消息确认机制---confirm异步

一：介绍

1.异步模式介绍

　　Channel对象提供ConfirmListener()回调方法只包含deliverTag（当前Channel发出的序列号），我们需要自己为每一个Channel维护一个unconfirm的消息序列集合，没publish一条数据，集合就加1，每回调一次handleAck方法，unconfirm集合删掉相应的一条（multiple=false）或者多条（multiple=true）记录。从程序运行效率上看，这个unconfirm集合最好采用有序集合SortedSet存储结构。

二：程序

1.生产者

 package com.mq.AsynConfirm;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.ConfirmListener;
 import com.rabbitmq.client.Connection;

 import java.io.IOException;
 import java.util.Collections;
 import java.util.SortedSet;
 import java.util.TreeSet;

 public class Send {
     private static final String QUEUE_NAME="test_queue_confirm_asyn";
     public static void main(String[] args)throws Exception{
         Connection connection= ConnectionUtil.getConnection();
         Channel channel=connection.createChannel();
         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
         //生产者调用confirmSelect将channel设置为nconfirm模式
         channel.confirmSelect();
         final SortedSet<Long> confirmSet= Collections.synchronizedSortedSet(new TreeSet<Long>());
         channel.addConfirmListener(new ConfirmListener() {
             //没有问题
             public void handleAck(long deliveryTag, boolean multiple) throws IOException {
                 if (multiple){
                     System.out.println("handleAck multiple");
                     confirmSet.headSet(deliveryTag+1).clear();
                 }else{
                     System.out.println("handleAck false");
                     confirmSet.remove(deliveryTag);
                 }
             }
             //有问题
             public void handleNack(long deliveryTag, boolean multiple) throws IOException {
                 if (multiple){
                     System.out.println("handleNack multiple");
                     confirmSet.headSet(deliveryTag+1).clear();
                 }else{
                     System.out.println("handleNack false");
                     confirmSet.remove(deliveryTag);
                 }
             }
         });
         String msg="success";
         while (true){
             long seqNo=channel.getNextPublishSeqNo();
             channel.basicPublish("",QUEUE_NAME,null,msg.getBytes());
             confirmSet.add(seqNo);
         }

     }
 }

2.消费者

 package com.mq.AsynConfirm;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.*;

 import java.io.IOException;

 public class Receive {
     private static final String QUEUE_NAME="test_queue_confirm_asyn";
     public static void main(String[] args)throws Exception {
         Connection connection = ConnectionUtil.getConnection();
         Channel channel = connection.createChannel();
         channel.queueDeclare(QUEUE_NAME, false, false, false, null);
         channel.basicConsume(QUEUE_NAME,true,new DefaultConsumer(channel){
             @Override
             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                 System.out.println(new String(body,"utf-8"));
             }
         });
     }
 }

3.现象

　　Send：