1.Channel
1.1 channel.exchangeDeclare():
type:有direct、fanout、topic三种
durable:true、false true:服务器重启会保留下来Exchange。警告:仅设置此选项,不代表消息持久化。即不保证重启后消息还在。原文:true if we are declaring a durable exchange (the exchange will survive a server restart)
autoDelete:true、false.true:当已经没有消费者时,服务器是否可以删除该Exchange。原文1:true if the server should delete the exchange when it is no longer in use。
1 /** 2 * Declare an exchange. 3 * @see com.rabbitmq.client.AMQP.Exchange.Declare 4 * @see com.rabbitmq.client.AMQP.Exchange.DeclareOk 5 * @param exchange the name of the exchange 6 * @param type the exchange type 7 * @param durable true if we are declaring a durable exchange (the exchange will survive a server restart) 8 * @param autoDelete true if the server should delete the exchange when it is no longer in use 9 * @param arguments other properties (construction arguments) for the exchange 10 * @return a declaration-confirm method to indicate the exchange was successfully declared 11 * @throws java.io.IOException if an error is encountered 12 */ 13 Exchange.DeclareOk exchangeDeclare(String exchange, String type, boolean durable, boolean autoDelete, 14 Map<String, Object> arguments) throws IOException;
1.2 chanel.basicQos()
prefetchSize:0
prefetchCount:会告诉RabbitMQ不要同时给一个消费者推送多于N个消息,即一旦有N个消息还没有ack,则该consumer将block掉,直到有消息ack
global:truefalse 是否将上面设置应用于channel,简单点说,就是上面限制是channel级别的还是consumer级别
备注:据说prefetchSize 和global这两项,rabbitmq没有实现,暂且不研究
1 /** 2 * Request specific "quality of service" settings. 3 * 4 * These settings impose limits on the amount of data the server 5 * will deliver to consumers before requiring acknowledgements. 6 * Thus they provide a means of consumer-initiated flow control. 7 * @see com.rabbitmq.client.AMQP.Basic.Qos 8 * @param prefetchSize maximum amount of content (measured in 9 * octets) that the server will deliver, 0 if unlimited 10 * @param prefetchCount maximum number of messages that the server 11 * will deliver, 0 if unlimited 12 * @param global true if the settings should be applied to the 13 * entire channel rather than each consumer 14 * @throws java.io.IOException if an error is encountered 15 */ 16 void basicQos(int prefetchSize, int prefetchCount, boolean global) throws IOException;
1.3 channel.basicPublish()
routingKey:路由键,#匹配0个或多个单词,*匹配一个单词,在topic exchange做消息转发用
mandatory:true:如果exchange根据自身类型和消息routeKey无法找到一个符合条件的queue,那么会调用basic.return方法将消息返还给生产者。false:出现上述情形broker会直接将消息扔掉
immediate:true:如果exchange在将消息route到queue(s)时发现对应的queue上没有消费者,那么这条消息不会放入队列中。当与消息routeKey关联的所有queue(一个或多个)都没有消费者时,该消息会通过basic.return方法返还给生产者。
BasicProperties :需要注意的是BasicProperties.deliveryMode,0:不持久化 1:持久化 这里指的是消息的持久化,配合channel(durable=true),queue(durable)可以实现,即使服务器宕机,消息仍然保留
简单来说:mandatory标志告诉服务器至少将该消息route到一个队列中,否则将消息返还给生产者;immediate标志告诉服务器如果该消息关联的queue上有消费者,则马上将消息投递给它,如果所有queue都没有消费者,直接把消息返还给生产者,不用将消息入队列等待消费者了。
1 /** 2 * Publish a message. 3 * 4 * Publishing to a non-existent exchange will result in a channel-level 5 * protocol exception, which closes the channel. 6 * 7 * Invocations of <code>Channel#basicPublish</code> will eventually block if a 8 * <a href="http://www.rabbitmq.com/alarms.html">resource-driven alarm</a> is in effect. 9 * 10 * @see com.rabbitmq.client.AMQP.Basic.Publish 11 * @see <a href="http://www.rabbitmq.com/alarms.html">Resource-driven alarms</a>. 12 * @param exchange the exchange to publish the message to 13 * @param routingKey the routing key 14 * @param mandatory true if the 'mandatory' flag is to be set 15 * @param immediate true if the 'immediate' flag is to be 16 * set. Note that the RabbitMQ server does not support this flag. 17 * @param props other properties for the message - routing headers etc 18 * @param body the message body 19 * @throws java.io.IOException if an error is encountered 20 */ 21 void basicPublish(String exchange, String routingKey, boolean mandatory, boolean immediate, BasicProperties props, byte[] body) 22 throws IOException;
1.4 channel.basicAck();
deliveryTag:该消息的index
multiple:是否批量.true:将一次性ack所有小于deliveryTag的消息。
1 /** 2 * Acknowledge one or several received 3 * messages. Supply the deliveryTag from the {@link com.rabbitmq.client.AMQP.Basic.GetOk} 4 * or {@link com.rabbitmq.client.AMQP.Basic.Deliver} method 5 * containing the received message being acknowledged. 6 * @see com.rabbitmq.client.AMQP.Basic.Ack 7 * @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver} 8 * @param multiple true to acknowledge all messages up to and 9 * including the supplied delivery tag; false to acknowledge just 10 * the supplied delivery tag. 11 * @throws java.io.IOException if an error is encountered 12 */ 13 void basicAck(long deliveryTag, boolean multiple) throws IOException;
1.5 channel.basicNack(delivery.getEnvelope().getDeliveryTag(), false, true);
deliveryTag:该消息的index
multiple:是否批量.true:将一次性拒绝所有小于deliveryTag的消息。
requeue:被拒绝的是否重新入队列
1 /** 2 * Reject one or several received messages. 3 * 4 * Supply the <code>deliveryTag</code> from the {@link com.rabbitmq.client.AMQP.Basic.GetOk} 5 * or {@link com.rabbitmq.client.AMQP.Basic.GetOk} method containing the message to be rejected. 6 * @see com.rabbitmq.client.AMQP.Basic.Nack 7 * @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver} 8 * @param multiple true to reject all messages up to and including 9 * the supplied delivery tag; false to reject just the supplied 10 * delivery tag. 11 * @param requeue true if the rejected message(s) should be requeued rather 12 * than discarded/dead-lettered 13 * @throws java.io.IOException if an error is encountered 14 */ 15 void basicNack(long deliveryTag, boolean multiple, boolean requeue) 16 throws IOException;
1.6 channel.basicReject(delivery.getEnvelope().getDeliveryTag(), false);
deliveryTag:该消息的index
requeue:被拒绝的是否重新入队列
channel.basicNack 与 channel.basicReject 的区别在于basicNack可以拒绝多条消息,而basicReject一次只能拒绝一条消息
1 /** 2 * Reject a message. Supply the deliveryTag from the {@link com.rabbitmq.client.AMQP.Basic.GetOk} 3 * or {@link com.rabbitmq.client.AMQP.Basic.Deliver} method 4 * containing the received message being rejected. 5 * @see com.rabbitmq.client.AMQP.Basic.Reject 6 * @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver} 7 * @param requeue true if the rejected message should be requeued rather than discarded/dead-lettered 8 * @throws java.io.IOException if an error is encountered 9 */ 10 void basicReject(long deliveryTag, boolean requeue) throws IOException;
1.7 channel.basicConsume(QUEUE_NAME, true, consumer);
autoAck:是否自动ack,如果不自动ack,需要使用channel.ack、channel.nack、channel.basicReject 进行消息应答
1 /** 2 * Start a non-nolocal, non-exclusive consumer, with 3 * a server-generated consumerTag. 4 * @param queue the name of the queue 5 * @param autoAck true if the server should consider messages 6 * acknowledged once delivered; false if the server should expect 7 * explicit acknowledgements 8 * @param callback an interface to the consumer object 9 * @return the consumerTag generated by the server 10 * @throws java.io.IOException if an error is encountered 11 * @see com.rabbitmq.client.AMQP.Basic.Consume 12 * @see com.rabbitmq.client.AMQP.Basic.ConsumeOk 13 * @see #basicConsume(String, boolean, String, boolean, boolean, Map, Consumer) 14 */ 15 String basicConsume(String queue, boolean autoAck, Consumer callback) throws IOException;
1.8 chanel.exchangeBind()
channel.queueBind(queueName, EXCHANGE_NAME, bindingKey);
用于通过绑定bindingKey将queue到Exchange,之后便可以进行消息接收
1 /** 2 * Bind an exchange to an exchange, with no extra arguments. 3 * @see com.rabbitmq.client.AMQP.Exchange.Bind 4 * @see com.rabbitmq.client.AMQP.Exchange.BindOk 5 * @param destination the name of the exchange to which messages flow across the binding 6 * @param source the name of the exchange from which messages flow across the binding 7 * @param routingKey the routine key to use for the binding 8 * @return a binding-confirm method if the binding was successfully created 9 * @throws java.io.IOException if an error is encountered 10 */ 11 Exchange.BindOk exchangeBind(String destination, String source, String routingKey) throws IOException;
1.9 channel.queueDeclare(QUEUE_NAME, false, false, false, null);
durable:true、false true:在服务器重启时,能够存活
exclusive :是否为当前连接的专用队列,在连接断开后,会自动删除该队列,生产环境中应该很少用到吧。
autodelete:当没有任何消费者使用时,自动删除该队列。this means that the queue will be deleted when there are no more processes consuming messages from it.
1 /** 2 * Declare a queue 3 * @see com.rabbitmq.client.AMQP.Queue.Declare 4 * @see com.rabbitmq.client.AMQP.Queue.DeclareOk 5 * @param queue the name of the queue 6 * @param durable true if we are declaring a durable queue (the queue will survive a server restart) 7 * @param exclusive true if we are declaring an exclusive queue (restricted to this connection) 8 * @param autoDelete true if we are declaring an autodelete queue (server will delete it when no longer in use) 9 * @param arguments other properties (construction arguments) for the queue 10 * @return a declaration-confirm method to indicate the queue was successfully declared 11 * @throws java.io.IOException if an error is encountered 12 */ 13 Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete, 14 Map<String, Object> arguments) throws IOException;
参考:http://blog.csdn.net/jiao_fuyou/article/details/21594947