The Lannister Project * * 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 net.anyflow.lannister.packetreceiver; import java.util.Collection; import java.util.Date; import java.util.List; import java.util.Map; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.mqtt.MqttQoS; import io.netty.handler.codec.mqtt.MqttSubscribeMessage; import io.netty.handler.codec.mqtt.MqttTopicSubscription; import io.netty.util.CharsetUtil; import net.anyflow.lannister.AbnormalDisconnectEventArgs; import net.anyflow.lannister.Settings; import net.anyflow.lannister.Statistics; import net.anyflow.lannister.message.Message; import net.anyflow.lannister.message.MessageFactory; import net.anyflow.lannister.plugin.DefaultSubscribeEventListener; import net.anyflow.lannister.plugin.DisconnectEventListener; import net.anyflow.lannister.plugin.ITopicSubscription; import net.anyflow.lannister.plugin.Plugins; import net.anyflow.lannister.plugin.SubscribeEventArgs; import net.anyflow.lannister.plugin.SubscribeEventListener; import net.anyflow.lannister.session.Session; import net.anyflow.lannister.topic.TopicMatcher; import net.anyflow.lannister.topic.TopicSubscription; public class SubscribeReceiver extends SimpleChannelInboundHandler<MqttSubscribeMessage> { private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(SubscribeReceiver.class); @Override protected void channelRead0(ChannelHandlerContext ctx, MqttSubscribeMessage msg) throws Exception { logger.debug("packet incoming [message={}]", msg.toString()); Session session = Session.NEXUS.get(ctx.channel().id()); if (session == null) { logger.error("None exist session message [message={}]", msg.toString()); ctx.channel().disconnect().addListener(ChannelFutureListener.CLOSE).addListener(fs -> // [MQTT-4.8.0-1] Plugins.SELF.get(DisconnectEventListener.class).disconnected(new AbnormalDisconnectEventArgs())); return; } session.setLastIncomingTime(new Date()); List<MqttTopicSubscription> topicSubs = msg.payload().topicSubscriptions(); if (topicSubs == null || topicSubs.isEmpty()) { session.dispose(true); // [MQTT-4.8.0-1] return; } // TODO multiple sub checking (granted QoS) Map.Entry<List<Integer>, Map<String, TopicSubscription>> returns = generateReturns(topicSubs); List<Integer> grantedQoss = returns.getKey(); Map<String, TopicSubscription> topicSubscriptions = returns.getValue(); if (!executePlugins(session, topicSubscriptions.values())) { return; } session.topicSubscriptions().putAll(topicSubscriptions); session.send(MessageFactory.suback(msg.variableHeader().messageId(), grantedQoss)); // [MQTT-2.3.1-7],[MQTT-2.3.1-7],[MQTT-3.8.4-1],[MQTT-3.8.4-2] sendRetainedMessage(session, topicSubscriptions); publishStatic$Sys(session, topicSubscriptions.values()); // TODO [MQTT-3.3.1-7] } private void sendRetainedMessage(Session session, Map<String, TopicSubscription> topicSubscriptions) { session.topics(topicSubscriptions.values()).forEach(topic -> { if (topic.retainedMessage() == null) { return; } topic.putMessage(topic.retainedMessage().publisherId(), topic.retainedMessage()); session.sendPublish(topic, topic.retainedMessage()); // [MQTT-3.3.1-6],[MQTT-3.3.1-8] }); } private Map.Entry<List<Integer>, Map<String, TopicSubscription>> generateReturns( List<MqttTopicSubscription> topicSubs) { List<Integer> grantedQoss = Lists.newArrayList(); Map<String, TopicSubscription> topicSubscriptions = Maps.newHashMap(); topicSubs.stream().forEach(topicSub -> { if (TopicMatcher.isValid(topicSub.topicName(), true)) { TopicSubscription topicSubscription = new TopicSubscription(topicSub.topicName(), topicSub.qualityOfService()); grantedQoss.add(topicSubscription.qos().value()); topicSubscriptions.put(topicSubscription.topicFilter(), topicSubscription); } else { grantedQoss.add(MqttQoS.FAILURE.value()); } }); return new Map.Entry<List<Integer>, Map<String, TopicSubscription>>() { @Override public List<Integer> getKey() { return grantedQoss; } @Override public Map<String, TopicSubscription> getValue() { return topicSubscriptions; } @Override public Map<String, TopicSubscription> setValue(Map<String, TopicSubscription> value) { return null; // Should not be called } }; } private boolean executePlugins(Session session, Collection<TopicSubscription> topicSubscriptions) { SubscribeEventArgs args = new SubscribeEventArgs() { @Override public List<ITopicSubscription> topicSubscriptions() { return Lists.newArrayList(topicSubscriptions); } @Override public String clientId() { return session.clientId(); } @Override public boolean cleanSession() { return session.cleanSession(); } }; if (!DefaultSubscribeEventListener.SHARED.allowSubscribe(args)) { session.dispose(true); return false; } if (!Plugins.SELF.get(SubscribeEventListener.class).allowSubscribe(args)) { session.dispose(true); return false; } return true; } private void publishStatic$Sys(Session session, Collection<TopicSubscription> topicSubscriptions) { String requesterId = Settings.SELF.getProperty("lannister.broker.id", "lannister_broker_id"); topicSubscriptions.stream().forEach(ts -> { Statistics.$SYS_STATIC_TOPICS.stream().forEach(t -> { if (!TopicMatcher.match(ts.topicFilter(), t)) { return; } byte[] msg = Statistics.SELF.getStatic(t).getBytes(CharsetUtil.UTF_8); session.send(MessageFactory .publish(new Message(-1, t, requesterId, msg, MqttQoS.AT_MOST_ONCE, false), false)) .addListener(f -> { Statistics.SELF.add(Statistics.Criterion.MESSAGES_PUBLISH_SENT, 1); }); }); }); } }