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Doker官网:Doker 多克
一、添加maven依赖:
org.apache.rocketmq
rocketmq-spring-boot-starter
${RELEASE.VERSION}
二、发送消息
1、修改application.properties
## application.properties
rocketmq.name-server=127.0.0.1:9876
rocketmq.producer.group=my-group
注意:
请将上述示例配置中的127.0.0.1:9876替换成真实RocketMQ的NameServer地址与端口
2、编写代码
@SpringBootApplication
public class ProducerApplication implements CommandLineRunner{
@Resource
private RocketMQTemplate rocketMQTemplate;
public static void main(String[] args){
SpringApplication.服务器托管网run(ProducerApplication.class, args);
}
public void run(String... args) throws Exception {
//send message synchronously
rocketMQTemplate.convertAndSend("test-topic-1", "Hello, World!");
//send spring message
rocketMQTemplate.send("test-topic-1", MessageBuilder.withPayload("Hello, World! I'm from spring message").build());
//send messgae asynchronously
rocketMQTemplate.asyncSend("test-topic-2", new OrderPaidEvent("T_001", new BigDecimal("88.00")), new SendCallback() {
@Override
public void onSuccess(SendResult var1) {
System.out.printf("async onSucess SendResult=%s %n", var1);
}
@Override
public void onException(Throwable var1) {
System.out.printf("async onException Throwable=%s %n", var1);
}
});
//Send messages orderly
rocketMQTemplate.syncSendOrderly("orderly_topic",MessageBuilder.withPayload("Hello, World").build(),"hashkey")
//rocketMQTemplate.destroy(); // notes: once rocketMQTemplate be destroyed, you can not send any message again with this rocketMQTemplate
}
@Data
@AllArgsConstructor
public class OrderPaidEvent implements Serializable{
private String orderId;
private BigDecimal paidMoney;
}
}
三、接收消息
1、Push模式
修改application.properties
## application.properties
rocketmq.name-server=127.0.0.1:9876
注意:
请将上述示例配置中的127.0.0.1:9876替换成真实RocketMQ的NameServer地址与端口
@SpringBootApplication
public class ConsumerApplication{
public static void main(String[] args){
SpringApplication.run(ConsumerApplication.class, args);
}
@Slf4j
@Service
@RocketMQMessageListener(topic = "test-topic-1", consumerGroup = "my-consumer_test-topic-1")
public class MyConsumer1 implements RocketMQListener{
public void onMessage(String message) {
log.info("received message: {}", message);
}
}
@Slf4j
@Service
@RocketMQMessageListener(topic = "test-topic-2", consumerGroup = "my-consumer_test-topic-2")
public class MyConsumer2 implements RocketMQListener{
public void onMessage(OrderPaidEvent orderPaidEvent) {
log.info("received orderPaidEvent: {}", orderPaidEvent);
}
}
}
2、Pull模式
从RocketMQ Spring 2.2.0开始,RocketMQ Srping支持Pull模式消费
修改application.properties
## application.properties
rocketmq.name-server=127.0.0.1:9876
# When set rocketmq.pull-consumer.group and rocketmq.pull-consumer.topic, rocketmqTemplate will start lite pull consumer
# If you do not want to use lite pull consumer, please do not set rocketmq.pull-consumer.group and rocketmq.pull-consumer.topic
rocketmq.pull-consumer.group=my-group1
rocketmq.pull-consumer.topic=test
注意之前lite pull consumer的生效配置为rocketmq.consumer.group和rocketmq.consumer.topic,但由于非常容易与push-consumer混淆,因此在2.2.3版本之后修改为rocketmq.pull-consumer.group和rocketmq.pull-consumer.topic.
编写代码
@SpringBootApplication
public class ConsumerApplication implements CommandLineRunner {
@Resource
private RocketMQTemplate rocketMQTemplate;
@Resource(name = "extRocketMQTemplate")
private RocketMQTemplate extRocketMQTemplate;
public static void main(String[] args) {
SpringApplication.run(ConsumerApplication.class, args);
}
@Override
public void run(String... args) throws Exception {
//This is an example of pull consumer using rocketMQTemplate.
List messages = rocketMQTemplate.receive(String.class);
System.out.printf("receive from rocketMQTemplate, messages=%s %n", messages);
//This is an example of pull consumer using extRocketMQTemplate.
messages = extRocketMQTemplate.receive(String.class);
System.out.printf("receive from extRocketMQTemplate, messages=%s %n", messages);
}
}
四、事务消息
修改application.properties
## application.propertiesrocketmq.name-server=127.0.0.1:9876
rocketmq.producer.group=my-group
注意:
请将上述示例配置中的127.0.0.1:9876替换成真实RocketMQ的NameServer地址与端口
@SpringBootApplication
public class ProducerApplication implements CommandLineRunner{
@Resource
private RocketMQTemplate rocketMQTemplate;
public static void main(String[] args){
SpringApplication.run(ProducerApplication.class, args);
}
public void run(String... args) throws Exception {
try {
// Build a SpringMessage for sending in transaction
Message msg = MessageBuilder.withPayload(..)...;
// In sendMessageInTransaction(), the first parameter transaction name ("test")
// must be same with the @RocketMQTransactionListener's member field 'transName'
rocketMQTemplate.sendMessageInTransaction("test-topic", msg, null);
} catch (MQClientException e) {
e.printStackTrace(System.out);
}
}
// Define transaction listener with the annotation @RocketMQTransactionListener
@RocketMQTransactionListener
class TransactionListenerImpl implements RocketMQLocalTransactionListener {
@Override
public RocketMQLocalTransactionState executeLocalTransaction(Message msg, Object arg) {
// ... local transaction process, return bollback, commit or unknown
return RocketMQLocalTransactionState.UNKNOWN;
}
@Override
public RocketMQLocalTransactionState checkLocalTransaction(Message msg) {
// ... check transaction status and return bollback, commit or unknown
return RocketMQLocalTransactionState.COMMIT;
}
}
}
五、消息轨迹
Producer 端要想使用消息轨迹,需要多配置两个配置项:
## application.properties
rocketmq.name-server=127.0.0.1:9876
rocketmq.producer.group=my-group
rocketmq.producer.enable-msg-trace=true
rocketmq.producer.customized-trace-topic=my-trace-topic
Consumer 端消息轨迹的功能需要在 @RocketMQMessageListener 中进行配置对应的属性:
@Service
@RocketMQMessageListener(
topic = "test-topic-1",
consumerGroup = "my-consumer_test-topic-1",
enableMsgTrace = true,
customizedTraceTopic = "my-trace-topic"
)
public class MyConsumer implements RocketMQListener {
...
}
注意:
默认情况下 Producer 和 Consumer 的消息轨迹功能是开启的且 trace-topic 为 RMQ_SYS_TRACE_TOPIC Consumer 端的消息轨迹 trace-topic 可以在配置文件中配置 rocketmq.consumer.customized-trace-topic 配置项,不需要为在每个 @RocketMQMessageListener 配置。
若需使用阿里云消息轨迹,则需要在@RocketMQMessageListener中将accessChannel配置为CLOUD。
六、ACL功能
Producer 端要想使用 ACL 功能,需要多配置两个配置项:
## application.properties
rocketmq.name-server=127.0.0.1:9876
rocketmq.producer.group=my-group
rocketmq.producer.access-key=AK
rocketmq.producer.secret-key=SK
Consumer 端 ACL 功能需要在 @RocketMQMessageListener 中进行配置
@Service
@RocketMQMessageListener(
topic = "test-topic-1",
consumerGroup = "my-consumer_test-topic-1",
accessKey = "AK",
secretKey = "SK"
)
public class MyConsumer implements RocketMQListener {
...
}
注意:
可以不用为每个 @RocketMQMessageListener 注解配置 AK/SK,在配置文件中配置 rocketmq.consumer.access-key 和 rocketmq.consumer.secret-key 配置项,这两个配置项的值就是默认值
七、请求 应答语义支持
RocketMQ-Spring 提供 请求/应答 语义支持。
- Producer端
发送Request消息使用SendAndReceive方法
注意
同步发送需要在方法的参数中指明返回值类型
异步发送需要在回调的接口中指明返回值类型
@SpringBootApplication
public class ProducerApplication implements CommandLineRunner{
@Resource
private RocketMQTemplate rocketMQTemplate;
public static void main(String[] args){
SpringApplication.run(ProducerApplication.class, args);
}
public void run(String... args) throws Exception {
// 同步发送request并且等待String类型的返回值
String replyString = rocketMQTemplate.sendAndReceive("stringRequestTopic", "request string", String.class);
System.out.printf("send %s and receive %s %n", "request string", replyString);
// 异步发送request并且等待User类型的返回值
rocketMQTemplate.sendAndReceive("objectRequestTopic", new User("requestUserName",(byte) 9), new RocketMQLocalRequestCallback() {
@Override public void onSuccess(User message) {
System.out.printf("send user object and receive %s %n", message.toString());
}
@Override public void onException(Throwable e) {
e.printStackTrace();
}
}, 5000);
}
@Data
@AllArgsConstructor
public class User implements Serializable{
private String userName;
private Byte userAge;
}
}
- Consumer端
需要实现RocketMQReplyListener 接口,其中T表示接收值的类型,R表示返回值的类型。
@SpringBootApplication
public class ConsumerApplication{
public static void main(String[] args){
SpringApplication.run(ConsumerApplication.class, args);
}
@Service
@RocketMQMessageListener(topic = "stringRequestTopic", consumerGroup = "stringRequestConsumer")
public class StringConsumerWithReplyString implements RocketMQReplyListener {
@Override
public String onMessage(String message) {
System.out.printf("------- StringConsumerWithReplyString received: %s n", message);
return "reply string";
}
}
@Service
@RocketMQMessageListener(topic = "objectRequestTopic", consumerGroup = "objectRequestConsumer")
public class ObjectConsumerWithReplyUser implements RocketMQReplyListener{
public void onMessage(User user) {
System.out.printf("------- ObjectConsumerWithReplyUser received: %s n", user);
User replyUser = new User("replyUserName",(byte) 10);
return replyUser;
}
}
@Data
@AllArgsConstructor
public class User implements Serializable{
private String userName;
private Byte userAge;
}
}
八、常见问题
- 生产环境有多个nameserver该如何连接?
rocketmq.name-server支持配置多个nameserver地址,采用;分隔即可。例如:172.19.0.1:9876;172.19.0.2:9876
- rocketMQTemplate在什么时候被销毁?
开发者在项目中使用rocketMQTemplate发送消息时,不需要手动执行rocketMQTemplate.destroy()方法, rocketMQTemplate会在spring容器销毁时自动销毁。
- 启动报错:Caused by: org.apache.rocketmq.client.exception.MQClientException: The consumer group[xxx] has been created before, specify another name please
RocketMQ在设计时就不希望一个消费者同时处理多个类型的消息,因此同一个consumerGroup下的consumer职责应该是一样的,不要干不同的事情(即消费多个topic)。建议consumerGroup与topic一一对应。
- 发送的消息内容体是如何被序列化与反序列化的?
RocketMQ的消息体都是以byte[]方式存储。当业务系统的消息内容体如果是java.lang.String类型时,统一按照utf-8编码转成byte[];如果业务系统的消息内容为非java.lang.String类型,则采用jackson-databind序列化成JSON格式的字符串之后,再统一按照utf-8编码转成byte[]。
- 如何指定topic的tags?
RocketMQ的最佳实践中推荐:一个应用尽可能用一个Topic,消息子类型用tags来标识,tags可以由应用自由设置。 在使用rocketMQTemplate发送消息时,通过设置发送方法的destination参数来设置消息的目的地,destination的格式为topicName:tagName,:前面表示topic的名称,后面表示tags名称。
注意:
tags从命名来看像是一个复数,但发送消息时,目的地只能指定一个topic下的一个tag,不能指定多个。
- 发送消息时如何设置消息的key?
可以通过重载的xxxSend(String destination, Message> msg, …)方法来发送消息,指定msg的headers来完成。示例:
Message> message = MessageBuilder.withPayload(payload).setHeader(MessageConst.PROPERTY_KEYS, msgId).build();
rocketMQTemplate.send("topic-test", message);
同理还可以根据上面的方式来设置消息的FLAG、WAIT_STORE_MSG_OK以及一些用户自定义的其它头信息。
注意:
在将Spring的Message转化为RocketMQ的Message时,为防止header信息与RocketMQ的系统属性冲突,在所有header的名称前面都统一添加了前缀USERS_。因此在消费时如果想获取自定义的消息头信息,请遍历头信息中以USERS_开头的key即可。
- 消费消息时,除了获取消息payload外,还想获取RocketMQ消息的其它系统属性,需要怎么做?
消费者在实现RocketMQListener接口时,只需要起泛型为MessageExt即可,这样在onMessage方法将接收到RocketMQ原生的MessageExt消息。
@Slf4j
@Service
@RocketMQMessageListener(topic = "test-topic-1", consumerGroup = "my-consumer_test-topic-1")
public class MyConsumer2 implements RocketMQListener{
public void onMessage(MessageExt messageExt) {
log.info("received messageExt: {}", messageExt);
}
}
- 如何指定消费者从哪开始消费消息,或开始消费的位置?
消费者默认开始消费的位置请参考:RocketMQ FAQ。 若想自定义消费者开始的消费位置,只需在消费者类添加一个RocketMQPushConsumerLifecycleListener接口的实现即可。 示例如下:
@Slf4j
@Service
@RocketMQMessageListener(topic = "test-topic-1", consumerGroup = "my-consumer_test-topic-1")
public class MyConsumer1 implements RocketMQListener, RocketMQPushConsumerLifecycleListener {
@Override
public void onMessage(String message) {
log.info("received message: {}", message);
}
@Override
public void prepareStart(final DefaultMQPushConsumer consumer) {
// set consumer consume message from now
consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_TIMESTAMP);
consumer.setConsumeTimestamp(UtilAll.timeMillisToHumanString3(System.currentTimeMillis()));
}
}
同理,任何关于DefaultMQPushConsumer的更多其它其它配置,都可以采用上述方式来完成。
- 如何发送事务消息?
在客户端,首先用户需要实现RocketMQLocalTransactionListener接口,并在接口类上注解声明@RocketMQTransactionListener,实现确认和回查方法;然后再使用资源模板RocketMQTemplate, 调用方法sendMessageInTransaction()来进行消息的发布。 注意:从RocketMQ-Spring 2.1.0版本之后,注解@RocketMQTransactionListener不能设置txProducerGroup、ak、sk,这些值均与对应的RocketMQTemplate保持一致。
- 如何声明不同name-server或者其他特定的属性来定义非标的RocketMQTemplate?
第一步: 定义非标的RocketMQTemplate使用你需要的属性,可以定义与标准的RocketMQTemplate不同的nameserver、groupname等。如果不定义,它们取全局的配置属性值或默认值。
// 这个RocketMQTemplate的Spring Bean名是'extRocketMQTemplate', 与所定义的类名相同(但首字母小写)
@ExtRocketMQTemplateConfiguration(nameServer="127.0.0.1:9876"
, ... // 定义其他属性,如果有必要。
)
p服务器托管网ublic class ExtRocketMQTemplate extends RocketMQTemplate {
//类里面不需要做任何修改
}
第二步: 使用这个非标RocketMQTemplate
@Resource(name = "extRocketMQTemplate") // 这里必须定义name属性来指向上述具体的Spring Bean.
private RocketMQTemplate extRocketMQTemplate;
接下来就可以正常使用这个extRocketMQTemplate了。
- 如何使用非标的RocketMQTemplate发送事务消息?
首先用户需要实现RocketMQLocalTransactionListener接口,并在接口类上注解声明@RocketMQTransactionListener,注解字段的rocketMQTemplateBeanName指明为非标的RocketMQTemplate的Bean name(若不设置则默认为标准的RocketMQTemplate),比如非标的RocketMQTemplate Bean name为“extRocketMQTemplate”,则代码如下:
@RocketMQTransactionListener(rocketMQTemplateBeanName = "extRocketMQTemplate")
class TransactionListenerImpl implements RocketMQLocalTransactionListener {
@Override
public RocketMQLocalTransactionState executeLocalTransaction(Message msg, Object arg) {
// ... local transaction process, return bollback, commit or unknown
return RocketMQLocalTransactionState.UNKNOWN;
}
@Override
public RocketMQLocalTransactionState checkLocalTransaction(Message msg) {
// ... check transaction status and return bollback, commit or unknown
return RocketMQLocalTransactionState.COMMIT;
}
}
然后使用extRocketMQTemplate调用sendMessageInTransaction()来发送事务消息。
- MessageListener消费端,是否可以指定不同的name-server而不是使用全局定义的’rocketmq.name-server’属性值 ?
@Service
@RocketMQMessageListener(
nameServer = "NEW-NAMESERVER-LIST", // 可以使用这个optional属性来指定不同的name-server
topic = "test-topic-1",
consumerGroup = "my-consumer_test-topic-1",
enableMsgTrace = true,
customizedTraceTopic = "my-trace-topic"
)
public class MyNameServerConsumer implements RocketMQListener {
...
}
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