<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.3.10.RELEASE</version>
    <relativePath/>
</parent>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>2.3.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-amqp</artifactId>
        <version>2.3.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.rabbitmq</groupId>
        <artifactId>amqp-client</artifactId>
        <version>5.12.0</version>
    </dependency>
</dependencies>

spring:
  rabbitmq:
    host: localhost # 主機(jī)名
    port: 5672 # 端口
    username: guest # 用戶(hù)名
    password: guest # 密碼
    virtual-host: /
    template:
      receive-timeout: 2000
      reply-timeout: 2000
    listener:
      simple:
        concurrency: 1
        max-concurrency: 3
        prefetch: 1 # 消費(fèi)者每次只能預(yù)取1條數(shù)據(jù)到內(nèi)存并處理，默認(rèn)為250條
        acknowledge-mode: manual # 確定機(jī)制 manual：手動(dòng)確認(rèn)
    publisher-returns: true
    publisher-confirm-type: correlated

package com.rabbit.rpc;
import com.rabbitmq.client.*;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.TimeoutException;
/**
 * rpc服務(wù)端
 */
public class RPCServer {
    // 定義請(qǐng)求隊(duì)列常量
    private final static String REQUEST_QUEUE_NAME = "rpc_queue";
    // 定義回復(fù)隊(duì)列常量
    private final static String REPLY_QUEUE_NAME = "rpc_reply_queue";
    /**
     * 服務(wù)端啟動(dòng)入口
     */
    public static void main(String[] args) {
        // 創(chuàng)建連接
        ConnectionFactory factory = new ConnectionFactory();
        //factory.setHost("localhost");
        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            // 聲明請(qǐng)求隊(duì)列和回復(fù)隊(duì)列
            channel.queueDeclare(REQUEST_QUEUE_NAME, false, false, false, null);
            channel.queueDeclare(REPLY_QUEUE_NAME, false, false, false, null);
            // 每次僅接收一條未經(jīng)確認(rèn)的消息
            channel.basicQos(1);
            // 構(gòu)建消費(fèi)者屬性
            Consumer consumer = new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                    // 獲取消息
                    String message = new String(body, StandardCharsets.UTF_8);
                    // 進(jìn)行業(yè)務(wù)處理構(gòu)建響應(yīng)數(shù)據(jù) (這里做字符串拼接模擬響應(yīng)數(shù)據(jù))
                    String response = message + ":::";
                    // 構(gòu)造響應(yīng)基本屬性
                    AMQP.BasicProperties replyProps = new AMQP.BasicProperties.Builder()
                            .correlationId(properties.getCorrelationId())   // 設(shè)置關(guān)聯(lián)id
                            .build();
                    // 發(fā)送響應(yīng)數(shù)據(jù)到回復(fù)隊(duì)列 (rpc_reply_queue)
                    channel.basicPublish("", properties.getReplyTo(), replyProps, response.getBytes(StandardCharsets.UTF_8));
                    // 手動(dòng)回執(zhí)消息確認(rèn)消費(fèi)
                    channel.basicAck(envelope.getDeliveryTag(), false);
                }
            };
            // 消費(fèi)rpc_queue隊(duì)列的消息
            channel.basicConsume(REQUEST_QUEUE_NAME, false, consumer);
            // 持續(xù)監(jiān)聽(tīng)請(qǐng)求消息
            while (true) {
                Thread.sleep(50);
            }
        } catch (IOException | TimeoutException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

package com.rabbit.rpc;
import com.rabbitmq.client.*;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.UUID;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeoutException;
/**
 * rpc客戶(hù)端
 */
public class RPCClient {
    // 定義請(qǐng)求隊(duì)列常量
    private final static String REQUEST_QUEUE_NAME = "rpc_queue";
    // 定義回復(fù)隊(duì)列常量
    private final static String REPLY_QUEUE_NAME = "rpc_reply_queue";
    /**
     * 客戶(hù)端啟動(dòng)入口
     */
    public static void main(String[] args) {
        System.out.println("Response1: " + call("Hello, RPC Server1"));
        System.out.println("Response2: " + call("Hello, RPC Server2"));
        System.out.println("Response3: " + call("Hello, RPC Server3"));
    }
    /**
     * 發(fā)送請(qǐng)求到隊(duì)列并返回響應(yīng)數(shù)據(jù)
     *
     * @param message 請(qǐng)求消息
     * @return 響應(yīng)數(shù)據(jù)
     */
    public static String call(String message) {
        // 創(chuàng)建連接
        ConnectionFactory factory = new ConnectionFactory();
        //factory.setHost("localhost");
        String result = "";
        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            // 聲明請(qǐng)求隊(duì)列和回復(fù)隊(duì)列
            channel.queueDeclare(REQUEST_QUEUE_NAME, false, false, false, null);
            channel.queueDeclare(REPLY_QUEUE_NAME, false, false, false, null);
            // 每次僅接收一條未經(jīng)確認(rèn)的消息
            channel.basicQos(1);
            // 生成關(guān)聯(lián)id
            String correlationId = UUID.randomUUID().toString();
            // 構(gòu)造請(qǐng)求基本屬性
            AMQP.BasicProperties props = new AMQP.BasicProperties.Builder()
                    .correlationId(correlationId)   // 設(shè)置關(guān)聯(lián)id
                    .replyTo(REPLY_QUEUE_NAME)      // 設(shè)置回復(fù)隊(duì)列 (rpc_reply_queue)
                    .build();
            // 發(fā)送請(qǐng)求消息到rpc_queue隊(duì)列
            channel.basicPublish("", REQUEST_QUEUE_NAME, props, message.getBytes(StandardCharsets.UTF_8));
            // 用于保存響應(yīng)消息的阻塞隊(duì)列
            final BlockingQueue<String> response = new ArrayBlockingQueue<>(1);
            // 監(jiān)聽(tīng)回復(fù)隊(duì)列接收響應(yīng)消息
            String consumerTag = channel.basicConsume(REPLY_QUEUE_NAME, true, new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) {
                    // 通過(guò)關(guān)聯(lián)id獲取到響應(yīng)數(shù)據(jù)
                    if (properties.getCorrelationId().equals(correlationId)) {
                        response.offer(new String(body, StandardCharsets.UTF_8));
                    }
                }
            });
            // 清空阻塞隊(duì)列
            response.clear();
            // 等待接收響應(yīng)消息
            result = response.take();
            // 取消消費(fèi)者的監(jiān)聽(tīng)
            channel.basicCancel(consumerTag);
        } catch (IOException | TimeoutException | InterruptedException e) {
            e.printStackTrace();
        }
        return result;
    }
}