rabbitmq direct、fanout、topic 三种Exchange java 代码比较

Producer端

1、channel的创建

　　无论是才用什么样的Exchange，创建channel代码都是相同的，如下

 ConnectionFactory factory = new ConnectionFactory();
 factory.setHost("localhost");
 Connection connection = factory.newConnection();
 Channel channel = connection.createChannel();

2、Exchange的创建

　2.1 direct

　　direct使用默认的Exchange，不需要声明，单需要指定消息发送到那个队列

channel.queueDeclare(QUEUE_NAME, false, false, false, null);

　2.2 fanout

channel.exchangeDeclare(EXCHANGE_NAME, "fanout")

　2.3 topic如下

channel.exchangeDeclare(EXCHANGE_NAME, "topic");

3、消息的发送

  3.1 direct

channel.basicPublish("", QUEUE_NAME, null, message.getBytes());

3.2 fanout

channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes());

3.3 topic

channel.basicPublish(EXCHANGE_NAME, routingKey, null, message.getBytes());

cusumer端

1、创建channel

ConnectionFactory factory = new ConnectionFactory();
factory.setHost("localhost");
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();

2、消息前的准备

2.1  direct直接绑定队列进行消息的消费

chanel.queueDeclare(QUEUE_NAME, false, false, false, null);

2.2 fanout，需要先指定exchange类型为fanout

channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
String queueName = channel.queueDeclare().getQueue();
channel.queueBind(queueName, EXCHANGE_NAME, "");

2.3 topic

channel.exchangeDeclare(EXCHANGE_NAME, "topic");
String queueName = channel.queueDeclare().getQueue();
 for(String bindingKey : argv){
      channel.queueBind(queueName, EXCHANGE_NAME, bindingKey);
 }

3、具体消费消息的代码是一样的

QueueingConsumer consumer = new QueueingConsumer(channel);
channel.basicConsume(QUEUE_NAME, true, consumer);
while (true) {
    QueueingConsumer.Delivery delivery = consumer.nextDelivery();
    Envelope elp = delivery.getEnvelope();
    String message = new String(delivery.getBody());
    System.out.println(" [x] Received '" + message + "'");
    channel.basicAck(elp.getDeliveryTag(), false);
    //channel.basicNack();
​}