redis订阅发布

一、简介

Pub/Sub 从字面上理解就是发布（Publish）与订阅（Subscribe），在Redis中，你可以设定对某一个key值进行消息发布及消息订阅，当一个key值上进行了消息发布后，所有订阅它的客户端都会收到相应的消息。这一功能最明显的用法就是构建实时消息系统，比如普通的即时聊天，群聊等功能

二、demo

2.1 订阅具体key

a连接上，订阅了 a1,a2,a3,三个key;

127.0.0.1:> SUBSCRIBE a1 a2 a3
Reading messages... (press Ctrl-C to quit)
) "subscribe"
) "a1"
) (integer)
) "subscribe"
) "a2"
) (integer)
) "subscribe"
) "a3"
) (integer)
) "message"
) "a1"
) "hello"
) "message"
) "a2"
) "jacky"
) "message"
) "a3"
) "aiai"

b连接，推送信息时，订阅的那端就能收到

127.0.0.1:> PUBLISH a1 hello
(integer)
127.0.0.1:> PUBLISH a2 jacky
(integer)
127.0.0.1:> PUBLISH a3 aiai
(integer)
127.0.0.1:> 

2.2 使用通配符来订阅

a连接, 订阅

[jacky@jacky bin]$ ./redis-cli -p
127.0.0.1:> PSUBSCRIBE new*
Reading messages... (press Ctrl-C to quit)
) "psubscribe"
) "new*"
) (integer)
) "pmessage"
) "new*"
) "new1"
) "haha"
) "pmessage"
) "new*"
) "new123"
) "wohaishihaha"

b连接 发布

[jacky@jacky bin]$ ./redis-cli -p
127.0.0.1:> PUBLISH new1 haha
(integer)
127.0.0.1:> PUBLISH new123 wohaishihaha
(integer)
127.0.0.1:>