消息中间件系列【java整合kafka】

1.创建一个maven工程，引入pom坐标

        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>2.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka_2.11</artifactId>
            <version>2.0.0</version>
            <exclusions>
                <exclusion>
                    <groupId>org.apache.zookeeper</groupId>
                    <artifactId>zookeeper</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

2.创建生产者

package com.fast.kafka;

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class ProducerFastStart {
    private static final String brokerList = "localhost:9092";
    private static final String topic = "ceshi";
    public static void main(String[] args) {
        Properties properties = new Properties();
        //设置key序列化器
        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        //设置重试次数
        properties.put(ProducerConfig.RETRIES_CONFIG,3);
        //设置值序列化器
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,StringSerializer.class.getName());
        //设置集群地址
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,brokerList);

        KafkaProducer<String, String> producer = new KafkaProducer<String, String>(properties);
        ProducerRecord record = new ProducerRecord<>(topic,"kafka-demo","zhangsan");
        producer.send(record);
        producer.close();
    }
}

3.创建消费者,注意标红的和生产者的不一样

package com.fast.kafka;

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 org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.kafka.common.serialization.StringSerializer;
import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

public class ConsumerFastStart {
    private static final String brokerList = "localhost:9092";
    private static final String topic = "ceshi";
    private static final String groupId = "group.demo";

    public static void main(String[] args) {
        Properties properties = new Properties();
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,StringDeserializer.class.getName());
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,brokerList);
        properties.put(ConsumerConfig.GROUP_ID_CONFIG,groupId);

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(properties);
        consumer.subscribe(Collections.singleton(topic));
        while (true){
            ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(1000));
            for (ConsumerRecord<String, String> record : records) {
                System.out.println("record = " + record);
            }
        }
    }
}