queue与消费者

• 是否自动ack
• 手动ack时，是否确认所有消息

自动ack

/**
   * 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)
   */
     channel.basicConsume("helloWorld", true, new Reciver(channel));

手动ack

channel.basicConsume("helloWorld", false, new Reciver(channel));

 @Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
            //super.handleDelivery(consumerTag, envelope, properties, body);
            System.out.println(new String(body));
       /**
     * 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
     */
            channel.basicAck(envelope.getDeliveryTag(),false);
}