Java实现Kafka的生产者、消费者

川长思鸟来 2022-05-22 09:07 281阅读 0赞

## 一、生产者 ##

import org.apache.kafka.clients.producer.KafkaProducer;
    import org.apache.kafka.clients.producer.ProducerRecord;
    import java.util.Properties;
    
    public class SimpleKafkaProducer { 
        private static KafkaProducer<String, String> producer;
        private final static String TOPIC = "adienTest2";
        public SimpleKafkaProducer(){
            Properties props = new Properties();
            props.put("bootstrap.servers", "localhost:9092");
            props.put("acks", "all");
            props.put("retries", 0);
            props.put("batch.size", 16384);
            props.put("linger.ms", 1);
            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");
            //设置分区类,根据key进行数据分区
            producer = new KafkaProducer<String, String>(props);
        }
        public void produce(){
            for (int i = 30;i<40;i++){
                String key = String.valueOf(i);
                String data = "hello kafka message："+key;
                producer.send(new ProducerRecord<String, String>(TOPIC,key,data));
                System.out.println(data);
            }
            producer.close();
        }
    
        public static void main(String[] args) {
            new SimpleKafkaProducer().produce();
        }
    }

二、消费者

import org.apache.kafka.clients.consumer.ConsumerRecord;
    import org.apache.kafka.clients.consumer.ConsumerRecords;
    import org.apache.kafka.clients.consumer.KafkaConsumer;
    import org.apache.log4j.Logger;
    
    import java.util.Arrays;
    import java.util.Properties;
    
    public class SimpleKafkaConsumer {
        private static KafkaConsumer<String, String> consumer;
        private final static String TOPIC = "adienTest2"
        public SimpleKafkaConsumer(){
            Properties props = new Properties();
            props.put("bootstrap.servers", "localhost:9092");
            //每个消费者分配独立的组号
            props.put("group.id", "test2");
            //如果value合法，则自动提交偏移量
            props.put("enable.auto.commit", "true");
            //设置多久一次更新被消费消息的偏移量
            props.put("auto.commit.interval.ms", "1000");
            //设置会话响应的时间，超过这个时间kafka可以选择放弃消费或者消费下一条消息
            props.put("session.timeout.ms", "30000");
            //自动重置offset
            props.put("auto.offset.reset","earliest");
            props.put("key.deserializer",
                    "org.apache.kafka.common.serialization.StringDeserializer");
            props.put("value.deserializer",
                    "org.apache.kafka.common.serialization.StringDeserializer");
            consumer = new KafkaConsumer<String, String>(props);
        }
    
        public void consume(){
            consumer.subscribe(Arrays.asList(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",record.offset(), record.key(), record.value());
                    System.out.println();
                }
            }
        }
    
        public static void main(String[] args) {
            new SimpleKafkaConsumer().consume();
        }
    }

三、运行  
1、该生产者、消费者是运行本地搭建的kafka，所以先用命令行启动zookeeper，再启动kafka服务，还要创建本例中使用的topic：adienTest2  
2、运行生产者代码，运行结果如下：  
![这里写图片描述][70]  
3、运行消费者代码，运行结果如下：  
![这里写图片描述][70 1]

[70]: /images/20220522/27854dc7f82a46b0ba60e66451d01e20.png
[70 1]: /images/20220522/2c6bc1c862224b81a5862e3205664e31.png