rabbitmq channel参数详解【转】

 

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。
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 /*** Declare an exchange.* @see com.rabbitmq.client.AMQP.Exchange.Declare* @see com.rabbitmq.client.AMQP.Exchange.DeclareOk* @param exchange the name of the exchange* @param type the exchange type* @param durable true if we are declaring a durable exchange (the exchange will survive a server restart)* @param autoDelete true if the server should delete the exchange when it is no longer in use* @param arguments other properties (construction arguments) for the exchange* @return a declaration-confirm method to indicate the exchange was successfully declared* @throws java.io.IOException if an error is encountered*/Exchange.DeclareOk exchangeDeclare(String exchange, String type, boolean durable, boolean autoDelete,Map<String, Object> arguments) throws IOException;
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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：true\false 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
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    /*** Request specific "quality of service" settings.** These settings impose limits on the amount of data the server* will deliver to consumers before requiring acknowledgements.* Thus they provide a means of consumer-initiated flow control.* @see com.rabbitmq.client.AMQP.Basic.Qos* @param prefetchSize maximum amount of content (measured in* octets) that the server will deliver, 0 if unlimited* @param prefetchCount maximum number of messages that the server* will deliver, 0 if unlimited* @param global true if the settings should be applied to the* entire channel rather than each consumer* @throws java.io.IOException if an error is encountered*/void basicQos(int prefetchSize, int prefetchCount, boolean global) throws IOException;
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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。
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  /*** Publish a message.** Publishing to a non-existent exchange will result in a channel-level* protocol exception, which closes the channel.** Invocations of <code>Channel#basicPublish</code> will eventually block if a* <a href="http://www.rabbitmq.com/alarms.html">resource-driven alarm</a> is in effect.** @see com.rabbitmq.client.AMQP.Basic.Publish* @see <a href="http://www.rabbitmq.com/alarms.html">Resource-driven alarms</a>.* @param exchange the exchange to publish the message to* @param routingKey the routing key* @param mandatory true if the 'mandatory' flag is to be set* @param immediate true if the 'immediate' flag is to be* set. Note that the RabbitMQ server does not support this flag.* @param props other properties for the message - routing headers etc* @param body the message body* @throws java.io.IOException if an error is encountered*/void basicPublish(String exchange, String routingKey, boolean mandatory, boolean immediate, BasicProperties props, byte[] body)throws IOException;
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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。

 

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    /*** Acknowledge one or several received* messages. Supply the deliveryTag from the {@link com.rabbitmq.client.AMQP.Basic.GetOk}* or {@link com.rabbitmq.client.AMQP.Basic.Deliver} method* containing the received message being acknowledged.* @see com.rabbitmq.client.AMQP.Basic.Ack* @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver}* @param multiple true to acknowledge all messages up to and* including the supplied delivery tag; false to acknowledge just* the supplied delivery tag.* @throws java.io.IOException if an error is encountered*/void basicAck(long deliveryTag, boolean multiple) throws IOException;
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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

 

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    /*** Reject one or several received messages.** Supply the <code>deliveryTag</code> from the {@link com.rabbitmq.client.AMQP.Basic.GetOk}* or {@link com.rabbitmq.client.AMQP.Basic.GetOk} method containing the message to be rejected.* @see com.rabbitmq.client.AMQP.Basic.Nack* @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver}* @param multiple true to reject all messages up to and including* the supplied delivery tag; false to reject just the supplied* delivery tag.* @param requeue true if the rejected message(s) should be requeued rather* than discarded/dead-lettered* @throws java.io.IOException if an error is encountered*/void basicNack(long deliveryTag, boolean multiple, boolean requeue)throws IOException;
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1.5 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

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 /*** Reject a message. Supply the deliveryTag from the {@link com.rabbitmq.client.AMQP.Basic.GetOk}* or {@link com.rabbitmq.client.AMQP.Basic.Deliver} method* containing the received message being rejected.* @see com.rabbitmq.client.AMQP.Basic.Reject* @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver}* @param requeue true if the rejected message should be requeued rather than discarded/dead-lettered* @throws java.io.IOException if an error is encountered*/void basicReject(long deliveryTag, boolean requeue) throws IOException;
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1.6 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
 
 
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    /*** Start a non-nolocal, non-exclusive consumer, with* a server-generated consumerTag.* @param queue the name of the queue* @param autoAck true if the server should consider messages* acknowledged once delivered; false if the server should expect* explicit acknowledgements* @param callback an interface to the consumer object* @return the consumerTag generated by the server* @throws java.io.IOException if an error is encountered* @see com.rabbitmq.client.AMQP.Basic.Consume* @see com.rabbitmq.client.AMQP.Basic.ConsumeOk* @see #basicConsume(String, boolean, String, boolean, boolean, Map, Consumer)*/String basicConsume(String queue, boolean autoAck, Consumer callback) throws IOException;
 
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1.7 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
 
 
 
 
 
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    /*** Bind an exchange to an exchange, with no extra arguments.* @see com.rabbitmq.client.AMQP.Exchange.Bind* @see com.rabbitmq.client.AMQP.Exchange.BindOk* @param destination the name of the exchange to which messages flow across the binding* @param source the name of the exchange from which messages flow across the binding* @param routingKey the routine key to use for the binding* @return a binding-confirm method if the binding was successfully created* @throws java.io.IOException if an error is encountered*/Exchange.BindOk exchangeBind(String destination, String source, String routingKey) throws IOException;
 
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1.8 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.
 
 
 
 
 
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 /*** Declare a queue* @see com.rabbitmq.client.AMQP.Queue.Declare* @see com.rabbitmq.client.AMQP.Queue.DeclareOk* @param queue the name of the queue* @param durable true if we are declaring a durable queue (the queue will survive a server restart)* @param exclusive true if we are declaring an exclusive queue (restricted to this connection)* @param autoDelete true if we are declaring an autodelete queue (server will delete it when no longer in use)* @param arguments other properties (construction arguments) for the queue* @return a declaration-confirm method to indicate the queue was successfully declared* @throws java.io.IOException if an error is encountered*/Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete,Map<String, Object> arguments) throws IOException;
 
 
 
 
转：https://www.cnblogs.com/piaolingzxh/p/5448927.html
 
 


 

转载于:https://www.cnblogs.com/royfans/p/9628924.html




    











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