生产者将信道设置成 confirm 模式，一旦信道进入 confirm 模式， 所有在该信道上面发布的

消息都将会被指派一个唯一的 ID (从 1 开始)，一旦消息被投递到所有匹配的队列之后，broker

就会发送一个确认给生产者(包含消息的唯一 ID)，这就使得生产者知道消息已经正确到达目的队

列了，如果消息和队列是可持久化的，那么确认消息会在将消息写入磁盘之后发出，broker 回传

给生产者的确认消息中 delivery-tag 域包含了确认消息的序列号，此外 broker 也可以设置

basic.ack 的 multiple 域，表示到这个序列号之前的所有消息都已经得到了处理。

单个确认发布  

import cn.hutool.core.lang.UUID;
import com.rabbitmq.client.Channel;public class publishMessageIndividually {private static final int MESSAGE_COUNT = 5;public static void publishMessageIndividually() throws Exception {try (Channel channel = RabbitMqUtils.getChannel()) {String queueName = UUID.randomUUID().toString();channel.queueDeclare(queueName, false, false, false, null);//开启发布确认channel.confirmSelect();long begin = System.currentTimeMillis();for (int i = 0; i < MESSAGE_COUNT; i++) {String message = i + "";channel.basicPublish("", queueName, null, message.getBytes());//服务端返回 false 或超时时间内未返回，生产者可以消息重发boolean flag = channel.waitForConfirms();if (flag) {System.out.println("消息发送成功");}}long end = System.currentTimeMillis();System.out.println("发布" + MESSAGE_COUNT + "个单独确认消息,耗时" + (end - begin) +"ms");}}
}

耗时

 批量确认发布

import cn.hutool.core.lang.UUID;
import com.rabbitmq.client.Channel;public class publishMessageBatch {private static final int MESSAGE_COUNT = 5;public static void publishMessageBatch() throws Exception {try (Channel channel = RabbitMqUtils.getChannel()) {String queueName = UUID.randomUUID().toString();channel.queueDeclare(queueName, false, false, false, null);//开启发布确认channel.confirmSelect();//批量确认消息大小int batchSize = 100;//未确认消息个数int outstandingMessageCount = 0;long begin = System.currentTimeMillis();for (int i = 0; i < MESSAGE_COUNT; i++) {String message = i + "";channel.basicPublish("", queueName, null, message.getBytes());outstandingMessageCount++;if (outstandingMessageCount == batchSize) {channel.waitForConfirms();outstandingMessageCount = 0;}}//为了确保还有剩余没有确认消息 再次确认if (outstandingMessageCount > 0) {channel.waitForConfirms();}long end = System.currentTimeMillis();System.out.println("发布" + MESSAGE_COUNT + "个批量确认消息,耗时" + (end - begin) +"ms");}}public static void main(String[] args) throws Exception {publishMessageBatch.publishMessageBatch();}
}

 耗时

 异步确认发布

import cn.hutool.core.lang.UUID;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.ConfirmCallback;import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;public class publishMessageAsync {private static final int MESSAGE_COUNT = 5;public static void publishMessageAsync() throws Exception {try (Channel channel = RabbitMqUtils.getChannel()) {String queueName = UUID.randomUUID().toString();channel.queueDeclare(queueName, false, false, false, null);//开启发布确认channel.confirmSelect();/*** 线程安全有序的一个哈希表，适用于高并发的情况* 1.轻松的将序号与消息进行关联* 2.轻松批量删除条目 只要给到序列号* 3.支持并发访问*/ConcurrentSkipListMap<Long, String> outstandingConfirms = newConcurrentSkipListMap<>();/*** 确认收到消息的一个回调* 1.消息序列号* 2.true 可以确认小于等于当前序列号的消息* false 确认当前序列号消息*/ConfirmCallback ackCallback = (sequenceNumber, multiple) -> {if (multiple) {//返回的是小于等于当前序列号的未确认消息集合 是一个 mapConcurrentNavigableMap<Long, String> confirmed =outstandingConfirms.headMap(sequenceNumber, true);//清除该部分未确认消息集合confirmed.clear();}else{//只清除当前序列号的消息outstandingConfirms.remove(sequenceNumber);}};ConfirmCallback nackCallback = (sequenceNumber, multiple) -> {String message = outstandingConfirms.get(sequenceNumber);System.out.println("发布的消息"+message+"未被确认，序列号"+sequenceNumber);};/*** 添加一个异步确认的监听器* 1.确认收到消息的回调* 2.未收到消息的回调*/channel.addConfirmListener(ackCallback, nackCallback);long begin = System.currentTimeMillis();for (int i = 0; i < MESSAGE_COUNT; i++) {String message = "消息" + i;/*** channel.getNextPublishSeqNo()获取下一个消息的序列号* 通过序列号与消息体进行一个关联* 全部都是未确认的消息体*/outstandingConfirms.put(channel.getNextPublishSeqNo(), message);channel.basicPublish("", queueName, null, message.getBytes());}long end = System.currentTimeMillis();System.out.println("发布" + MESSAGE_COUNT + "个异步确认消息,耗时" + (end - begin) +"ms");}}public static void main(String[] args) throws Exception {publishMessageAsync.publishMessageAsync();}
}

耗时

 以上 3 种发布确认速度对比

单独发布消息

批量发布消息

消息出现了问题。