可以换成C++嘛-Go服务器开发

当然可以！下面是一个使用C++和librdkafka库将数据发送到Kafka并消费后写入MySQL数据库的简单示例。

首先，确保你已经安装了以下组件：

Apache Kafka
MySQL数据库
librdkafka库（可在https://github.com/edenhill/librdkafka 下载）

步骤1: 创建Kafka主题

使用以下命令创建一个名为”test_topic”的Kafka主题：

bin/kafka-topics.sh --create --topic test_topic --bootstrap-server localhost:9092 --partitions 1 --replication-factor 1

步骤2: 编写生产者代码

#include <iostream>
#include <string>
#include <cstdlib>
#include <librdkafka/rdkafkacpp.h>
class ExampleDeliveryReportCb : public RdKafka::DeliveryReportCb {
public:
    void dr_cb(RdKafka::Message &message) {
        if (message.err()) {
            std::cerr << "Failed to deliver message: " << message.errstr() << std::endl;
        } else {
            std::cout << "Message delivered to topic '" << message.topic_name()
                      << "' partition " << message.partition() << std::endl;
        }
    }
};
int main() {
    std::string brokers = "localhost:9092";
    std::string topic = "test_topic";
    // 生产者配置
    RdKafka::Conf *conf = RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL);
    conf->set("metadata.broker.list", brokers, errstr);
    // 创建生产者实例
    RdKafka::Producer *producer = RdKafka::Producer::create(conf, errstr);
    if (!producer) {
        std::cerr << "Failed to create producer: " << errstr << std::endl;
        delete conf;
        return 1;
    }
    ExampleDeliveryReportCb delivery_report_cb;
    // 创建消息
    std::string message_str = "Hello, Kafka!";
    RdKafka::Message *message = RdKafka::Message::create(producer, topic,
                                                         RdKafka::Topic::PARTITION_UA,
                                                         RdKafka::ProducerImpl::RK_MSG_COPY,
                                                         const_cast<char *>(message_str.c_str()),
                                                         message_str.size(),
                                                         NULL, 0, 0);
    // 发送消息
    producer->produce(message);
    // 等待发送完成
    producer->flush(10000);
    // 清理资源
    delete message;
    delete producer;
    delete conf;
    return 0;
}

步骤3: 编写消费者代码

#include <iostream>
#include <cstdlib>
#include <string>
#include <mysql/mysql.h>
#include <librdkafka/rdkafkacpp.h>
class ExampleConsumeCb : public RdKafka::ConsumeCb {
public:
	void consume_cb(RdKafka::Message &msg, void *opaque) {
		if (msg.err() == RdKafka::ERR_NO_ERROR) {
			std::cout << "Received message: " << std::string(static_cast<char *>(msg.payload()), msg.len()) << std::endl;
			// 在这里执行将数据写入MySQL数据库的操作，示例代码如下：
			MYSQL *connection = mysql_init(NULL);
			if (!connection) {
				std:cerr << "Failed to initialize MySQL connection" << std::endl;
				return;
			}
			if (!mysql_real_connect(connection, "localhost", "your_username", "your_password", "your_database_name", 0, NULL, 0)) {
				std::cerr << "Failed to connect to MySQL database: " << mysql_error(connection) << std::endl;
				mysql_close(connection);
				return;
			}
			std::string data(static_cast<char *>(msg.payload()), msg.len());
			std::string query = "INSERT INTO your_table (data_column) VALUES ('" + data + "')";
			if (mysql_query(connection, query.c_str())) {
				std::cerr << "Failed to execute MySQL query: " << mysql_error(connection) << std::endl;
			} else {
				std::cout << "Data inserted into MySQL database" << std::endl;
			}
			mysql_close(connection);
		}
	}
};
int main() {
    std::string brokers = "localhost:9092";
    std::string group_id = "test_group";
    std::string topic = "test_topic";
    // 消费者配置
    RdKafka::Conf *conf = RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL);
    conf->set("metadata.broker.list", brokers, errstr);
    conf->set("group.id", group_id, errstr);
    // 创建消费者实例
    RdKafka::Consumer *consumer = RdKafka::Consumer::create(conf, errstr);
    if (!consumer) {
        std::cerr << "Failed to create consumer: " << errstr << std::endl;
        delete conf;
        return 1;
    }
    ExampleConsumeCb consume_cb;
    // 订阅主题
	RdKafka::ErrorCode subscribe_err =
	    consumer->subscribe({topic}, consume_cb);
	if (subscribe_err != RdKafka::ERR_NO_ERROR) {
		std::cerr << "Failed to subscribe to topic: "
		          << RdKafka::err2str(subscribe_err) << std::endl;
        delete consumer;
        delete conf;
        return 1;
	}
    // 消费消息
	while (true) {
	    RdKafka::Message *msg = consumer->consume(1000);
	    consume_cb.consume_cb(*msg, nullptr);
	    delete msg;
	}
    // 清理资源
    consumer->close();
    delete consumer;
    delete conf;
	return 0;
}