RabbitMQ案例之Publish/Subscribe

目的：把消息发到每一个消费者

如上图。在producer与queue之间还有一个交换机(exchange),producer把消息发送到exchange上，消费都拿着queue来bind到exchang上后。当producer发布消息时，consumer都可以收到信息。

EmitLog.java发日志：

package yy.rabbitstudy.publish;import java.io.IOException;import java.util.concurrent.TimeoutException;import org.omg.CORBA.PRIVATE_MEMBER;import org.springframework.amqp.core.ExchangeTypes;import com.rabbitmq.client.Channel;import com.rabbitmq.client.Connection;import com.rabbitmq.client.ConnectionFactory;public class EmitLog {        private static final String EXCHANGE_NAME="logs";    public static void main(String[] args) {        Connection connection=null;        Channel channel =null;        try{                        args=new String[]{"FirstMessage..","SecondMessage...","ThirdMessage..","FourthMessage..","FifthMessage...","6Message...","7Message...","8Message...","9Message...","10Message..."};            ConnectionFactory factory=new ConnectionFactory();            factory.setHost("localhost");            connection=factory.newConnection();            channel = connection.createChannel();            channel.exchangeDeclare(EXCHANGE_NAME, ExchangeTypes.FANOUT);            System.out.println(channel.queueDeclare().getQueue());            for (String string : args) {                                String message = getMessage(new String[]{string});                //把消息发到exchange上                channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes());                System.out.println("[x] Sent" + message + "");            }        }catch(Exception e){                    }finally {            if(channel!=null){                try {                    channel.close();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                } catch (TimeoutException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }            if(connection!=null){                try {                    connection.close();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        }    }    private static String getMessage(String[] strings){        if(strings.length<1)return "Hello World";        return joinString(strings, " ");    }        private static String joinString(String[] strings,String delimiter){        int length=strings.length;        if(length==0)return "";        StringBuilder words=new StringBuilder(strings[0]);        for(int i=1;i<length;i++){            words.append(delimiter).append(strings[i]);        }        return words.toString();    }}

ReceiveLogs.java 是收日志的浪费者

package yy.rabbitstudy.publish;import java.io.IOException;import java.util.concurrent.TimeoutException;import org.springframework.amqp.core.ExchangeTypes;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 ReceiveLogs {    private final static String EXCHANGE_NAME ="logs";    public static void main(String[] args) throws IOException, TimeoutException {                ConnectionFactory factory=new ConnectionFactory();        factory.setHost("localhost");        Connection connection=factory.newConnection();        Channel channel=connection.createChannel();        channel.exchangeDeclare(EXCHANGE_NAME, ExchangeTypes.FANOUT);        String queueName=channel.queueDeclare().getQueue();        System.out.println("[*] Waiting for messages. to exit press CTRL+C  "+queueName);                channel.queueBind(queueName, EXCHANGE_NAME, "");        //把通道交给消费者        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");              System.out.println(" [x] Received '" + message + "'");            }          };          boolean autoAck=true;//当autoAck为false的时候，当消费都收到信息后，会回复队列，我收到信息了。这样就不会造成队列的消息流失。          channel.basicConsume(queueName, autoAck, consumer);    }    }