RabbitMQ基础教程之基本使用篇
RabbitMQ基础教程之基本使用篇
最近因为工作原因使用到RabbitMQ,之前也接触过其他的mq消息中间件,从实际使用感觉来看,却不太一样,正好趁着周末,可以好好看一下RabbitMQ的相关知识点;希望可以通过一些学习,可以搞清楚以下几点
- 基础环境搭建
- 可以怎么使用
- 实现原理是怎样的
- 实际工程中的使用(比如结合SpringBoot可以怎么玩)
相关博文,欢迎查看:
I. 前提准备
在开始之前,先得搭建基本的环境,因为个人主要是mac进行的开发,所有写了一篇mac上如何安装rabbitmq的教程,可以通过 《mac下安装和测试rabbitmq》 查看
1. Centos安装过程
下面简单说一下Linux系统下,可以如何安装
Centos 系统:
# 安装erlang
rpm -Uvh http://download.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-8.noarch.rpm
yum install erlang
# 安装RabbitMQ
wget http://www.rabbitmq.com/releases/rabbitmq-server/v3.6.6/rabbitmq-server-3.6.6-1.el7.noarch.rpm
yum install rabbitmq-server-3.6.6-1.el7.noarch.rpm
启动和查看的命令
# 完成后启动服务:
service rabbitmq-server start
# 可以查看服务状态:
service rabbitmq-server status
2. 注意
- 安装完毕之后,可以开启控制台,主要就是
rabbitmq-plugins enable rabbitmq_management
, 默认的端口号为15672 - 默认分配的用户/密码为: guest/guest, 只允许本地访问;如果跨应用读写数据时,请添加账号和设置对应的权限(推荐参考上面mac安装的博文,里面有介绍)
II. 基本使用篇
直接使用amqp-client客户端做基本的数据读写,先不考虑Spring容器的场景,我们可以怎样进行塞数据,然后又怎样可以从里面获取数据;
在实际使用之前,有必要了解一下RabbitMQ的几个基本概念,即什么是Queue,Exchange,Binding,关于这些基本概念,可以参考博文:
1. 基本使用姿势
首先是建立连接,一般需要设置服务器的IP,端口号,用户名密码之类的,公共代码如下
public class RabbitUtil {
public static ConnectionFactory getConnectionFactory() {
//创建连接工程,下面给出的是默认的case
ConnectionFactory factory = new ConnectionFactory();
factory.setHost("127.0.0.1");
factory.setPort(5672);
factory.setUsername("admin");
factory.setPassword("admin");
factory.setVirtualHost("/");
return factory;
}
}
a. 生产者
要使用,基本的就需要一个消息投递和一个消息消费两方,线看消息生产者的一般写法
public class MsgProducer {
public static void publishMsg(String exchange, BuiltinExchangeType exchangeType, String toutingKey, String message)
throws IOException, TimeoutException {
ConnectionFactory factory = RabbitUtil.getConnectionFactory();
//创建连接
Connection connection = factory.newConnection();
//创建消息通道
Channel channel = connection.createChannel();
// 声明exchange中的消息为可持久化,不自动删除
channel.exchangeDeclare(exchange, exchangeType, true, false, null);
// 发布消息
channel.basicPublish(exchange, toutingKey, null, message.getBytes());
channel.close();
connection.close();
}
}
针对上面的代码,结合RabbitMQ的基本概念进行分析
![](https://upload-images.jianshu.io/upload_images/1405936-39c21c25c60518ac.jpg?imageMogr2/auto-orient/strip%7CimageView2/2/w/700)
- 不管是干啥,第一步都是获取连接,也就是上面的Connection
- 从《RabbitMq基础教程之基本概念》直到,生产者消费者都是借助Channel与Exchange或者Queue打交道,接下来就是通过Connection创建数据流通信道Channel
- Channel准备完毕之后,生产者就可以向其中投递数据
- 投递完毕之后,回收现场资源
疑问:
- 在声明Exchange时,是否就需要选择消息绑定策略?
- 不声明时,默认是什么策略?
b. 消费者
结合上面的代码和分析,大胆的预测下消费者的流程
- 获取连接Connection
- 创建Channel
- 将Channel与Queue进行绑定
- 创建一个Consumer,从Queue中获取数据
- 消息消费之后,ack
下面给出一个mq推数据的消费过程
public class MsgConsumer {
public static void consumerMsg(String exchange, String queue, String routingKey)
throws IOException, TimeoutException {
ConnectionFactory factory = RabbitUtil.getConnectionFactory();
//创建连接
Connection connection = factory.newConnection();
//创建消息信道
final Channel channel = connection.createChannel();
//消息队列
channel.queueDeclare(queue, true, false, false, null);
//绑定队列到交换机
channel.queueBind(queue, exchange, routingKey);
System.out.println("[*] Waiting for message. To exist press CTRL+C");
Consumer consumer = new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
byte[] body) throws IOException {
String message = new String(body, "UTF-8");
try {
System.out.println(" [x] Received '" + message);
} finally {
System.out.println(" [x] Done");
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
};
// 取消自动ack
channel.basicConsume(queue, false, consumer);
}
}
2. Direct方式
a. Producer
直接在前面的基础上进行测试,我们定义一个新的exchange名为direct.exchange
,并且制定ExchangeType为直接路由方式 (先不管这种写法的合理性)
public class DirectProducer {
private static final String EXCHANGE_NAME = "direct.exchange";
public void publishMsg(String routingKey, String msg) {
try {
MsgProducer.publishMsg(EXCHANGE_NAME, BuiltinExchangeType.DIRECT, routingKey, msg);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
DirectProducer directProducer = new DirectProducer();
String[] routingKey = new String[]{"aaa", "bbb"};
String msg = "hello >>> ";
for (int i = 0; i < 30; i++) {
directProducer.publishMsg(routingKey[i % 2], msg + i);
}
System.out.println("----over-------");
}
}
上面的代码执行一遍之后,看控制台会发现新增了一个Exchange
![](https://upload-images.jianshu.io/upload_images/1405936-f891d8e096cfa24e.jpg?imageMogr2/auto-orient/strip%7CimageView2/2/w/700)
b. consumer
同样的我们写一下对应的消费者,一个用来消费aaa,一个消费bbb
public class DirectConsumer {
private static final String exchangeName = "direct.exchange";
public void msgConsumer(String queueName, String routingKey) {
try {
MsgConsumer.consumerMsg(exchangeName, queueName, routingKey);
} catch (IOException e) {
e.printStackTrace();
} catch (TimeoutException e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws InterruptedException {
DirectConsumer consumer = new DirectConsumer();
String[] routingKey = new String[]{"aaa", "bbb"};
String[] queueNames = new String[]{"qa", "qb"};
for (int i = 0; i < 2; i++) {
consumer.msgConsumer(queueNames[i], routingKey[i]);
}
Thread.sleep(1000 * 60 * 10);
}
}
执行上面的代码之后,就会多两个Queue,且增加了Exchange到Queue的绑定
![](https://upload-images.jianshu.io/upload_images/1405936-e8ea3bf49fbbccbe.jpg?imageMogr2/auto-orient/strip%7CimageView2/2/w/700)
![](https://upload-images.jianshu.io/upload_images/1405936-fb496674685f50ac.jpg?imageMogr2/auto-orient/strip%7CimageView2/2/w/700)
当上面两个代码配合起来使用时,就可以看到对于消费者而言,qa一直消费的是偶数,qb一直消费的是奇数,一次输出如下:
[qa] Waiting for message. To exist press CTRL+C
[qb] Waiting for message. To exist press CTRL+C
[qa] Received 'hello >>> 0
[qb] Received 'hello >>> 1
[qa] Received 'hello >>> 2
[qb] Received 'hello >>> 3
[qa] Received 'hello >>> 4
...
3. Fanout方式
有了上面的case之后,这个的实现和测试就比较简单了
a. Producer
public class FanoutProducer {
private static final String EXCHANGE_NAME = "fanout.exchange";
public void publishMsg(String routingKey, String msg) {
try {
MsgProducer.publishMsg(EXCHANGE_NAME, BuiltinExchangeType.FANOUT, routingKey, msg);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
FanoutProducer directProducer = new FanoutProducer();
String[] routingKey = new String[]{"aaa", "bbb"};
String msg = "hello >>> ";
for (int i = 0; i < 30; i++) {
directProducer.publishMsg(routingKey[i % 2], msg + i);
}
System.out.println("----over-------");
}
}
b. consumer
public class FanoutProducer {
private static final String EXCHANGE_NAME = "fanout.exchange";
public void publishMsg(String routingKey, String msg) {
try {
MsgProducer.publishMsg(EXCHANGE_NAME, BuiltinExchangeType.FANOUT, routingKey, msg);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
FanoutProducer directProducer = new FanoutProducer();
String[] routingKey = new String[]{"aaa", "bbb"};
String msg = "hello >>> ";
for (int i = 0; i < 30; i++) {
directProducer.publishMsg(routingKey[i % 2], msg + i);
}
System.out.println("----over-------");
}
}
这个的输出就比较有意思了,fa,fb两个队列都可以接收到发布的消息,而且单独的执行一次上面的投递数据之后,发现fa/fb两个队列的数据都是30条
![](https://upload-images.jianshu.io/upload_images/1405936-fac7e8c5cddb967d.jpg?imageMogr2/auto-orient/strip%7CimageView2/2/w/700)
然后消费的结果如下
[qa] Waiting for message. To exist press CTRL+C
[qb] Waiting for message. To exist press CTRL+C
[qa] Received 'hello >>> 0
[qb] Received 'hello >>> 0
[qa] Received 'hello >>> 1
[qb] Received 'hello >>> 1
[qb] Received 'hello >>> 2
[qa] Received 'hello >>> 2
[qa] Received 'hello >>> 3
[qb] Received 'hello >>> 3
[qb] Received 'hello >>> 4
[qa] Received 'hello >>> 4
...
4. Topic方式
代码和上面差不多,就不重复拷贝了,接下来卡另外几个问题
III. 基础进阶
在上面的基础使用中,会有几个疑问如下:
- Exchange声明的问题(是否必须声明,如果不声明会怎样)
- Exchange声明的几个参数(durable, autoDelete)有啥区别
- 当没有队列和Exchange绑定时,直接往队列中塞数据,好像不会有数据增加(即先塞数据,然后创建queue,建立绑定,从控制台上看这个queue里面也不会有数据)
- 消息消费的两种姿势(一个主动去拿数据,一个是rabbit推数据)对比
- ack/nack怎么用,nack之后消息可以怎么处理
以上内容,留待下一篇进行讲解
IV. 其他
1. 相关博文
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