物联网之对接MQTT最佳实践
小伙伴们，你们好呀，我是老寇，跟我一起学习对接MQTT
安装EMQX
采用docker-compose一键式启动！！！
还没有安装docker朋友，参考文章下面两篇文章
使用 emqx 5.4.1，按照老夫的教程来，请不要改版本号！！！
使用 emqx 5.4.1，按照老夫的教程来，请不要改版本号！！！
使用 emqx 5.4.1，按照老夫的教程来，请不要改版本号！！！
services:
emqx:
image: emqx/emqx:5.4.1
container_name: emqx
# 保持容器在没有守护程序的情况下运行
tty: true
restart: always
privileged: true
ports:
- "1883:1883"
- "8083:8083"
- "8883:8883"
- "18083:18083"
environment:
- TZ=Asia/Shanghai
volumes:
# 挂载数据存储
- ./emqx/data:/opt/emqx/data
# 挂载日志文件
- ./emqx/log:/opt/emqx/log
networks:
- laokou_network
networks:
laokou_network:
driver: bridge
访问 http://127.0.0.1:18083 设置密码
EMQX MQTT【摘抄自官方文档】
MQTT 是物联网 (IoT) 的 OASIS 标准消息传递协议。它被设计为一种极轻量的发布/订阅消息传输协议，非常适合以较小的代码占用空间和极低的网络带宽连接远程设备。MQTT 目前广泛应用于汽车、制造、电信、石油和天然气等众多行业。
EMQX 完全兼容 MQTT 5.0 和 3.x，本节将介绍 MQTT 相关功能的基本配置项，包括基本 MQTT 设置、订阅设置、会话设置、强制关闭设置和强制垃圾回收设置等
客户端对接
本文章采用三种客户端对接
| 维度 | Paho | Hivemq-MQTT-Client | Vert.x MQTT Client |
|---|---|---|---|
| 协议支持 | MQTT 3.1.1（5.0 实验性） | MQTT 5.0 完整支持 | MQTT 5.0（较新版本） |
| 性能 | 中（同步模式） | 高（异步非阻塞） | 极高（响应式架构） |
| 依赖复杂度 | 低 | 中（仅 Netty） | 高（需 Vert.x 生态） |
| 社区资源 | 丰富 | 较少 | 中等 |
| 适用场景 | 传统 IoT、跨语言项目 | 企业级 MQTT 5.0、高吞吐 | 响应式系统、高并发微服务 |
Paho【不推荐，连接不稳定】
引入依赖
<dependencies>
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.mqttv5.client</artifactId>
<version>1.2.5</version>
</dependency>
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
<version>1.2.5</version>
</dependency>
</dependencies>
项目集成
PahoProperties
/**
* @author laokou
*/
@Data
public class PahoProperties {
private boolean auth = true;
private String username = "emqx";
private String password = "laokou123";
private String host = "127.0.0.1";
private int port = 1883;
private String clientId;
private int subscribeQos = 1;
private int publishQos = 0;
private int willQos = 1;
private int connectionTimeout = 60;
private boolean manualAcks = false;
// @formatter:off
/**
* 控制是否创建新会话（true=新建，false=复用历史会话）. clearStart=true => Broker 会在连接断开后立即清除所有会话信息.
* clearStart=false => Broker 会在连接断开后保存会话信息，并在重新连接后复用会话信息.
* <a href="https://github.com/hivemq/hivemq-mqtt-client/issues/627">...</a>
*/
// @formatter:on
private boolean clearStart = false;
private int receiveMaximum = 10000;
private int maximumPacketSize = 10000;
// @formatter:off
/**
* 默认会话保留一天.
* 最大值，4294967295L，会话过期时间【永不过期，单位秒】.
* 定义客户端断开后会话保留的时间（仅在 Clean Session = false 时生效）.
*/
private long sessionExpiryInterval = 86400L;
// @formatter:on
/**
* 心跳包每隔60秒发一次.
*/
private int keepAliveInterval = 60;
private boolean automaticReconnect = true;
private Set<String> topics = new HashSet<>(0);
}
PahoMqttClientMessageCallbackV5
/**
* @author laokou
*/
@Slf4j
@RequiredArgsConstructor
public class PahoMqttClientMessageCallbackV5 implements MqttCallback {
private final List<MessageHandler> messageHandlers;
@Override
public void disconnected(MqttDisconnectResponse disconnectResponse) {
log.error("【Paho-V5】 => MQTT关闭连接");
}
@Override
public void mqttErrorOccurred(MqttException ex) {
log.error("【Paho-V5】 => MQTT报错，错误信息：{}", ex.getMessage());
}
@Override
public void messageArrived(String topic, MqttMessage message) {
for (MessageHandler messageHandler : messageHandlers) {
if (messageHandler.isSubscribe(topic)) {
log.info("【Paho-V5】 => MQTT接收到消息，Topic：{}", topic);
messageHandler.handle(new org.laokou.sample.mqtt.handler.MqttMessage(message.getPayload(), topic));
}
}
}
@Override
public void deliveryComplete(IMqttToken token) {
log.info("【Paho-V5】 => MQTT消息发送成功，消息ID：{}", token.getMessageId());
}
@Override
public void connectComplete(boolean reconnect, String uri) {
if (reconnect) {
log.info("【Paho-V5】 => MQTT重连成功，URI：{}", uri);
}
else {
log.info("【Paho-V5】 => MQTT建立连接，URI：{}", uri);
}
}
@Override
public void authPacketArrived(int reasonCode, MqttProperties properties) {
log.info("【Paho-V5】 => 接收到身份验证数据包：{}", reasonCode);
}
}
PahoV5MqttClientTest
/**
* @author laokou
*/
@SpringBootTest
@RequiredArgsConstructor
@TestConstructor(autowireMode = TestConstructor.AutowireMode.ALL)
class PahoV5MqttClientTest {
private final List<MessageHandler> messageHandlers;
@Test
void testMqttClient() throws InterruptedException {
ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(16);
PahoProperties pahoProperties = new PahoProperties();
pahoProperties.setClientId("test-client-3");
pahoProperties.setTopics(Set.of("/test-topic-3/#"));
PahoMqttClientV5 pahoMqttClientV5 = new PahoMqttClientV5(pahoProperties, messageHandlers, scheduledExecutorService);
pahoMqttClientV5.open();
Thread.sleep(1000);
pahoMqttClientV5.publish("/test-topic-3/789", "Hello World789".getBytes());
}
}
PahoMqttClientMessageCallbackV3
/**
* @author laokou
*/
@Slf4j
@RequiredArgsConstructor
public class PahoMqttClientMessageCallbackV3 implements MqttCallback {
private final List<MessageHandler> messageHandlers;
@Override
public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
log.info("【Paho-V3】 => MQTT消息发送成功，消息ID：{}", iMqttDeliveryToken.getMessageId());
}
@Override
public void connectionLost(Throwable throwable) {
log.error("【Paho-V3】 => MQTT关闭连接");
}
@Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
for (MessageHandler messageHandler : messageHandlers) {
if (messageHandler.isSubscribe(topic)) {
log.info("【Paho-V3】 => MQTT接收到消息，Topic：{}", topic);
messageHandler.handle(new org.laokou.sample.mqtt.handler.MqttMessage(message.getPayload(), topic));
}
}
}
}
PahoV3MqttClientTest
/**
* @author laokou
*/
@SpringBootTest
@RequiredArgsConstructor
@TestConstructor(autowireMode = TestConstructor.AutowireMode.ALL)
class PahoV3MqttClientTest {
private final List<MessageHandler> messageHandlers;
@Test
void testMqttClient() throws InterruptedException {
ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(16);
PahoProperties pahoProperties2 = new PahoProperties();
pahoProperties2.setClientId("test-client-4");
pahoProperties2.setTopics(Set.of("/test-topic-4/#"));
PahoMqttClientV3 pahoMqttClientV3 = new PahoMqttClientV3(pahoProperties2, messageHandlers, scheduledExecutorService);
pahoMqttClientV3.open();
Thread.sleep(1000);
pahoMqttClientV3.publish("/test-topic-4/000", "Hello World000".getBytes());
}
}
Hivemq-MQTT-Client【不推荐】
注意：订阅一段时间收不到数据，标准mqtt5.0协议，不兼容emqx broker mqtt5.0
引入依赖
<dependencies>
<dependency>
<groupId>com.hivemq</groupId>
<artifactId>hivemq-mqtt-client-reactor</artifactId>
<version>1.3.5</version>
</dependency>
<dependency>
<groupId>com.hivemq</groupId>
<artifactId>hivemq-mqtt-client-epoll</artifactId>
<version>1.3.5</version>
<type>pom</type>
</dependency>
<dependencies>
项目集成
HivemqProperties
/**
* @author laokou
*/
@Data
public class HivemqProperties {
private boolean auth = true;
private String username = "emqx";
private String password = "laokou123";
private String host = "127.0.0.1";
private int port = 1883;
private String clientId;
private int subscribeQos = 1;
private int publishQos = 0;
private int willQos = 1;
// @formatter:off
/**
* 控制是否创建新会话（true=新建，false=复用历史会话）. clearStart=true => Broker 会在连接断开后立即清除所有会话信息.
* clearStart=false => Broker 会在连接断开后保存会话信息，并在重新连接后复用会话信息.
* <a href="https://github.com/hivemq/hivemq-mqtt-client/issues/627">...</a>
*/
// @formatter:on
private boolean clearStart = false;
private int receiveMaximum = 10000;
private int sendMaximum = 10000;
private int maximumPacketSize = 10000;
private int sendMaximumPacketSize = 10000;
private int topicAliasMaximum = 1024;
private int sendTopicAliasMaximum = 2048;
private long messageExpiryInterval = 86400L;
private boolean requestProblemInformation = true;
private boolean requestResponseInformation = true;
// @formatter:off
/**
* 默认会话保留一天.
* 最大值，4294967295L，会话过期时间【永不过期，单位秒】.
* 定义客户端断开后会话保留的时间（仅在 Clean Session = false 时生效）.
*/
private long sessionExpiryInterval = 86400L;
// @formatter:on
/**
* 心跳包每隔60秒发一次.
*/
private int keepAliveInterval = 60;
private boolean automaticReconnect = true;
private long automaticReconnectMaxDelay = 5;
private long automaticReconnectInitialDelay = 1;
private Set<String> topics = new HashSet<>(0);
private int nettyThreads = 32;
private boolean retain = false;
private boolean noLocal = false;
}
HivemqClientV5
/**
* @author laokou
*/
@Slf4j
public class HivemqClientV5 {
/**
* 响应主题.
*/
private final String RESPONSE_TOPIC = "response/topic";
/**
* 服务下线数据.
*/
private final byte[] WILL_PAYLOAD = "offline".getBytes(UTF_8);
/**
* 相关数据.
*/
private final byte[] CORRELATION_DATA = "correlationData".getBytes(UTF_8);
private final HivemqProperties hivemqProperties;
private final List<MessageHandler> messageHandlers;
private volatile Mqtt5RxClient client;
private final Object lock = new Object();
private volatile Disposable connectDisposable;
private volatile Disposable subscribeDisposable;
private volatile Disposable unSubscribeDisposable;
private volatile Disposable publishDisposable;
private volatile Disposable disconnectDisposable;
private volatile Disposable consumeDisposable;
public HivemqClientV5(HivemqProperties hivemqProperties, List<MessageHandler> messageHandlers) {
this.hivemqProperties = hivemqProperties;
this.messageHandlers = messageHandlers;
}
public void open() {
if (Objects.isNull(client)) {
synchronized (lock) {
if (Objects.isNull(client)) {
client = getMqtt5ClientBuilder().buildRx();
}
}
}
connect();
consume();
}
public void close() {
if (!Objects.isNull(client)) {
disconnectDisposable = client.disconnectWith()
.sessionExpiryInterval(hivemqProperties.getSessionExpiryInterval())
.applyDisconnect()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(() -> log.info("【Hivemq-V5】 => MQTT断开连接成功，客户端ID：{}", hivemqProperties.getClientId()),
e -> log.error("【Hivemq-V5】 => MQTT断开连接失败，错误信息：{}", e.getMessage(), e));
}
}
public void subscribe() {
String[] topics = getTopics();
subscribe(topics, getQosArray(topics));
}
public String[] getTopics() {
return hivemqProperties.getTopics().toArray(String[]::new);
}
public int[] getQosArray(String[] topics) {
return Stream.of(topics).mapToInt(item -> hivemqProperties.getSubscribeQos()).toArray();
}
public void subscribe(String[] topics, int[] qosArray) {
checkTopicAndQos(topics, qosArray);
if (!Objects.isNull(client)) {
List<Mqtt5Subscription> subscriptions = new ArrayList<>(topics.length);
for (int i = 0; i < topics.length; i++) {
subscriptions.add(Mqtt5Subscription.builder()
.topicFilter(topics[i])
.qos(getMqttQos(qosArray[i]))
.retainAsPublished(hivemqProperties.isRetain())
.noLocal(hivemqProperties.isNoLocal())
.build());
}
subscribeDisposable = client.subscribeWith()
.addSubscriptions(subscriptions)
.applySubscribe()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(ack -> log.info("【Hivemq-V5】 => MQTT订阅成功，主题: {}", String.join("、", topics)), e -> log
.error("【Hivemq-V5】 => MQTT订阅失败，主题：{}，错误信息：{}", String.join("、", topics), e.getMessage(), e));
}
}
public void unSubscribe() {
String[] topics = hivemqProperties.getTopics().toArray(String[]::new);
unSubscribe(topics);
}
public void unSubscribe(String[] topics) {
checkTopic(topics);
if (!Objects.isNull(client)) {
List<MqttTopicFilter> matchedTopics = new ArrayList<>(topics.length);
for (String topic : topics) {
matchedTopics.add(MqttTopicFilter.of(topic));
}
unSubscribeDisposable = client.unsubscribeWith()
.addTopicFilters(matchedTopics)
.applyUnsubscribe()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(ack -> log.info("【Hivemq-V5】 => MQTT取消订阅成功，主题：{}", String.join("、", topics)), e -> log
.error("【Hivemq-V5】 => MQTT取消订阅失败，主题：{}，错误信息：{}", String.join("、", topics), e.getMessage(), e));
}
}
public void publish(String topic, byte[] payload, int qos) {
if (!Objects.isNull(client)) {
publishDisposable = client
.publish(Flowable.just(Mqtt5Publish.builder()
.topic(topic)
.qos(getMqttQos(qos))
.payload(payload)
.noMessageExpiry()
.retain(hivemqProperties.isRetain())
.messageExpiryInterval(hivemqProperties.getMessageExpiryInterval())
.correlationData(CORRELATION_DATA)
.payloadFormatIndicator(Mqtt5PayloadFormatIndicator.UTF_8)
.contentType("text/plain")
.responseTopic(RESPONSE_TOPIC)
.build()))
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(ack -> log.info("【Hivemq-V5】 => MQTT消息发布成功，topic：{}", topic),
e -> log.error("【Hivemq-V5】 => MQTT消息发布失败，topic：{}，错误信息：{}", topic, e.getMessage(), e));
}
}
public void publish(String topic, byte[] payload) {
publish(topic, payload, hivemqProperties.getPublishQos());
}
public void dispose(Disposable disposable) {
if (!Objects.isNull(disposable) && !disposable.isDisposed()) {
// 显式取消订阅
disposable.dispose();
}
}
public void dispose() {
dispose(connectDisposable);
dispose(subscribeDisposable);
dispose(unSubscribeDisposable);
dispose(publishDisposable);
dispose(consumeDisposable);
dispose(disconnectDisposable);
}
public void reSubscribe() {
log.info("【Hivemq-V5】 => MQTT重新订阅开始");
dispose(subscribeDisposable);
subscribe();
log.info("【Hivemq-V5】 => MQTT重新订阅结束");
}
private MqttQos getMqttQos(int qos) {
return MqttQos.fromCode(qos);
}
private void connect() {
connectDisposable = client.connectWith()
.keepAlive(hivemqProperties.getKeepAliveInterval())
.cleanStart(hivemqProperties.isClearStart())
.sessionExpiryInterval(hivemqProperties.getSessionExpiryInterval())
.willPublish()
.topic("will/topic")
.payload(WILL_PAYLOAD)
.qos(getMqttQos(hivemqProperties.getWillQos()))
.retain(true)
.messageExpiryInterval(100)
.delayInterval(10)
.payloadFormatIndicator(Mqtt5PayloadFormatIndicator.UTF_8)
.contentType("text/plain")
.responseTopic(RESPONSE_TOPIC)
.correlationData(CORRELATION_DATA)
.applyWillPublish()
.restrictions()
.receiveMaximum(hivemqProperties.getReceiveMaximum())
.sendMaximum(hivemqProperties.getSendMaximum())
.maximumPacketSize(hivemqProperties.getMaximumPacketSize())
.sendMaximumPacketSize(hivemqProperties.getSendMaximumPacketSize())
.topicAliasMaximum(hivemqProperties.getTopicAliasMaximum())
.sendTopicAliasMaximum(hivemqProperties.getSendTopicAliasMaximum())
.requestProblemInformation(hivemqProperties.isRequestProblemInformation())
.requestResponseInformation(hivemqProperties.isRequestResponseInformation())
.applyRestrictions()
.applyConnect()
.toFlowable()
.firstElement()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(
ack -> log.info("【Hivemq-V5】 => MQTT连接成功，主机：{}，端口：{}，客户端ID：{}", hivemqProperties.getHost(),
hivemqProperties.getPort(), hivemqProperties.getClientId()),
e -> log.error("【Hivemq-V5】 => MQTT连接失败，错误信息：{}", e.getMessage(), e));
}
private void consume() {
if (!Objects.isNull(client)) {
consumeDisposable = client.publishes(MqttGlobalPublishFilter.ALL)
.onBackpressureBuffer(8192)
.observeOn(Schedulers.computation(), false, 8192)
.doOnSubscribe(subscribe -> {
log.info("【Hivemq-V5】 => MQTT开始订阅消息，请稍候。。。。。。");
reSubscribe();
})
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(publish -> {
for (MessageHandler messageHandler : messageHandlers) {
if (messageHandler.isSubscribe(publish.getTopic().toString())) {
log.info("【Hivemq-V5】 => MQTT接收到消息，Topic：{}", publish.getTopic());
messageHandler
.handle(new MqttMessage(publish.getPayloadAsBytes(), publish.getTopic().toString()));
}
}
}, e -> log.error("【Hivemq-V5】 => MQTT消息处理失败，错误信息：{}", e.getMessage(), e),
() -> log.info("【Hivemq-V5】 => MQTT订阅消息结束，请稍候。。。。。。"));
}
}
private Mqtt5ClientBuilder getMqtt5ClientBuilder() {
Mqtt5ClientBuilder builder = Mqtt5Client.builder().addConnectedListener(listener -> {
Optional<? extends MqttClientConnectionConfig> config = Optional
.of(listener.getClientConfig().getConnectionConfig())
.get();
config.ifPresent(mqttClientConnectionConfig -> log.info("【Hivemq-V5】 => MQTT连接保持时间：{}ms",
mqttClientConnectionConfig.getKeepAlive()));
log.info("【Hivemq-V5】 => MQTT已连接，客户端ID：{}", hivemqProperties.getClientId());
})
.addDisconnectedListener(
listener -> log.error("【Hivemq-V5】 => MQTT已断开连接，客户端ID：{}", hivemqProperties.getClientId()))
.identifier(hivemqProperties.getClientId())
.serverHost(hivemqProperties.getHost())
.serverPort(hivemqProperties.getPort())
.executorConfig(MqttClientExecutorConfig.builder()
.nettyExecutor(ThreadUtils.newVirtualTaskExecutor())
.nettyThreads(hivemqProperties.getNettyThreads())
.applicationScheduler(Schedulers.from(ThreadUtils.newVirtualTaskExecutor()))
.build());
// 开启重连
if (hivemqProperties.isAutomaticReconnect()) {
builder.automaticReconnect()
.initialDelay(hivemqProperties.getAutomaticReconnectInitialDelay(), TimeUnit.SECONDS)
.maxDelay(hivemqProperties.getAutomaticReconnectMaxDelay(), TimeUnit.SECONDS)
.applyAutomaticReconnect();
}
if (hivemqProperties.isAuth()) {
builder.simpleAuth()
.username(hivemqProperties.getUsername())
.password(hivemqProperties.getPassword().getBytes())
.applySimpleAuth();
}
return builder;
}
private void checkTopicAndQos(String[] topics, int[] qosArray) {
if (topics == null || qosArray == null) {
throw new IllegalArgumentException("【" + "Hivemq-V5" + "】 => Topics and QoS arrays cannot be null");
}
if (topics.length != qosArray.length) {
throw new IllegalArgumentException("【" + "Hivemq-V5" + "】 => Topics and QoS arrays must have the same length");
}
if (topics.length == 0) {
throw new IllegalArgumentException("【" + "Hivemq-V5" + "】 => Topics array cannot be empty");
}
}
private void checkTopic(String[] topics) {
if (topics.length == 0) {
throw new IllegalArgumentException("【" + "Hivemq-V5" + "】 => Topics array cannot be empty");
}
}
}
HivemqV5MqttClientTest
/**
* @author laokou
*/
@SpringBootTest
@RequiredArgsConstructor
@TestConstructor(autowireMode = TestConstructor.AutowireMode.ALL)
class HivemqV5MqttClientTest {
private final List<MessageHandler> messageHandlers;
@Test
void testMqttClient() throws InterruptedException {
HivemqProperties hivemqProperties = new HivemqProperties();
hivemqProperties.setClientId("test-client-1");
hivemqProperties.setTopics(Set.of("/test-topic-1/#"));
HivemqClientV5 hivemqClientV5 = new HivemqClientV5(hivemqProperties, messageHandlers);
hivemqClientV5.open();
hivemqClientV5.publish("/test-topic-1/123", "Hello World123".getBytes());
}
}
HivemqClientV3
/**
* @author laokou
*/
@Slf4j
public class HivemqClientV3 {
/**
* 服务下线数据.
*/
private final byte[] WILL_PAYLOAD = "offline".getBytes(UTF_8);
private final HivemqProperties hivemqProperties;
private final List<MessageHandler> messageHandlers;
private volatile Mqtt3RxClient client;
private final Object lock = new Object();
private volatile Disposable connectDisposable;
private volatile Disposable subscribeDisposable;
private volatile Disposable unSubscribeDisposable;
private volatile Disposable publishDisposable;
private volatile Disposable disconnectDisposable;
private volatile Disposable consumeDisposable;
public HivemqClientV3(HivemqProperties hivemqProperties, List<MessageHandler> messageHandlers) {
this.hivemqProperties = hivemqProperties;
this.messageHandlers = messageHandlers;
}
public void open() {
if (Objects.isNull(client)) {
synchronized (lock) {
if (Objects.isNull(client)) {
client = getMqtt3ClientBuilder().buildRx();
}
}
}
connect();
consume();
}
public void close() {
if (!Objects.isNull(client)) {
disconnectDisposable = client.disconnect()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(() -> log.info("【Hivemq-V3】 => MQTT断开连接成功，客户端ID：{}", hivemqProperties.getClientId()),
e -> log.error("【Hivemq-V3】 => MQTT断开连接失败，错误信息：{}", e.getMessage(), e));
}
}
public void subscribe() {
String[] topics = getTopics();
subscribe(topics, getQosArray(topics));
}
public String[] getTopics() {
return hivemqProperties.getTopics().toArray(String[]::new);
}
public int[] getQosArray(String[] topics) {
return Stream.of(topics).mapToInt(item -> hivemqProperties.getSubscribeQos()).toArray();
}
public void subscribe(String[] topics, int[] qosArray) {
checkTopicAndQos(topics, qosArray);
if (!Objects.isNull(client)) {
List<Mqtt3Subscription> subscriptions = new ArrayList<>(topics.length);
for (int i = 0; i < topics.length; i++) {
subscriptions.add(Mqtt3Subscription.builder()
.topicFilter(topics[i])
.qos(getMqttQos(qosArray[i]))
.build());
}
subscribeDisposable = client.subscribeWith()
.addSubscriptions(subscriptions)
.applySubscribe()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(ack -> log.info("【Hivemq-V3】 => MQTT订阅成功，主题: {}", String.join("、", topics)), e -> log
.error("【Hivemq-V3】 => MQTT订阅失败，主题：{}，错误信息：{}", String.join("、", topics), e.getMessage(), e));
}
}
public void unSubscribe() {
String[] topics = hivemqProperties.getTopics().toArray(String[]::new);
unSubscribe(topics);
}
public void unSubscribe(String[] topics) {
checkTopic(topics);
if (!Objects.isNull(client)) {
List<MqttTopicFilter> matchedTopics = new ArrayList<>(topics.length);
for (String topic : topics) {
matchedTopics.add(MqttTopicFilter.of(topic));
}
unSubscribeDisposable = client.unsubscribeWith()
.addTopicFilters(matchedTopics)
.applyUnsubscribe()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(() -> log.info("【Hivemq-V3】 => MQTT取消订阅成功，主题：{}", String.join("、", topics)), e -> log
.error("【Hivemq-V3】 => MQTT取消订阅失败，主题：{}，错误信息：{}", String.join("、", topics), e.getMessage(), e));
}
}
public void publish(String topic, byte[] payload, int qos) {
if (!Objects.isNull(client)) {
publishDisposable = client
.publish(Flowable.just(Mqtt3Publish.builder()
.topic(topic)
.qos(getMqttQos(qos))
.payload(payload)
.retain(hivemqProperties.isRetain())
.build()))
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(ack -> log.info("【Hivemq-V3】 => MQTT消息发布成功，topic：{}", topic),
e -> log.error("【Hivemq-V3】 => MQTT消息发布失败，topic：{}，错误信息：{}", topic, e.getMessage(), e));
}
}
public void publish(String topic, byte[] payload) {
publish(topic, payload, hivemqProperties.getPublishQos());
}
public void dispose(Disposable disposable) {
if (!Objects.isNull(disposable) && !disposable.isDisposed()) {
// 显式取消订阅
disposable.dispose();
}
}
public void dispose() {
dispose(connectDisposable);
dispose(subscribeDisposable);
dispose(unSubscribeDisposable);
dispose(publishDisposable);
dispose(consumeDisposable);
dispose(disconnectDisposable);
}
public void reSubscribe() {
log.info("【Hivemq-V3】 => MQTT重新订阅开始");
dispose(subscribeDisposable);
subscribe();
log.info("【Hivemq-V3】 => MQTT重新订阅结束");
}
private MqttQos getMqttQos(int qos) {
return MqttQos.fromCode(qos);
}
private void connect() {
connectDisposable = client.connectWith()
.keepAlive(hivemqProperties.getKeepAliveInterval())
.willPublish()
.topic("will/topic")
.payload(WILL_PAYLOAD)
.qos(getMqttQos(hivemqProperties.getWillQos()))
.retain(true)
.applyWillPublish()
.restrictions()
.sendMaximum(hivemqProperties.getSendMaximum())
.sendMaximumPacketSize(hivemqProperties.getSendMaximumPacketSize())
.applyRestrictions()
.applyConnect()
.toFlowable()
.firstElement()
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(
ack -> log.info("【Hivemq-V3】 => MQTT连接成功，主机：{}，端口：{}，客户端ID：{}", hivemqProperties.getHost(),
hivemqProperties.getPort(), hivemqProperties.getClientId()),
e -> log.error("【Hivemq-V3】 => MQTT连接失败，错误信息：{}", e.getMessage(), e));
}
private void consume() {
if (!Objects.isNull(client)) {
consumeDisposable = client.publishes(MqttGlobalPublishFilter.ALL)
.onBackpressureBuffer(8192)
.observeOn(Schedulers.computation(), false, 8192)
.doOnSubscribe(subscribe -> {
log.info("【Hivemq-V3】 => MQTT开始订阅消息，请稍候。。。。。。");
reSubscribe();
})
.subscribeOn(Schedulers.io())
.retryWhen(errors -> errors.scan(1, (retryCount, error) -> retryCount > 5 ? -1 : retryCount + 1)
.takeWhile(retryCount -> retryCount != -1)
.flatMap(retryCount -> Flowable.timer((long) Math.pow(2, retryCount) * 100, TimeUnit.MILLISECONDS)))
.subscribe(publish -> {
for (MessageHandler messageHandler : messageHandlers) {
if (messageHandler.isSubscribe(publish.getTopic().toString())) {
log.info("【Hivemq-V3】 => MQTT接收到消息，Topic：{}", publish.getTopic());
messageHandler
.handle(new MqttMessage(publish.getPayloadAsBytes(), publish.getTopic().toString()));
}
}
}, e -> log.error("【Hivemq-V3】 => MQTT消息处理失败，错误信息：{}", e.getMessage(), e),
() -> log.info("【Hivemq-V3】 => MQTT订阅消息结束，请稍候。。。。。。"));
}
}
private Mqtt3ClientBuilder getMqtt3ClientBuilder() {
Mqtt3ClientBuilder builder = Mqtt3Client.builder().addConnectedListener(listener -> {
Optional<? extends MqttClientConnectionConfig> config = Optional
.of(listener.getClientConfig().getConnectionConfig())
.get();
config.ifPresent(mqttClientConnectionConfig -> log.info("【Hivemq-V5】 => MQTT连接保持时间：{}ms",
mqttClientConnectionConfig.getKeepAlive()));
log.info("【Hivemq-V3】 => MQTT已连接，客户端ID：{}", hivemqProperties.getClientId());
})
.addDisconnectedListener(
listener -> log.error("【Hivemq-V3】 => MQTT已断开连接，客户端ID：{}", hivemqProperties.getClientId()))
.identifier(hivemqProperties.getClientId())
.serverHost(hivemqProperties.getHost())
.serverPort(hivemqProperties.getPort())
.executorConfig(MqttClientExecutorConfig.builder()
.nettyExecutor(ThreadUtils.newVirtualTaskExecutor())
.nettyThreads(hivemqProperties.getNettyThreads())
.applicationScheduler(Schedulers.from(ThreadUtils.newVirtualTaskExecutor()))
.build());
// 开启重连
if (hivemqProperties.isAutomaticReconnect()) {
builder.automaticReconnect()
.initialDelay(hivemqProperties.getAutomaticReconnectInitialDelay(), TimeUnit.SECONDS)
.maxDelay(hivemqProperties.getAutomaticReconnectMaxDelay(), TimeUnit.SECONDS)
.applyAutomaticReconnect();
}
if (hivemqProperties.isAuth()) {
builder.simpleAuth()
.username(hivemqProperties.getUsername())
.password(hivemqProperties.getPassword().getBytes())
.applySimpleAuth();
}
return builder;
}
private void checkTopicAndQos(String[] topics, int[] qosArray) {
if (topics == null || qosArray == null) {
throw new IllegalArgumentException("【" + "Hivemq-V3" + "】 => Topics and QoS arrays cannot be null");
}
if (topics.length != qosArray.length) {
throw new IllegalArgumentException("【" + "Hivemq-V3" + "】 => Topics and QoS arrays must have the same length");
}
if (topics.length == 0) {
throw new IllegalArgumentException("【" + "Hivemq-V3" + "】 => Topics array cannot be empty");
}
}
private void checkTopic(String[] topics) {
if (topics.length == 0) {
throw new IllegalArgumentException("【" + "Hivemq-V3" + "】 => Topics array cannot be empty");
}
}
}
HivemqV3MqttClientTest
/**
* @author laokou
*/
@SpringBootTest
@RequiredArgsConstructor
@TestConstructor(autowireMode = TestConstructor.AutowireMode.ALL)
class HivemqV3MqttClientTest {
private final List<MessageHandler> messageHandlers;
@Test
void testMqttClient() throws InterruptedException {
HivemqProperties hivemqProperties2 = new HivemqProperties();
hivemqProperties2.setClientId("test-client-2");
hivemqProperties2.setTopics(Set.of("/test-topic-2/#"));
HivemqClientV3 hivemqClientV3 = new HivemqClientV3(hivemqProperties2, messageHandlers);
hivemqClientV3.open();
hivemqClientV3.publish("/test-topic-2/456", "Hello World456".getBytes());
}
}
Vert.x MQTT Client【推荐，只兼容mqtt3.1.1】
引入依赖
<dependencies>
<dependency>
<groupId>io.vertx</groupId>
<artifactId>vertx-mqtt</artifactId>
<version>4.5.14</version>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-core</artifactId>
<version>3.7.5</version>
</dependency>
</dependencies>
项目集成
MqttClientProperties
/**
* @author laokou
*/
@Data
public class MqttClientProperties {
private boolean auth = true;
private String username = "emqx";
private String password = "laokou123";
private String host = "127.0.0.1";
private int port = 1883;
private String clientId = UUIDGenerator.generateUUID();
// @formatter:off
/**
* 控制是否创建新会话（true=新建，false=复用历史会话）. clearStart=true => Broker 会在连接断开后立即清除所有会话信息.
* clearStart=false => Broker 会在连接断开后保存会话信息，并在重新连接后复用会话信息.
*/
// @formatter:on
private boolean clearSession = false;
private int receiveBufferSize = Integer.MAX_VALUE;
private int maxMessageSize = -1;
/**
* 心跳包每隔60秒发一次.
*/
private int keepAliveInterval = 60;
private boolean autoKeepAlive = true;
private long reconnectInterval = 1000;
private int reconnectAttempts = Integer.MAX_VALUE;
private Map<String, Integer> topics = new HashMap<>(0);
private int willQos = 1;
private boolean willRetain = false;
private int ackTimeout = -1;
private boolean autoAck = true;
/**
* 服务下线主题.
*/
private String willTopic = "/will";
/**
* 服务下线数据.
*/
private String willPayload = "offline";
}
VertxConfig
/**
* @author laokou
*/
@Configuration
public class VertxConfig {
@Bean
public Vertx vertx() {
VertxOptions vertxOptions = new VertxOptions();
vertxOptions.setMaxEventLoopExecuteTime(60);
vertxOptions.setMaxWorkerExecuteTime(60);
vertxOptions.setMaxEventLoopExecuteTimeUnit(TimeUnit.SECONDS);
vertxOptions.setMaxWorkerExecuteTimeUnit(TimeUnit.SECONDS);
vertxOptions.setPreferNativeTransport(true);
return Vertx.vertx(vertxOptions);
}
}
VertxMqttClient
注意：vertx-mqtt不支持客户端自动断线重连，网络不通畅或连接关闭，需要自己手动调用连接！！！实现这个重连的功能
/**
* @author laokou
*/
@Slf4j
public class VertxMqttClient {
private final Sinks.Many<MqttPublishMessage> messageSink = Sinks.many()
.multicast()
.onBackpressureBuffer(Integer.MAX_VALUE, false);
private final MqttClient mqttClient;
private final Vertx vertx;
private final MqttClientProperties mqttClientProperties;
private final List<MessageHandler> messageHandlers;
private final List<Disposable> disposables;
private final AtomicBoolean isConnected = new AtomicBoolean(false);
private final AtomicBoolean isLoaded = new AtomicBoolean(false);
private final AtomicBoolean isReconnected = new AtomicBoolean(true);
public VertxMqttClient(final Vertx vertx, final MqttClientProperties mqttClientProperties,
final List<MessageHandler> messageHandlers) {
this.vertx = vertx;
this.mqttClientProperties = mqttClientProperties;
this.mqttClient = MqttClient.create(vertx, getOptions());
this.messageHandlers = messageHandlers;
this.disposables = Collections.synchronizedList(new ArrayList<>());
}
public void open() {
mqttClient.closeHandler(v -> {
isConnected.set(false);
log.error("【Vertx-MQTT】 => MQTT连接断开，客户端ID：{}", mqttClientProperties.getClientId());
reconnect();
})
.publishHandler(messageSink::tryEmitNext)
// 仅接收QoS1和QoS2的消息
.publishCompletionHandler(id -> {
// log.info("【Vertx-MQTT】 => 接收MQTT的PUBACK或PUBCOMP数据包，数据包ID：{}", id);
})
.subscribeCompletionHandler(ack -> {
// log.info("【Vertx-MQTT】 => 接收MQTT的SUBACK数据包，数据包ID：{}", ack.messageId());
})
.unsubscribeCompletionHandler(id -> {
// log.info("【Vertx-MQTT】 => 接收MQTT的UNSUBACK数据包，数据包ID：{}", id);
})
.pingResponseHandler(s -> {
// log.info("【Vertx-MQTT】 => 接收MQTT的PINGRESP数据包");
})
.connect(mqttClientProperties.getPort(), mqttClientProperties.getHost(), connectResult -> {
if (connectResult.succeeded()) {
isConnected.set(true);
log.info("【Vertx-MQTT】 => MQTT连接成功，主机：{}，端口：{}，客户端ID：{}", mqttClientProperties.getHost(),
mqttClientProperties.getPort(), mqttClientProperties.getClientId());
resubscribe();
}
else {
isConnected.set(false);
Throwable ex = connectResult.cause();
log.error("【Vertx-MQTT】 => MQTT连接失败，原因：{}，客户端ID：{}", ex.getMessage(),
mqttClientProperties.getClientId(), ex);
reconnect();
}
});
}
public void close() {
disconnect();
}
/**
* Sends the PUBLISH message to the remote MQTT server.
* @param topic topic on which the message is published
* @param payload message payload
* @param qos QoS level
* @param isDup if the message is a duplicate
* @param isRetain if the message needs to be retained
*/
public void publish(String topic, int qos, String payload, boolean isDup, boolean isRetain) {
mqttClient.publish(topic, Buffer.buffer(payload), convertQos(qos), isDup, isRetain);
}
private void reconnect() {
if (isReconnected.get()) {
log.info("【Vertx-MQTT】 => MQTT尝试重连");
vertx.setTimer(mqttClientProperties.getReconnectInterval(),
handler -> ThreadUtils.newVirtualTaskExecutor().execute(this::open));
}
}
private void subscribe() {
Map<String, Integer> topics = mqttClientProperties.getTopics();
checkTopicAndQos(topics);
mqttClient.subscribe(topics, subscribeResult -> {
if (subscribeResult.succeeded()) {
log.info("【Vertx-MQTT】 => MQTT订阅成功，主题: {}", String.join("、", topics.keySet()));
}
else {
Throwable ex = subscribeResult.cause();
log.error("【Vertx-MQTT】 => MQTT订阅失败，主题：{}，错误信息：{}", String.join("、", topics.keySet()), ex.getMessage(),
ex);
}
});
}
private void resubscribe() {
if (isConnected.get() || mqttClient.isConnected()) {
ThreadUtils.newVirtualTaskExecutor().execute(this::subscribe);
}
if (isLoaded.compareAndSet(false, true)) {
ThreadUtils.newVirtualTaskExecutor().execute(this::consume);
}
}
private void consume() {
Disposable disposable = messageSink.asFlux().doOnNext(mqttPublishMessage -> {
String topic = mqttPublishMessage.topicName();
log.info("【Vertx-MQTT】 => MQTT接收到消息，Topic：{}", topic);
for (MessageHandler messageHandler : messageHandlers) {
if (messageHandler.isSubscribe(topic)) {
messageHandler.handle(new MqttMessage(mqttPublishMessage.payload(), topic));
}
}
}).subscribeOn(Schedulers.boundedElastic()).subscribe();
disposables.add(disposable);
}
private void disposable() {
for (Disposable disposable : disposables) {
if (ObjectUtils.isNotNull(disposable) && !disposable.isDisposed()) {
disposable.dispose();
}
}
}
private void disconnect() {
isReconnected.set(false);
mqttClient.disconnect(disconnectResult -> {
if (disconnectResult.succeeded()) {
disposable();
log.info("【Vertx-MQTT】 => MQTT断开连接成功");
disposables.clear();
}
else {
Throwable ex = disconnectResult.cause();
log.error("【Vertx-MQTT】 => MQTT断开连接失败，错误信息：{}", ex.getMessage(), ex);
}
});
}
private void unsubscribe(List<String> topics) {
checkTopic(topics);
mqttClient.unsubscribe(topics, unsubscribeResult -> {
if (unsubscribeResult.succeeded()) {
log.info("【Vertx-MQTT】 => MQTT取消订阅成功，主题：{}", String.join("、", topics));
}
else {
Throwable ex = unsubscribeResult.cause();
log.error("【Vertx-MQTT】 => MQTT取消订阅失败，主题：{}，错误信息：{}", String.join("、", topics), ex.getMessage(), ex);
}
});
}
private MqttClientOptions getOptions() {
MqttClientOptions options = new MqttClientOptions();
options.setClientId(mqttClientProperties.getClientId());
options.setCleanSession(mqttClientProperties.isClearSession());
options.setAutoKeepAlive(mqttClientProperties.isAutoKeepAlive());
options.setKeepAliveInterval(mqttClientProperties.getKeepAliveInterval());
options.setReconnectAttempts(mqttClientProperties.getReconnectAttempts());
options.setReconnectInterval(mqttClientProperties.getReconnectInterval());
options.setWillQoS(mqttClientProperties.getWillQos());
options.setWillTopic(mqttClientProperties.getWillTopic());
options.setAutoAck(mqttClientProperties.isAutoAck());
options.setAckTimeout(mqttClientProperties.getAckTimeout());
options.setWillRetain(mqttClientProperties.isWillRetain());
options.setWillMessageBytes(Buffer.buffer(mqttClientProperties.getWillPayload()));
options.setReceiveBufferSize(mqttClientProperties.getReceiveBufferSize());
options.setMaxMessageSize(mqttClientProperties.getMaxMessageSize());
if (mqttClientProperties.isAuth()) {
options.setPassword(mqttClientProperties.getPassword());
options.setUsername(mqttClientProperties.getUsername());
}
return options;
}
private void checkTopicAndQos(Map<String, Integer> topics) {
topics.forEach((topic, qos) -> {
if (StringUtils.isEmpty(topic) || ObjectUtils.isNull(qos)) {
throw new IllegalArgumentException("【Vertx-MQTT】 => Topic and QoS cannot be null");
}
});
}
private void checkTopic(List<String> topics) {
if (CollectionUtils.isEmpty(topics)) {
throw new IllegalArgumentException("【Vertx-MQTT】 => Topics list cannot be empty");
}
}
private MqttQoS convertQos(int qos) {
return MqttQoS.valueOf(qos);
}
}
VertxMqttClientTest
/**
* @author laokou
*/
@SpringBootTest
@RequiredArgsConstructor
@ContextConfiguration(classes = { DefaultMessageHandler.class, VertxConfig.class })
@TestConstructor(autowireMode = TestConstructor.AutowireMode.ALL)
class VertxMqttClientTest {
private final List<MessageHandler> messageHandlers;
private final Vertx vertx;
@Test
void testMqttClient() throws InterruptedException {
MqttClientProperties properties = new MqttClientProperties();
properties.setHost("127.0.0.1");
properties.setPort(1883);
properties.setUsername("emqx");
properties.setPassword("laokou123");
properties.setClientId("test-client-1");
properties.setTopics(Map.of("/test-topic-1/#", 1));
VertxMqttClient vertxMqttClient = new VertxMqttClient(vertx, properties, messageHandlers);
Assertions.assertDoesNotThrow(vertxMqttClient::open);
Thread.sleep(500);
Assertions.assertDoesNotThrow(() -> vertxMqttClient.publish("/test-topic-1/test", 1, "test", false, false));
Thread.sleep(500);
Assertions.assertDoesNotThrow(vertxMqttClient::close);
Thread.sleep(500);
}
}
非常推荐使用vertx-mqtt，项目平稳运行好用！！！
但是，需要时注意的是，项目部署到Linux系统，需要最少分配 -Xmx2100m -Xms2100m 内存，不然连接会关闭！
我是老寇，我们下次再见啦~
物联网之对接MQTT最佳实践的更多相关文章
- 海量大数据大屏分析展示一步到位：DataWorks数据服务对接DataV最佳实践
1. 概述 数据服务(https://ds-cn-shanghai.data.aliyun.com) 是DataWorks产品家族的一员,提供了快速将数据表生成API的能力,通过可视化的向导,一分钟 ...
- 海量大数据大屏分析展示一步到位：DataWorks数据服务+MaxCompute Lightning对接DataV最佳实践
1. 概述 数据服务(https://ds-cn-shanghai.data.aliyun.com) 是DataWorks产品家族的一员,提供了快速将数据表生成API的能力,通过可视化的向导,一分钟“ ...
- Ubuntu14.04+RabbitMQ3.6.3+Golang的最佳实践
目录 [TOC] 1.RabbitMQ介绍 1.1.什么是RabbitMQ? RabbitMQ 是由 LShift 提供的一个 Advanced Message Queuing Protocol ...
- 基于AngularJS的前端云组件最佳实践
AngularJS是google设计和开发的一套前端开发框架,他能帮助开发人员更便捷地进行前端开发.AngularJS是为了克服HTML在构建应用上的不足而设计的,它非常全面且简单易学习,因此Angu ...
- 从Uber微服务看最佳实践如何炼成？
导读:Uber成长非常迅速,工程师团队快速扩充,据说Uber有2000名工程师,8000个代码仓库,部署了1000多个微服务.微服务架构是Uber应对技术团队快速增长,功能快速上线很出色的解决方案.本 ...
- 《HBase在滴滴出行的应用场景和最佳实践》
HBase在滴滴出行的应用场景和最佳实践 背景 对接业务类型 HBase是建立在Hadoop生态之上的Database,源生对离线任务支持友好,又因为LSM树是一个优秀的高吞吐数据库结构,所以同时 ...
- QingStor 对象存储架构设计及最佳实践
对象存储概念及特性 在介绍 QingStor️对象存储内部的的架构和设计原理之前,我们首先来了解一下对象存储的概念,也就是从外部视角看,对象存储有什么特性,我们应该如何使用. 对象存储本质上是一款存储 ...
- 微信小程序自动化测试最佳实践（附 Python 源码）
本文为霍格沃兹测试学院测试大咖公开课<微信小程序自动化测试>图文整理精华版. 随着微信小程序的功能和生态日益完善,很多公司的产品业务形态逐渐从 App 延升到微信小程序.微信公众号等.小程 ...
- Istio最佳实践系列：如何实现方法级调用跟踪？
赵化冰,腾讯云高级工程师,Istio Member,ServiceMesher 管理委员,Istio 项目贡献者,热衷于开源.网络和云计算.目前主要从事服务网格的开源和研发工作. 引言 TCM(Ten ...
- Netty基础招式——ChannelHandler的最佳实践
本文是Netty系列第7篇 上一篇文章我们深入学习了Netty逻辑架构中的核心组件EventLoop和EventLoopGroup,掌握了Netty的线程模型,并且介绍了Netty4线程模型中的无锁串 ...
随机推荐
- RowCellMenuCustomizations 实现 Command 绑定
给GridControl的行数据单元格添加菜单项,并通过Command绑定的方式实现菜单点击动作触发: <dxg:GridControl x:Name="mainGrid" ...
- autMan奥特曼机器人-内置微信如何定时给公众号发消息
autMan版本要求2.1.3以上 一.打开左侧栏的本地开发,然后从实时日志获取公众号的ID或名称 ![2024-10-23T01:45:34.png][1] ![2024-10-23T01:44:5 ...
- Linux - 基础环境检查
检查操作系统:建议根据实际产品需要进行安装 检查主机名:集群中统一前缀并区分服务器功能,小写命名 检查内存:建议至少128G 检查CPU:建议至少2个支持超线程技术的10核芯片 检查磁盘:同一功能的服 ...
- Kali Linux（202104）重置root账户密码
1.前言 如果忘记了Kali Linux系统的登录密码,最关键的需求就是重置root用户的登录密码, 之后使用root账户可以修改其他账户的密码. 因此, 本文就介绍一下在不知道root用户登录密码的 ...
- VMware虚拟机上安装Kali Linux详细教程
1.Kali Linux简介 Kali Linux是一个基于Debian的开源Linux发行版,集成了精心挑选的渗透测试和安全审计的工具,供渗透测试和安全设计人员使用,面向各种信息安全任务:如渗透测试 ...
- 深度研究JDK的各种技术细节
打算建立一个JDK网站,将目前JDK的各种重要特性都深入分析一下.希望JDK中各种技术实现细节都可以在这个网站上查到.相关的模块以及阅读顺序如下图所示. 没有将一些内容规划进来,Java语言基本语法太 ...
- 你好，新朋友：生成式AI的第一次对话
像学习使用智能手机一样开启AI对话 一.从"第一次用智能手机"理解AI交互 还记得初次使用智能手机时的笨拙吗?滑动解锁.输入文字.下载应用-每一步都需要探索.生成式AI的对话也遵循 ...
- 【FAQ】HarmonyOS SDK 闭源开放能力 —Map Kit（5）
1.问题描述: 提供两套标准方案,可根据体验需求选择: 1.地图Picker(地点详情) 用户体验:①展示地图 ②标记地点 ③用户选择已安装地图应用 接入文档:https://developer.hu ...
- TSP问题的不可近似性
\(\S\) 结论 TSP问题:n阶带权无向完全图中,找权值最小的哈密顿回路(无向图中遍历所有顶点的回路) 优化问题,记最优解为OPT 对于一般的n顶点TSP问题(非Metric),任意 多项式时间内 ...
- [tldr]windows使用scoop安装make工具辅助程序编译
make是一个好用的GNU工具,用来辅助我们进行自动化的程序编译,只需要一个Makefile文件,即可实现一行指令自动编译 scoop是windows的一个包管理工具 安装 scoop bucket ...