NodeJS操作Redis实现消息的发布与订阅

首先先说一下流程：

1.保存数据到Redis，然后将member值publish到 chat频道（publish.js功能）

2.readRedis.js文件此前一直在监听chat频道，readRedis.js文件接收到member后，用它作为条件去Redis中去查找，拿到score数据

代码如下：

publish.js文件：

var redis = require("redis");
var client = redis.createClient(6379, "127.0.0.1");function zadd(key, score, member) {
    client.zadd(key, score, member, function () {
        client.publish("chat", member);//client将member发布到chat这个频道
        //然后订阅这个频道的订阅者就会收到消息
    });
}
for (var i = 0; i < 10; i++) {
    zadd("z", i, "" + i);//发布10次
    console.log("第" + i + "次");
}

readRedis.js文件：

var redis = require("redis");
var client = redis.createClient(6379, "127.0.0.1");
var client1 = redis.createClient(6379, "127.0.0.1");function getRedisData() {
    //客户端连接redis成功后执行回调
    client.on("ready", function () {
        //订阅消息
        client.subscribe("chat");
        client.subscribe("chat1");
        console.log("订阅成功。。。");
    });    client.on("error", function (error) {
        console.log("Redis Error " + error);
    });    //监听订阅成功事件
    client.on("subscribe", function (channel, count) {
        console.log("client subscribed to " + channel + "," + count + "total subscriptions");
    });    //收到消息后执行回调，message是redis发布的消息
    client.on("message", function (channel, message) {
        console.log("我接收到信息了" + message);
        dealWithMsg(message);
    });    //监听取消订阅事件
    client.on("unsubscribe", function (channel, count) {
        console.log("client unsubscribed from" + channel + ", " + count + " total subscriptions")
    });
}function dealWithMsg(message) {
    //按照message查询内容
    client1.zscore("z", message, function (err, reply) {
        console.log(message + "的内容是：" + reply);
    });
}
getRedisData();  

当publish的内容为对象的时候，要把对象转化成Buffer类型，例如：

function publishRegisterResult(responseBody) {
    responseBody = {
        name: "lw",
        age: 30
    };
    var bufferBody = new Buffer(JSON.stringify(responseBody), 'utf8');
    redis.ac_register_redis.publish(config.redis_prefix.special_register_result, bufferBody, function (err, result) {
        if (err) {
            console.log("publish register result error: ", err.toString());
        } else {
            console.log("publish register result success");
        }
    });
}

注意， 只要客户端订阅了频道， 除了SUBCRIBE,UNSUBCRIBE,PSUBCRIBE,PSUBCRIBE，就不能执行其他命令。

参考：http://wiki.jikexueyuan.com/project/redis/subscribe-to-release-mechanism.html