<dependencies>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-clients</artifactId>
        <version>4.1.1</version>
    </dependency>

    <!-- OAuth SASL 인증을 위한 jose4j 라이브러리 -->
    <dependency>
        <groupId>org.bitbucket.b_c</groupId>
        <artifactId>jose4j</artifactId>
        <version>0.9.6</version>
    </dependency>

    <!-- OAuth 토큰 JSON 파싱을 위한 Jackson 라이브러리 -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.18.2</version>
    </dependency>
</dependencies>

implementation 'org.apache.kafka:kafka-clients:4.1.1'

// OAuth SASL 인증을 위한 jose4j 라이브러리
implementation 'org.bitbucket.b_c:jose4j:0.9.6'

// OAuth 토큰 JSON 파싱을 위한 Jackson 라이브러리
implementation 'com.fasterxml.jackson.core:jackson-databind:2.18.2'

package com.example.easyqueue;

import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class EasyQueueProducer {

    public static void main(String[] args) {
        // Connection configuration
        String bootstrapServers = "{BOOTSTRAP_SERVERS}";
        String tokenEndpointUrl = "{TOKEN_ENDPOINT_URL}";
        String userAccessKey = "{USER_ACCESS_KEY}";
        String secretAccessKey = "{SECRET_ACCESS_KEY}";
        String appKey = "{APP_KEY}";
        String topic = appKey + ".{TOPIC_NAME}";

        // Kafka 4.x security: Allow OAuth token endpoint URL
        System.setProperty("org.apache.kafka.sasl.oauthbearer.allowed.urls", tokenEndpointUrl);

        // Producer configuration
        Properties props = new Properties();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        props.put(ProducerConfig.CLIENT_ID_CONFIG, "java-producer");

        // SASL/OAUTHBEARER authentication configuration
        props.put("security.protocol", "SASL_SSL");
        props.put("sasl.mechanism", "OAUTHBEARER");
        props.put("sasl.login.callback.handler.class",
            "org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginCallbackHandler");
        props.put("sasl.oauthbearer.token.endpoint.url", tokenEndpointUrl);
        props.put("sasl.jaas.config",
            "org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginModule required " +
            "clientId=\"" + userAccessKey + "\" " +
            "clientSecret=\"" + secretAccessKey + "\" " +
            "scope=\"appKey:" + appKey + "\";");

        try (Producer<String, String> producer = new KafkaProducer<>(props)) {
            // Send messages
            for (int i = 0; i < 10; i++) {
                String key = "key-" + i;
                String value = "Hello EasyQueue! Message " + i;

                ProducerRecord<String, String> record = new ProducerRecord<>(topic, key, value);

                producer.send(record, (metadata, exception) -> {
                    if (exception != null) {
                        System.err.println("Failed to send message: " + exception.getMessage());
                    } else {
                        System.out.printf("Message sent successfully - Topic: %s, Partition: %d, Offset: %d%n",
                            metadata.topic(), metadata.partition(), metadata.offset());
                    }
                });
            }

            producer.flush();
            System.out.println("All messages sent successfully");
        } catch (Exception e) {
            System.err.println("Producer error: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

package com.example.easyqueue;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

public class EasyQueueConsumer {

    public static void main(String[] args) {
        // Connection configuration
        String bootstrapServers = "{BOOTSTRAP_SERVERS}";
        String tokenEndpointUrl = "{TOKEN_ENDPOINT_URL}";
        String userAccessKey = "{USER_ACCESS_KEY}";
        String secretAccessKey = "{SECRET_ACCESS_KEY}";
        String appKey = "{APP_KEY}";
        String topic = appKey + ".{TOPIC_NAME}";
        String groupId = appKey + ".{GROUP_NAME}";

        // Kafka 4.x security: Allow OAuth token endpoint URL
        System.setProperty("org.apache.kafka.sasl.oauthbearer.allowed.urls", tokenEndpointUrl);

        // Consumer configuration
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

        // SASL/OAUTHBEARER authentication configuration
        props.put("security.protocol", "SASL_SSL");
        props.put("sasl.mechanism", "OAUTHBEARER");
        props.put("sasl.login.callback.handler.class",
            "org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginCallbackHandler");
        props.put("sasl.oauthbearer.token.endpoint.url", tokenEndpointUrl);
        props.put("sasl.jaas.config",
            "org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginModule required " +
            "clientId=\"" + userAccessKey + "\" " +
            "clientSecret=\"" + secretAccessKey + "\" " +
            "scope=\"appKey:" + appKey + "\";");

        try (Consumer<String, String> consumer = new KafkaConsumer<>(props)) {
            consumer.subscribe(Collections.singletonList(topic));
            System.out.println("Started subscribing to topic: " + topic);

            while (true) {
                ConsumerRecords<String, String> records = consumer.poll(Duration.ofSeconds(10));

                for (ConsumerRecord<String, String> record : records) {
                    System.out.printf("Message received - Topic: %s, Partition: %d, Offset: %d, Key: %s, Value: %s%n",
                        record.topic(), record.partition(), record.offset(), record.key(), record.value());
                }

                consumer.commitSync();
            }
        } catch (Exception e) {
            System.err.println("Consumer error: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

pip install confluent-kafka==2.13.0

from confluent_kafka import Producer

# 접속 정보 설정
bootstrap_servers = "{BOOTSTRAP_SERVERS}"
token_endpoint_url = "{TOKEN_ENDPOINT_URL}"
user_access_key = "{USER_ACCESS_KEY}"
secret_access_key = "{SECRET_ACCESS_KEY}"
app_key = "{APP_KEY}"
topic = f"{app_key}.{{TOPIC_NAME}}"

# Producer configuration
config = {
    "bootstrap.servers": bootstrap_servers,
    "security.protocol": "SASL_SSL",
    "sasl.mechanisms": "OAUTHBEARER",
    "sasl.oauthbearer.method": "oidc",
    "sasl.oauthbearer.token.endpoint.url": token_endpoint_url,
    "sasl.oauthbearer.client.id": user_access_key,
    "sasl.oauthbearer.client.secret": secret_access_key,
    "sasl.oauthbearer.scope": f"appKey:{app_key}",
    "client.id": "py-producer"
}

def delivery_callback(err, msg):
    if err:
        print(f"Failed to send message: {err}")
    else:
        print(f"Message sent successfully - Topic: {msg.topic()}, Partition: {msg.partition()}, Offset: {msg.offset()}")

# Create producer and send messages
producer = Producer(config)

for i in range(10):
    key = f"key-{i}"
    value = f"Hello EasyQueue! Message {i}"
    producer.produce(topic, key=key, value=value, callback=delivery_callback)

producer.flush()
print("All messages sent successfully")

from confluent_kafka import Consumer

# 접속 정보 설정
bootstrap_servers = "{BOOTSTRAP_SERVERS}"
token_endpoint_url = "{TOKEN_ENDPOINT_URL}"
user_access_key = "{USER_ACCESS_KEY}"
secret_access_key = "{SECRET_ACCESS_KEY}"
app_key = "{APP_KEY}"
topic = f"{app_key}.{{TOPIC_NAME}}"
group_id = f"{app_key}.{{GROUP_NAME}}"

# Consumer configuration
config = {
    "bootstrap.servers": bootstrap_servers,
    "security.protocol": "SASL_SSL",
    "sasl.mechanisms": "OAUTHBEARER",
    "sasl.oauthbearer.method": "oidc",
    "sasl.oauthbearer.token.endpoint.url": token_endpoint_url,
    "sasl.oauthbearer.client.id": user_access_key,
    "sasl.oauthbearer.client.secret": secret_access_key,
    "sasl.oauthbearer.scope": f"appKey:{app_key}",
    "group.id": group_id,
    "auto.offset.reset": "earliest"
}

# Create consumer and receive messages
consumer = Consumer(config)
consumer.subscribe([topic])
print(f"Started subscribing to topic: {topic}")

try:
    while True:
        msg = consumer.poll(timeout=10.0)

        if msg is None:
            continue
        if msg.error():
            print(f"Consumer error: {msg.error()}")
            continue

        print(f"Message received - Topic: {msg.topic()}, Partition: {msg.partition()}, "
              f"Offset: {msg.offset()}, Key: {msg.key()}, Value: {msg.value().decode('utf-8')}")

except KeyboardInterrupt:
    print("Consumer terminated")
finally:
    consumer.close()

npm install @confluentinc/kafka-javascript@1.8.0

const { Kafka } = require("@confluentinc/kafka-javascript").KafkaJS;

const bootstrapServers = "{BOOTSTRAP_SERVERS}";
const tokenEndpointUrl = "{TOKEN_ENDPOINT_URL}";
const userAccessKey = "{USER_ACCESS_KEY}";
const secretAccessKey = "{SECRET_ACCESS_KEY}";
const appKey = "{APP_KEY}";
const topic = `${appKey}.{TOPIC_NAME}`;

const kafka = new Kafka();
const producer = kafka.producer({
  "bootstrap.servers": bootstrapServers,
  "security.protocol": "sasl_ssl",
  "sasl.mechanisms": "OAUTHBEARER",
  "sasl.oauthbearer.method": "oidc",
  "sasl.oauthbearer.token.endpoint.url": tokenEndpointUrl,
  "sasl.oauthbearer.client.id": userAccessKey,
  "sasl.oauthbearer.client.secret": secretAccessKey,
  "sasl.oauthbearer.scope": `appKey:${appKey}`,
  "client.id": "js-producer",
});

async function run() {
  try {
    console.log("Connecting producer...");
    await producer.connect();
    console.log("Producer ready");

    // Send messages
    for (let i = 0; i < 10; i++) {
      const key = `key-${i}`;
      const value = `Hello EasyQueue! Message ${i}`;

      await producer.send({
        topic: topic,
        messages: [{ key, value }],
      });
      console.log(`Sent: ${value}`);
    }

    console.log("All messages sent successfully!");

  } catch (err) {
    console.error("Producer error:", err);
  } finally {
    console.log("Disconnecting producer...");
    await producer.disconnect();
  }
}

run();

const { Kafka } = require("@confluentinc/kafka-javascript").KafkaJS;

const bootstrapServers = "{BOOTSTRAP_SERVERS}";
const tokenEndpointUrl = "{TOKEN_ENDPOINT_URL}";
const userAccessKey = "{USER_ACCESS_KEY}";
const secretAccessKey = "{SECRET_ACCESS_KEY}";
const appKey = "{APP_KEY}";
const topic = `${appKey}.{TOPIC_NAME}`;
const groupId = `${appKey}.{GROUP_NAME}`;

const kafka = new Kafka();
const consumer = kafka.consumer({
  "bootstrap.servers": bootstrapServers,
  "security.protocol": "sasl_ssl",
  "sasl.mechanisms": "OAUTHBEARER",
  "sasl.oauthbearer.method": "oidc",
  "sasl.oauthbearer.token.endpoint.url": tokenEndpointUrl,
  "sasl.oauthbearer.client.id": userAccessKey,
  "sasl.oauthbearer.client.secret": secretAccessKey,
  "sasl.oauthbearer.scope": `appKey:${appKey}`,
  "group.id": groupId,
  "auto.offset.reset": "earliest"
});

async function run() {
  try {
    console.log("Connecting consumer...");
    await consumer.connect();
    console.log("Consumer ready");

    await consumer.subscribe({ topics: [topic] });
    console.log(`Started subscribing to topic: ${topic}`);

    // Graceful shutdown
    process.on("SIGINT", async () => {
      console.log("\nDisconnecting consumer...");
      await consumer.disconnect();
      process.exit(0);
    });

    await consumer.run({
      eachMessage: async ({ topic, partition, message }) => {
        console.log(
          `Message received - Topic: ${topic}, Partition: ${partition}, ` +
          `Offset: ${message.offset}, Key: ${message.key?.toString()}, ` +
          `Value: ${message.value?.toString()}`
        );
      },
    });

  } catch (err) {
    console.error("Consumer error:", err);
    await consumer.disconnect();
  }
}

run();

module kafka-client-go

go 1.21

require github.com/confluentinc/confluent-kafka-go/v2 v2.6.1

go mod download

package main

import (
    "fmt"
    "log"

    "github.com/confluentinc/confluent-kafka-go/v2/kafka"
)

func main() {
    // 접속 정보 설정
    bootstrapServers := "{BOOTSTRAP_SERVERS}"
    tokenEndpointUrl := "{TOKEN_ENDPOINT_URL}"
    userAccessKey := "{USER_ACCESS_KEY}"
    secretAccessKey := "{SECRET_ACCESS_KEY}"
    appKey := "{APP_KEY}"
    topic := appKey + ".{TOPIC_NAME}"

    // Producer configuration
    config := kafka.ConfigMap{
        "bootstrap.servers":                   bootstrapServers,
        "security.protocol":                   "SASL_SSL",
        "sasl.mechanisms":                     "OAUTHBEARER",
        "sasl.oauthbearer.method":             "oidc",
        "sasl.oauthbearer.token.endpoint.url": tokenEndpointUrl,
        "sasl.oauthbearer.client.id":          userAccessKey,
        "sasl.oauthbearer.client.secret":      secretAccessKey,
        "sasl.oauthbearer.scope":              "appKey:" + appKey,
        "client.id": "go-producer",
    }

    producer, err := kafka.NewProducer(&config)
    if err != nil {
        log.Fatalf("Failed to create producer: %v", err)
    }
    defer producer.Close()

    // Handle delivery reports in a goroutine
    go func() {
        for e := range producer.Events() {
            switch ev := e.(type) {
            case *kafka.Message:
                if ev.TopicPartition.Error != nil {
                    fmt.Printf("Failed to send message: %v\n", ev.TopicPartition.Error)
                } else {
                    fmt.Printf("Message sent successfully - Topic: %s, Partition: %d, Offset: %d\n",
                        *ev.TopicPartition.Topic, ev.TopicPartition.Partition, ev.TopicPartition.Offset)
                }
            }
        }
    }()

    // Send messages
    for i := 0; i < 10; i++ {
        key := fmt.Sprintf("key-%d", i)
        value := fmt.Sprintf("Hello EasyQueue! Message %d", i)

        err := producer.Produce(&kafka.Message{
            TopicPartition: kafka.TopicPartition{Topic: &topic, Partition: kafka.PartitionAny},
            Key:            []byte(key),
            Value:          []byte(value),
        }, nil)

        if err != nil {
            fmt.Printf("Failed to send message request: %v\n", err)
        }
    }

    // Wait for all messages to be delivered
    producer.Flush(5000)
    fmt.Println("All messages sent successfully")
}

package main

import (
    "fmt"
    "log"
    "os"
    "os/signal"
    "syscall"

    "github.com/confluentinc/confluent-kafka-go/v2/kafka"
)

func main() {
    // 접속 정보 설정
    bootstrapServers := "{BOOTSTRAP_SERVERS}"
    tokenEndpointUrl := "{TOKEN_ENDPOINT_URL}"
    userAccessKey := "{USER_ACCESS_KEY}"
    secretAccessKey := "{SECRET_ACCESS_KEY}"
    appKey := "{APP_KEY}"
    topic := appKey + ".{TOPIC_NAME}"
    groupId := appKey + ".{GROUP_NAME}"

    // Consumer configuration
    config := kafka.ConfigMap{
        "bootstrap.servers":                   bootstrapServers,
        "security.protocol":                   "SASL_SSL",
        "sasl.mechanisms":                     "OAUTHBEARER",
        "sasl.oauthbearer.method":             "oidc",
        "sasl.oauthbearer.token.endpoint.url": tokenEndpointUrl,
        "sasl.oauthbearer.client.id":          userAccessKey,
        "sasl.oauthbearer.client.secret":      secretAccessKey,
        "sasl.oauthbearer.scope":              "appKey:" + appKey,
        "group.id":                            groupId,
        "auto.offset.reset":                   "earliest",
    }

    consumer, err := kafka.NewConsumer(&config)
    if err != nil {
        log.Fatalf("Failed to create consumer: %v", err)
    }
    defer consumer.Close()

    err = consumer.SubscribeTopics([]string{topic}, nil)
    if err != nil {
        log.Fatalf("Failed to subscribe to topic: %v", err)
    }
    fmt.Printf("Started subscribing to topic: %s\n", topic)

    // Handle termination signals
    sigchan := make(chan os.Signal, 1)
    signal.Notify(sigchan, syscall.SIGINT, syscall.SIGTERM)

    run := true
    for run {
        select {
        case sig := <-sigchan:
            fmt.Printf("Received termination signal: %v\n", sig)
            run = false
        default:
            ev := consumer.Poll(10000)
            if ev == nil {
                continue
            }

            switch e := ev.(type) {
            case *kafka.Message:
                fmt.Printf("Message received - Topic: %s, Partition: %d, Offset: %d, Key: %s, Value: %s\n",
                    *e.TopicPartition.Topic, e.TopicPartition.Partition, e.TopicPartition.Offset,
                    string(e.Key), string(e.Value))
            case kafka.Error:
                fmt.Printf("Consumer error: %v\n", e)
                if e.Code() == kafka.ErrAllBrokersDown {
                    run = false
                }
            }
        }
    }

    fmt.Println("Consumer terminated")
}