rabbitmq message acknowledgment mechanism: + confirm the transaction

package com.example.demo.util;

import com.rabbitmq.client.*;

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


/**
 * rabbitmq 工具类
 *
 * @author yangxj
 * @date 2020-03-25 20:30
 */
public class RabbitMQUtils {
    /**
     * 获取rabbitMq 连接
     *
     * @return
     * @throws Exception
     */
    public static Connection getConnection() throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setVirtualHost("/");
        factory.setUsername ( "ADMIN"); 
        factory.setUsername ( "ADMIN"); 
        return factory.newConnection (); 
    } 

    / ** 
     * 1. by transaction mechanisms (disadvantages: the decreases throughput mq) 
     * / 

    public void useTx () throws Exception { 
        Connection Connection = the getConnection (); 

        Channel Channel connection.createChannel = (); 

        // declare a queue 
        channel.queueDeclare ( "Test-queue", to false, to false, to false, null); 

        String Message = "Hello MQ Rabbit! "; 

        channel.txSelect (); // open transaction 

        the try { 
            channel.basicPublish (" "," Test-Queue ", null, message.getBytes ()); // send message 
            channel.confirmSelect ();// submit
        The catch} (Exception E) { 
            channel.txRollback (); // Rollback 
        } {the finally 
            channel.close (); 
            channel.close (); 
        } 

    } 

    / ** 
     * 2. Manufacturer confirm mode (serial type) 
     * Principle : when the channel channel enters confrim mode, all messages posted in the channel will be assigned a unique ID 
     * when the message is delivered to all matching queue, Broker will send an acknowledgment to the producer (including message ID); 
     * / 
    public void producterConfirmSync () throws Exception { 
        connection connection = the getConnection (); // Get rabbitMq connected 

        Channel Channel connection.createChannel = (); 

        channel.confirmSelect (); // open mode confirm 

        String message = "hello rabbit mq! " ; 
        String message2 = "The Rabbit MQ2 the Hello!";

        channel.basicPublish("", "", MessageProperties.BASIC, message.getBytes());
        channel.basicPublish("", "", MessageProperties.BASIC, message2.getBytes());

        if (channel.waitForConfirms()) { // 支持多条发送后再确认
            System.out.println("message send success..");
        } else {
            System.out.println("message send fail..");
        }
    }

    /**
     * 3. 生产者 confirm模式（异步）
     */
    public void producterConfirmAsync() throws Exception {
        Connection connection = getConnection(); // 获取rabbitMq 连接

        Channel channel = connection.createChannel();

        channel.confirmSelect();// open confirm mode 

        // ack ids
        The SortedSet <Long> ackIds = new new TreeSet <> (); 

        // Not ACK IDS 
        the SortedSet <Long> nackIds = new new TreeSet <> (); 

        for (int I = 0; I <100; I ++) { 
            String Message = "Hello MQ Rabbit: "+ I; 
            channel.basicPublish (" "," ", null, message.getBytes ()); 
        } 


        channel.addConfirmListener (new new ConfirmListener () { 
            @Override 
            public void handleAck (Long deliveryTag, Multiple Boolean) throws IOException {// sent successfully (acknowledgment) 
                // multiple single or multiple confirmation acknowledgment (true, indicating that all previous messages have the serial number has been processed) 
                ackIds.add (deliveryTag); 
            } 

            @Override
            public void handleNack (long deliveryTag, boolean multiple) throws IOException {// transmission failed (unacknowledged) 
                nackIds.add (deliveryTag); 
            } 
        }); 
    } 

    / ** 
     * consumer Confirm 
     * / 
    public void consumerConfirm () throws Exception { 
        connection connection = getConnection (); // Get rabbitMq connected 

        Channel Channel connection.createChannel = (); 

        the try { 
            channel.basicConsume ( "Test", to false, // automatically turn off the consumer ACK 
                    new new DefaultConsumer (Channel) { 
                        @Override 
                        public void handleDelivery (String consumerTag,
                                                   Envelope Envelope, 
                                                   AMQP.BasicProperties Properties, 
                                                   byte [] body) 
                                throws IOException { 
                            // release of each message will receive a unique deliveryTag, deliveryTag channel is unique within the scope of 
                            Long deliveryTag envelope.getDeliveryTag = (); 
                            // first two parameters are the bulk acknowledgment flag. If true, the bulk acknowledgment is executed, the received message to confirm before all deliveryTag; 
                            // if the value is false, only the currently received message to confirm 
                            channel.basicAck (deliveryTag, true); // Confirm 
                        } 
                    });
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            channel.close();
            connection.close();
        }
    }



}