redis的发布订阅功能
redis提供了简单的发布订阅功能,对于一些合适的场景(比如不要求消费者不在线时也能收到离线消息),比起专业的MQ来说,用起来更简单些。本文主要是记录下怎么在SpringBoot里头使用redis的发布订阅功能。
定义生产者
配置
@Bean
MyPublisher redisPublisher(RedisConnectionFactory factory) {
return new MyPublisher( redisTemplate(factory), topic() );
}
@Bean
ChannelTopic topic() {
return new ChannelTopic( "pubsub:queue" );
}
生产者实例
public class MyPublisher {
private final RedisTemplate< String, Object > template;
private final ChannelTopic topic;
private final AtomicLong counter = new AtomicLong( 0 );
public MyPublisher( final RedisTemplate< String, Object > template,
final ChannelTopic topic ) {
this.template = template;
this.topic = topic;
}
@Scheduled( fixedDelay = 100 )
public void publish() {
template.convertAndSend( topic.getTopic(), "Message " + counter.incrementAndGet() +
", " + Thread.currentThread().getName() );
}
}
定义消费者
配置
//subscribe
@Bean
MessageListenerAdapter messageListener() {
return new MessageListenerAdapter( new MyMessageListener() );
}
@Bean
RedisMessageListenerContainer redisContainer(RedisConnectionFactory factory) {
final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
container.setConnectionFactory(factory);
container.addMessageListener(messageListener(), topic());
return container;
}
消费者实例
public class MyMessageListener implements MessageListener {
@Override
public void onMessage( final Message message, final byte[] pattern ) {
System.out.println( "Message received: " + message.toString() );
}
}
运行
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.3.2.RELEASE)
2016-02-16 00:14:08.190 INFO 1481 --- [ main] com.codecraft.RedisdemoApplication : Starting RedisdemoApplication on Jupiter.local with PID 1481 (/Users/codecraft/workspace/redisdemo/target/classes started by codecraft in /Users/codecraft/workspace/redisdemo)
2016-02-16 00:14:08.193 INFO 1481 --- [ main] com.codecraft.RedisdemoApplication : No active profile set, falling back to default profiles: default
2016-02-16 00:14:08.242 INFO 1481 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@140e5a13: startup date [Tue Feb 16 00:14:08 CST 2016]; root of context hierarchy
2016-02-16 00:14:09.756 INFO 1481 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2016-02-16 00:14:09.763 INFO 1481 --- [ main] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 0
2016-02-16 00:14:09.807 INFO 1481 --- [ main] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 2147483647
2016-02-16 00:14:09.897 INFO 1481 --- [ main] com.codecraft.RedisdemoApplication : Started RedisdemoApplication in 2.215 seconds (JVM running for 2.589)
Message received: "Message 1, pool-1-thread-1"
Message received: "Message 2, pool-1-thread-1"
Message received: "Message 3, pool-1-thread-1"
Message received: "Message 4, pool-1-thread-1"
Message received: "Message 5, pool-1-thread-1"
Message received: "Message 6, pool-1-thread-1"
Message received: "Message 7, pool-1-thread-1"
Message received: "Message 8, pool-1-thread-1"
Message received: "Message 9, pool-1-thread-1"
Message received: "Message 10, pool-1-thread-1"