六.消息的交换:direct类型的Exchange(通过消息的routing key比较queue的key)

向右看齐 2022-06-12 00:27 159阅读 0赞

根据routingKey匹配消息到符合的消费者消费消息

例:消费者1只消费info级别的日志，消费者2即消费info级别也消费error级别

生产者和消费者的pom.xml和上一章一样

**一.生产者Producer**  
1.发送Exchange类型为direct的消息的类:LogReceiveDirect.java

package com.rabbit.exchange;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import com.rabbitmq.client.Channel;
    import com.rabbitmq.client.Connection;
    import com.rabbitmq.client.ConnectionFactory;
    
    public class LogSenderDirect { 
    
    
        private Logger logger = LoggerFactory.getLogger(LogSenderFanout.class);
    
        //ConnectionFactory和Connection在正式开发时需要设置成单例
        private ConnectionFactory connectionFactory;
        private Connection connection;
        private Channel channel;
    
        /** * 在构造函数中获取连接 */
        public LogSenderDirect(){
            super();
            try {
                connectionFactory = new ConnectionFactory();
                connectionFactory.setHost("127.0.0.1");
                connection = connectionFactory.newConnection();
                channel = connection.createChannel();
            } catch (Exception e) {
                logger.error("获取连接时出错...");
            }
        }
    
        /** * 关闭连接的方法 */
        public boolean closeAll(){
            try {
                this.channel.close();
                this.connection.close();
            } catch (Exception e) {
                logger.error("关闭连接时异常...");
                return false;
            }
            return true;
        }
    
        /** * 发送消息到交换中心 */
        public void sendMessage(String message,String routingKey){
            try {
                //声明一个exchange,名字为logs,类型为direct
                channel.exchangeDeclare("logs", "direct");
                //发布消息到exchange上
                /** * 1.指定exchange的名字 * 2.direct类型 * 3.null... * 3.发送的消息 */
                channel.basicPublish("logs", routingKey, null, message.getBytes());
                logger.debug("发送direct类型的消息"+message+"到exchange交换中心.");
            } catch (Exception e) {
                logger.error("消息发送失败:"+e);
            }
        }
    
    }

2.启动测试的main方法:ExchangeDirectMain.java

package com.rabbit.main;
    
    import com.rabbit.exchange.LogSenderDirect;
    
    public class ExchangeDirectMain { 
    
        public static void main(String[] args) throws InterruptedException {
            LogSenderDirect logSender = new LogSenderDirect();
            //轮流每一秒发送info和error的消息(让消费者1接受info和error级别消息,消费者2只接受info级别消息)
            int i = 0;
            while (true) {
                if(i%2 == 0){
                    logSender.sendMessage("hello tiglle"+i+":info","info");
                }else{
                    logSender.sendMessage("hello tiglle"+i+":error","error");
                }
                Thread.sleep(1000);
                i++;
            }
        }
    
    }

**二.只消费info级别的Consumer**  
1.消费消息的类:LogReceiveDirect.java

package com.rabbit.exchange;
    
    import java.io.IOException;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import com.rabbitmq.client.AMQP;
    import com.rabbitmq.client.Channel;
    import com.rabbitmq.client.Connection;
    import com.rabbitmq.client.ConnectionFactory;
    import com.rabbitmq.client.Consumer;
    import com.rabbitmq.client.DefaultConsumer;
    import com.rabbitmq.client.Envelope;
    
    public class LogReceiveDirect { 
    
        private Logger logger = LoggerFactory.getLogger(LogReceiveDirect.class);
    
        //正式开发ConnectionFactory和Connection应该设置为单例
        private ConnectionFactory connectionFactory;
        private Connection connection;
        private Channel channel;
    
        /** * 在构造函数中获取连接 */
        public LogReceiveDirect(){
            super();//Objece为其父类...
            try {
                connectionFactory = new ConnectionFactory();
                connection  = connectionFactory.newConnection();
                channel = connection.createChannel();
                //声明exchange,防止生成者没启动的时候,exchange不存在(生成者和消费者总有一个要先声明)
                channel.exchangeDeclare("logs", "direct");
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
    
        /** * 关闭连接的方法 */
        public boolean closeAll(){
            try {
                this.channel.close();
                this.connection.close();
            } catch (Exception e) {
                logger.error("关闭连接异常:"+e);
                return false;
            }
            return true;
        }
    
        /** * 消费消息 */
        public void messageReceive(){
            try {
                //获取临时列队:自己声明队列是比较麻烦的，
                //因此，RabbitMQ提供了简便的获取临时队列的方法，该队列会在连接断开后销毁
                String queueName = channel.queueDeclare().getQueue();
                //把获取的临时列队绑定到logs这个exchange交换中心,只接受info级别日志
                /** * 1.列队名称 * 2.交换中心的名称 * 3.routingKey和生产者发布消息的时候指定的一样 */
                channel.queueBind(queueName, "logs", "info");
                //定义一个Consumer消费logs的消息
                Consumer consumer = new DefaultConsumer(channel) {
                    @Override
                    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,byte[] body) throws IOException {
                        // TODO Auto-generated method stub
                        String message = new String(body,"UTF-8");
                        logger.debug("我是打印日志的消费者:"+message);
                    }
                };
                //自动确认为true,接收到消息后该消息就销毁了
                channel.basicConsume(queueName, true, consumer);
            } catch (Exception e) {
                logger.error("消费消息时异常:"+e);
            }
        }
    }

2.启动监听的main方法:ExchangeDirectMain.java

package com.rabbit.main;
    
    import com.rabbit.exchange.LogReceiveDirect;
    
    public class ExchangeDirectMain { 
    
        public static void main(String[] args) {
            LogReceiveDirect logReceive = new LogReceiveDirect();
            logReceive.messageReceive();
        }
    
    }

**三.同时消费info和error级别消息的消费者**  
1.消费消息的类:LogReceiveDirect.java

package com.rabbit.exchange;
    
    import java.io.IOException;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import com.rabbitmq.client.AMQP;
    import com.rabbitmq.client.Channel;
    import com.rabbitmq.client.Connection;
    import com.rabbitmq.client.ConnectionFactory;
    import com.rabbitmq.client.Consumer;
    import com.rabbitmq.client.DefaultConsumer;
    import com.rabbitmq.client.Envelope;
    
    public class LogReceiveDirect { 
    
        private Logger logger = LoggerFactory.getLogger(LogReceiveDirect.class);
    
        //正式开发ConnectionFactory和Connection应该设置为单例
        private ConnectionFactory connectionFactory;
        private Connection connection;
        private Channel channel;
    
        /** * 在构造函数中获取连接 */
        public LogReceiveDirect(){
            super();//Objece为其父类...
            try {
                connectionFactory = new ConnectionFactory();
                connection  = connectionFactory.newConnection();
                channel = connection.createChannel();
                //声明exchange,防止生成者没启动的时候,exchange不存在(生成者和消费者总有一个要先声明)
                channel.exchangeDeclare("logs", "direct");
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
    
        /** * 关闭连接的方法 */
        public boolean closeAll(){
            try {
                this.channel.close();
                this.connection.close();
            } catch (Exception e) {
                logger.error("关闭连接异常:"+e);
                return false;
            }
            return true;
        }
    
        /** * 消费消息 */
        public void messageReceive(){
            try {
                //获取临时列队:自己声明队列是比较麻烦的，
                //因此，RabbitMQ提供了简便的获取临时队列的方法，该队列会在连接断开后销毁
                String queueName = channel.queueDeclare().getQueue();
                //把获取的临时列队绑定到logs这个exchange交换中心,绑定两个routingKey(同时接受info和error级别日志),不会覆盖
                /** * 1.列队名称 * 2.交换中心的名称 * 3.routingKey和生产者发布消息的时候指定的一样 */
                channel.queueBind(queueName, "logs", "info");
                channel.queueBind(queueName, "logs", "error");
                //定义一个Consumer消费logs的消息
                Consumer consumer = new DefaultConsumer(channel) {
                    @Override
                    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,byte[] body) throws IOException {
                        // TODO Auto-generated method stub
                        String message = new String(body,"UTF-8");
                        logger.debug("我是写硬盘的消费者:"+message);
                    }
                };
                //自动确认为true,接收到消息后该消息就销毁了
                channel.basicConsume(queueName, true, consumer);
            } catch (Exception e) {
                logger.error("消费消息时异常:"+e);
            }
        }
    }

2.启动监听的main方法:ExchangeDirectMain.java

这时，提供者的info级别日志会被消费者1和消费者2同时消费，error级别的日志只会被消费者2消费