c++ kafka环境配置
本文主要介绍C++ Qt Ubuntu环境下卡夫卡的环境配置和基本收发，整理自@草上爬大神。原贴：https://blog.csdn.net/caoshangpa/article/details/79786100
非常感谢原作者。
kafka依赖安装
卡夫卡需要java才能运行，可安装openjdk11
sudo apt install openjdk-11-jdk
检查版本
java -version
kafka安装和试运行
首先下载kafkahttp://kafka.apache.org/downloads，选择scala那个。
解压即可。
卡夫卡的完整链路需要zookeeper，kafka服务，生产者，消费者四个模块。
进入解压好的目录，打开终端，输入以下指令。
开启zookeeper：
bin/zookeeper-server-start.sh config/zookeeper.properties
开启kafka服务：
bin/kafka-server-start.sh config/server.properties
kafka是订阅发布制的通信系统，所以需要topic来进行管理。创建一个名为test的topic：
bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic test
查看topic
bin/kafka-topics.sh --list --zookeeper localhost:2181
创建producer:
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test
创建consumer:
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test --from-beginning
接下来，在producer终端输入信息，consumer就可以收到啦。
librdkafka安装
首先克隆librdkafka项目：
git clone https://github.com/edenhill/librdkafka.git
接下来安装：
cd librdkafka/
./configure
make
sudo make install
-lrdkafka++
librdkafka试运行
新建一个QT工程，在.pro文件引入librdkafka：
INCLUDEPATH += /usr/local/include/librdkafka
LIBS += -L/usr/local/lib -lrdkafka
LIBS += -L/usr/local/lib -lrdkafka++
生产者源文件如下：
#include 消费者工程文件同上，源文件如下：
#include
break;
case RdKafka::ERR_NO_ERROR:
/* Real message */
msg_cnt++;
msg_bytes += message->len();
if (verbosity >= 3)
std::cerr << "Read msg at offset " << message->offset() << std::endl;
RdKafka::MessageTimestamp ts;
ts = message->timestamp();
if (verbosity >= 2 &&
ts.type != RdKafka::MessageTimestamp::MSG_TIMESTAMP_NOT_AVAILABLE) {
std::string tsname = "?";
if (ts.type == RdKafka::MessageTimestamp::MSG_TIMESTAMP_CREATE_TIME)
tsname = "create time";
else if (ts.type == RdKafka::MessageTimestamp::MSG_TIMESTAMP_LOG_APPEND_TIME)
tsname = "log append time";
std::cout << "Timestamp: " << tsname << " " << ts.timestamp << std::endl;
}
if (verbosity >= 2 && message->key()) {
std::cout << "Key: " << *message->key() << std::endl;
}
if (verbosity >= 1) {
printf("%.*s\n",
static_cast<int>(message->len()),
static_cast<const char *>(message->payload()));
}
break;
case RdKafka::ERR__PARTITION_EOF:
/* Last message */
if (exit_eof && ++eof_cnt == partition_cnt) {
std::cerr << "%% EOF reached for all " << partition_cnt <<
" partition(s)" << std::endl;
run = false;
}
break;
case RdKafka::ERR__UNKNOWN_TOPIC:
case RdKafka::ERR__UNKNOWN_PARTITION:
std::cerr << "Consume failed: " << message->errstr() << std::endl;
run = false;
break;
default:
/* Errors */
std::cerr << "Consume failed: " << message->errstr() << std::endl;
run = false;
}
}
class ExampleConsumeCb : public RdKafka::ConsumeCb {
public:
void consume_cb (RdKafka::Message &msg, void *opaque) {
msg_consume(&msg, opaque);
}
};
int main () {
std::string brokers = "localhost";
std::string errstr;
std::string topic_str="test";
std::vector<std::string> topics;
std::string group_id="101";
RdKafka::Conf *conf = RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL);
RdKafka::Conf *tconf = RdKafka::Conf::create(RdKafka::Conf::CONF_TOPIC);
//group.id必须设置
if (conf->set("group.id", group_id, errstr) != RdKafka::Conf::CONF_OK) {
std::cerr << errstr << std::endl;
exit(1);
}
topics.push_back(topic_str);
//bootstrap.servers可以替换为metadata.broker.list
conf->set("bootstrap.servers", brokers, errstr);
ExampleConsumeCb ex_consume_cb;
conf->set("consume_cb", &ex_consume_cb, errstr);
ExampleEventCb ex_event_cb;
conf->set("event_cb", &ex_event_cb, errstr);
conf->set("default_topic_conf", tconf, errstr);
signal(SIGINT, sigterm);
signal(SIGTERM, sigterm);
RdKafka::KafkaConsumer *consumer = RdKafka::KafkaConsumer::create(conf, errstr);
if (!consumer) {
std::cerr << "Failed to create consumer: " << errstr << std::endl;
exit(1);
}
std::cout << "% Created consumer " << consumer->name() << std::endl;
RdKafka::ErrorCode err = consumer->subscribe(topics);
if (err) {
std::cerr << "Failed to subscribe to " << topics.size() << " topics: "
<< RdKafka::err2str(err) << std::endl;
exit(1);
}
while (run) {
//5000毫秒未订阅到消息，触发RdKafka::ERR__TIMED_OUT
RdKafka::Message *msg = consumer->consume(5000);
msg_consume(msg, NULL);
delete msg;
}
consumer->close();
delete conf;
delete tconf;
delete consumer;
std::cerr << "% Consumed " << msg_cnt << " messages ("
<< msg_bytes << " bytes)" << std::endl;
//应用退出之前等待rdkafka清理资源
RdKafka::wait_destroyed(5000);
return 0;
}
运行zookeeper和kafka服务，再编译运行这两个文件，即可实现qq一样的收发功能。