kafka—生产者API

kafka—生产者API

maven依赖

 <dependency>
      <groupId>org.apache.kafka</groupId>
      <artifactId>kafka-clients</artifactId>
      <version>${kafka.version}</version>
    </dependency>

入门案例

import com.test.demo.config.KafkaConfig;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import java.util.Properties;

/**
 * @author bigTree
*/
public class ProducersOne {
    public static final String TOPIC = "producers_one";
    private static final String PRODUCER_KEY_SER = StringSerializer.class.getName();
    private static final String PRODUCER_VALUE_SER = StringSerializer.class.getName();
    private static final String BROKER_LIST = "hdp01:9092,hdp02:9092,hdp03:9092";
    /**
    * 生产者初始化
    */
    public static Properties getInitProducer() {
        Properties properties = new Properties();
        properties.put("bootstrap.servers", BROKER_LIST);
        properties.put("key.serializer", PRODUCER_KEY_SER);
        properties.put("value.serializer", PRODUCER_VALUE_SER);
        return properties;
    }


    public static void  main(String[] args) {
        //基础配置
        Properties init = getInitProducer();
        //获取生产者
        KafkaProducer<String, People> producer = new KafkaProducer<>(init);
        //指定消息发送的相关配置
        String message = "hello, Tom ";
        ProducerRecord<String,String> record = new ProducerRecord<>(TOPIC, message);
       //发送消息
        try{
            for (int i = 0; i < 10; i++) {
                producer.send(record);
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            //释放资源
            producer.close();
        }
    }
}

消息发送三种模式

1.发后即忘（fire-and-forget）:发送消息不关注是否发送成功。性能最好，可靠性最差
2.异步（async）：send方法本身是异步的,使用Callback方式：kafka响应时回调，要么发送成功要么抛出异常

try{
    producer.send(record, new Callback() {
        //RecordMetadata和Exception是互斥的
        @Override
        public void onCompletion(RecordMetadata metadata, Exception exception) {
            if(exception != null){
                exception.printStackTrace();
            }else{
                String topic = metadata.topic();
                int partition = metadata.partition();
                System.out.println("topic:"+ topic +",partition:"+ partition);
            }
        }
    });
}catch (Exception e){
    e.printStackTrace();
}finally {
    producer.close();
}

3.同步（sync）：send返回的Future对象链式调用get(),阻塞式等待返回结果

try {
    producer.send(record).get();
    ////方式一：可设置超时时间
   //producer.send(record).get(1000L,MILLISECONDS);
    //方式二：可获取一些元数据信息
    // Future<RecordMetadata> future = producer.send(record);
    // RecordMetadata metadata = future.get();
    // String topic = metadata.topic();
    // int partition = metadata.partition();
    // System.out.println("topic:"+ topic +",partition:"+ partition);
} catch (InterruptedException e) {
    e.printStackTrace();
} catch (ExecutionException e) {
    e.printStackTrace();
}finally {
    producer.close();
}