Kafka Java 牛刀小试

1、producer --生产者

package com.nanine.kafka;

import java.util.Properties;

import org.apache.kafka.clients.producer.KafkaProducer;

import org.apache.kafka.clients.producer.Producer;

import org.apache.kafka.clients.producer.ProducerRecord;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * @author WangZhanpeng

*/

public class KafkaProducerDemo {

Logger logger = LoggerFactory.getLogger(KafkaProducerDemo.class);

public static void main(String[] args) throws InterruptedException {

Properties props = new Properties();

 //A list of host/port pairs to use for establishing the initial connection to the Kafka cluster

 props.put("bootstrap.servers", "localhost:9092");

 //This mean leader will wait for the full set of in-sync replicas to acknowledge the record;

 props.put("acks", "all");

 //Setting a value greater than zero will cause the client to resend any record whose send fails with a potentially transient error

 props.put("retries", 0);

 // This configuration controls the default batch size in bytes.

 props.put("batch.size", 16384);

 //The milliseconds to delay

 props.put("linger.ms", 1);

 //This setting should correspond roughly to the total memory the producer will use, but is not a hard 

 //bound since not all memory the producer uses is used for buffering 

 props.put("buffer.memory", 33554432);

 props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");

 props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

 Producer<String, String> producer = new KafkaProducer<>(props);

 for (int i = 0; i < 100; i++){

     producer.send(new ProducerRecord<String, String>("my-topic", Integer.toString(i), Integer.toString(i)));

     Thread.sleep(1000);

 }

 producer.close();

}

}

2、消费者-consumer

package com.nanine.kafka;

import java.util.Arrays;

import java.util.Properties;

import org.apache.kafka.clients.consumer.Consumer;

import org.apache.kafka.clients.consumer.ConsumerRecord;

import org.apache.kafka.clients.consumer.ConsumerRecords;

import org.apache.kafka.clients.consumer.KafkaConsumer;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * @author WangZhanpeng

*/

public class KafkaConsumerDemo {

Logger logger = LoggerFactory.getLogger(KafkaConsumerDemo.class);

public static void main(String[] args) {

Properties props = new Properties();

    props.put("bootstrap.servers", "localhost:9092");

    //A unique string that identifies the consumer group this consumer belongs to.

    props.put("group.id", "wangzhefeng");

    //If true the consumer's offset will be periodically committed in the background.

    props.put("enable.auto.commit", "true");

    //The frequency in milliseconds that the consumer offsets are auto-committed to Kafka if enable.auto.commit is set to true.

    props.put("auto.commit.interval.ms", "1000");

    props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

    props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

    Consumer<String,String> consumer = new KafkaConsumer<>(props);

    //Pointed the topic (same to the topic of producer)

    consumer.subscribe(Arrays.asList("my-topic"));

    while (true) {

        ConsumerRecords<String, String> records = consumer.poll(100);

        for (ConsumerRecord<String, String> record : records)

            System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());

    }

}

}

3、eclipse 导出KafkaProducerDemo .jar 、KafkaConsumerDemo.jar 指定main 函数以及依赖文件lib；

4、linux 启动生产者和消费者；

     java -Djava.ext.dirs=./lib   -jar KafkaProducerDemo .jar ;

     java -Djava.ext.dirs=./lib   -jar KafkaConsumerDemo.jar ;