同步发送API

同步发送的意思就是，一条消息发送之后，会阻塞当前线程，直至返回ack。<br />由于send方法返回的是一个Future对象，根据Futrue对象的特点，我们也可以实现同步发送的效果，只需在调用Future对象的get方发即可。

package com.producer;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;
import java.util.Properties;
import java.util.concurrent.ExecutionException;
public class CustomProducer3 {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        Properties props = new Properties();
        props.put("bootstrap.servers", "zjj101:9092");//kafka集群，broker-list
        props.put("acks", "all");
        props.put("retries", 1);//重试次数
        props.put("batch.size", 16384);//批次大小
        props.put("linger.ms", 1);//等待时间
        props.put("buffer.memory", 33554432);//RecordAccumulator缓冲区大小
        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++) {
            //调用了get方法,就相当于同步了,这样就是发送一条等一条的结果,就是同步了
            RecordMetadata first = producer.send(new ProducerRecord<String, String>("first",
                    Integer.toString(i), Integer.toString(i))).get();
            System.out.println(first);
        }
        producer.close();
    }
}