java--kafka编程实例--producer和consumer

最新推荐文章于 2023-07-14 08:53:04 发布

后打开撒打发了

最新推荐文章于 2023-07-14 08:53:04 发布

阅读量1.5k

点赞数

分类专栏： java 云计算&分布式 kafka

本文链接：https://blog.csdn.net/chenxun_2010/article/details/72628026

版权

云计算&分布式同时被 3 个专栏收录

23 篇文章

订阅专栏

java

15 篇文章

订阅专栏

kafka

3 篇文章

订阅专栏

本文介绍了如何在Java中编写Kafka的Producer和Consumer。首先，文章提到了需要修改Kafka broker的server.properties配置文件，特别是更新listeners设置。接着，提供了Producer的代码示例，然后详细阐述了Consumer的相关实现。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

先修改broker的配置文件：

vim config/server.properties找到Socket Server Settings内容修改listeners的内容即可

producer代码如下：

import org.apache.kafka.clients.producer.Callback;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;

import java.util.Properties;
import java.util.concurrent.ExecutionException;

class KafkaProperties {
    public static final String TOPIC = "chenxun";
    public static final String KAFKA_SERVER_URL = "192.168.222.130";
    public static final int KAFKA_SERVER_PORT = 9092;
    public static final int KAFKA_PRODUCER_BUFFER_SIZE = 64 * 1024;
    public static final int CONNECTION_TIMEOUT = 100000;
    public static final String TOPIC2 = "topic2";
    public static final String TOPIC3 = "topic3";
    public static final String CLIENT_ID = "SimpleConsumerDemoClient";

    private KafkaProperties() {}
}

class Producer extends Thread {
    private final KafkaProducer<Integer, String> producer;
    private final String topic;
    private final Boolean isAsync;

    public Producer(String topic, Boolean isAsync) {
        Properties props = new Properties();
        props.put("bootstrap.servers", KafkaProperties.KAFKA_SERVER_URL + ":" + KafkaProperties.KAFKA_SERVER_PORT);
        props.put("client.id", "DemoProducer");
        props.put("key.serializer", "org.apache.kafka.common.serialization.IntegerSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        producer = new KafkaProducer<>(props);
        this.topic = topic;
        this.isAsync = isAsync;
    }

    public void run() {
        int messageNo = 1;
        while (true) {
            String messageStr = "Message_" + messageNo;
            long startTime = System.currentTimeMillis();
            if (isAsync) { // Send asynchronously
                producer.send(new ProducerRecord<>(topic,
                        messageNo,
                        messageStr), new DemoCallBack(startTime, messageNo, messageStr));
            } else { // Send synchronously
                try {
                    producer.send(new ProducerRecord<>(topic,
                            messageNo,
                            messageStr)).get();
                    System.out.println("Sent message: (" + messageNo + ", " + messageStr + ")");
                } catch (InterruptedException | ExecutionException e) {
                    e.printStackTrace();
                }
            }
            ++messageNo;
        }
    }
}

class DemoCallBack implements Callback {

    private final long startTime;
    private final int key;
    private final String message;

    public DemoCallBack(long startTime, int key, String message) {
        this.startTime = startTime;
        this.key = key;
        this.message = message;
    }

    /**
     * A callback method the user can implement to provide asynchronous handling of request completion. This method will
     * be called when the record sent to the server has been acknowledged. Exactly one of the arguments will be
     * non-null.
     *
     * @param metadata  The metadata for the record that was sent (i.e. the partition and offset). Null if an error
     *                  occurred.
     * @param exception The exception thrown during processing of this record. Null if no error occurred.
     */
    public void onCompletion(RecordMetadata metadata, Exception exception) {
        long elapsedTime = System.currentTimeMillis() - startTime;
        if (metadata != null) {
            System.out.println(
                    "message(" + key + ", " + message + ") sent to partition(" + metadata.partition() +
                            "), " +
                            "offset(" + metadata.offset() + ") in " + elapsedTime + " ms");
        } else {
            exception.printStackTrace();
        }
    }
}

public class hello {
    public static void main(String[] args) {
        boolean isAsync = args.length == 0 || !args[0].trim().equalsIgnoreCase("sync");
        boolean flag = true;
        Producer producerThread = new Producer(KafkaProperties.TOPIC, flag);
        producerThread.start();

        //Consumer consumerThread = new Consumer(KafkaProperties.TOPIC);
       // consumerThread.start();

    }
}

consumer：

import kafka.utils.ShutdownableThread;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.util.Collections;
import java.util.Properties;

class KafkaProperties {
    public static final String TOPIC = "chenxun";
    public static final String KAFKA_SERVER_URL = "192.168.222.130";
    public static final int KAFKA_SERVER_PORT = 9092;
    public static final int KAFKA_PRODUCER_BUFFER_SIZE = 64 * 1024;
    public static final int CONNECTION_TIMEOUT = 100000;
    public static final String TOPIC2 = "topic2";
    public static final String TOPIC3 = "topic3";
    public static final String CLIENT_ID = "SimpleConsumerDemoClient";

    private KafkaProperties() {}
}

public class Consumer extends ShutdownableThread {
    private final KafkaConsumer<Integer, String> consumer;
    private final String topic;

    public Consumer(String topic) {
        super("KafkaConsumerExample", false);
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KafkaProperties.KAFKA_SERVER_URL + ":" + KafkaProperties.KAFKA_SERVER_PORT);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "DemoConsumer");
        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "true");
        props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "1000");
        props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "30000");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.IntegerDeserializer");
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");

        consumer = new KafkaConsumer<>(props);
        this.topic = topic;
    }

    @Override
    public void doWork() {
        consumer.subscribe(Collections.singletonList(this.topic));
        ConsumerRecords<Integer, String> records = consumer.poll(1000);
        for (ConsumerRecord<Integer, String> record : records) {
            System.out.println("Received message: (" + record.key() + ", " + record.value() + ") at offset " + record.offset());
        }
    }

    @Override
    public String name() {
        return null;
    }

    @Override
    public boolean isInterruptible() {
        return false;
    }
}