RabbitMQ-01-每一步都是坑

01：主机无法访问虚拟机MQ查询指定端口是否已开firewall-cmd --query-port=15672/tcp添加指定需要开放的端口：firewall-cmd --add-port=15672/tcp --permanent重载入添加的端口：firewall-cmd --reload查询指定端口是否开启成功：firewall-cmd --query-port=15672/tcp移除指定端口

GC-扫地僧

1685人浏览 · 2021-11-07 01:33:28

GC-扫地僧 · 2021-11-07 01:33:28 发布

01：主机无法访问虚拟机MQ

查询指定端口是否已开

firewall-cmd --query-port=15672/tcp

添加指定需要开放的端口：

firewall-cmd --add-port=15672/tcp --permanent

重载入添加的端口：

firewall-cmd --reload

查询指定端口是否开启成功：

firewall-cmd --query-port=15672/tcp

移除指定端口：

firewall-cmd --permanent --remove-port=15672/tcp

查询开放的防火墙列表

firewall-cmd --zone=public --list-ports

2：com.rabbitmq.client.ShutdownSignalException: connection error

在使用浏览器可以访问，但是用程序就访问不到了。是因为浏览器访问的端口是15672。

但是用java程序连接，端口就变成了5672。

所有需要在linux中，将5672端口开放。

开放 5672端口

firewall-cmd --add-port=5672/tcp --permanent

重载入添加的端口：

firewall-cmd --reload

03：第二次接受到发送的MQ 后，发现消费获取了两个值，队列中的两个没有删除。

原因是因为MQ默认的是手动应答机制，所以要使用 autoAck = true

下面的API 是手动应答机制

/**
     * Start a non-nolocal, non-exclusive consumer, with
     * explicit acknowledgement and a server-generated consumerTag.
     * Provide access only to <code>basic.deliver</code> and
     * <code>basic.cancel</code> AMQP methods (which is sufficient
     * for most cases). See methods with a {@link Consumer} argument
     * to have access to all the application callbacks.
     * @param queue the name of the queue
     * @param deliverCallback callback when a message is delivered
     * @param cancelCallback callback when the consumer is cancelled
     * @return the consumerTag generated by the server
     * @throws IOException if an error is encountered
     * @see com.rabbitmq.client.AMQP.Basic.Consume
     * @see com.rabbitmq.client.AMQP.Basic.ConsumeOk
     * @see #basicAck
     * @see #basicConsume(String, boolean, String, boolean, boolean, Map, Consumer)
     * @since 5.0
     */
    String basicConsume(String queue, DeliverCallback deliverCallback, CancelCallback cancelCallback) throws IOException;

应使用下面API 并将 autoAck = true

/**
     * Start a non-nolocal, non-exclusive consumer, with
     * a server-generated consumerTag.
     * Provide access only to <code>basic.deliver</code> and
     * <code>basic.cancel</code> AMQP methods (which is sufficient
     * for most cases). See methods with a {@link Consumer} argument
     * to have access to all the application callbacks.
     * @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 deliverCallback callback when a message is delivered
     * @param cancelCallback callback when the consumer is cancelled
     * @return the consumerTag generated by the server
     * @throws IOException if an error is encountered
     * @see com.rabbitmq.client.AMQP.Basic.Consume
     * @see com.rabbitmq.client.AMQP.Basic.ConsumeOk
     * @see #basicAck
     * @see #basicConsume(String, boolean, String, boolean, boolean, Map, Consumer)
     * @since 5.0
     */
    String basicConsume(String queue, boolean autoAck, DeliverCallback deliverCallback, CancelCallback cancelCallback) throws IOException;

修改代码

        /**
         * 消费者消费消息
         * 1.消费哪个队列
         * 2.消费成功之后是否要自动应答 true 代表自动应答 false 手动应答
         * 3.消费者成功消费回的调
         * 4.消费者未成功消费的回调
         */
        channel.basicConsume(RabbitMQUtils.QUEUE_NAME, true, deliverCallback, cancelCallback);

作者：Darren

QQ：603026148

以上内容归Darren所有，如果有什么错误或者不足的地方请联系我，希望我们共同进步。