java實現kafka訊息傳送和接收
阿新 • • 發佈:2019-01-05
之前寫了一篇關於kafka叢集搭建的點選開啟連結。想了解的可以看下。
今天這個實現是和前面叢集對應的。使用的是新版的API。屬性如果想定製自己的,需要到官方網址上面去檢視一下對應的值。
推介大家多去看看官方的介紹和demo。網上有些翻譯過來的例子並不完善,最好是知己知彼,才能百戰不殆
maven:
<dependency> <groupId>org.apache.kafka</groupId> <artifactId>kafka-clients</artifactId> <version>0.11.0.0</version> </dependency> <dependency> <groupId>org.apache.kafka</groupId> <artifactId>kafka-streams</artifactId> <version>0.11.0.0</version> </dependency>
生產者Producer:
package com.roncoo.example.kafka; import java.util.Properties; import org.apache.kafka.clients.producer.KafkaProducer; import org.apache.kafka.clients.producer.ProducerRecord; public class ProducerDemo { private final KafkaProducer<String, String> producer; public final static String TOPIC = "test5"; private ProducerDemo() { Properties props = new Properties(); props.put("bootstrap.servers", "xxx:9092,1xxx:9092,xxx:9092");//xxx伺服器ip props.put("acks", "all");//所有follower都響應了才認為訊息提交成功,即"committed" props.put("retries", 0);//retries = MAX 無限重試,直到你意識到出現了問題:) props.put("batch.size", 16384);//producer將試圖批處理訊息記錄,以減少請求次數.預設的批量處理訊息位元組數 //batch.size當批量的資料大小達到設定值後,就會立即傳送,不顧下面的linger.ms props.put("linger.ms", 1);//延遲1ms傳送,這項設定將通過增加小的延遲來完成--即,不是立即傳送一條記錄,producer將會等待給定的延遲時間以允許其他訊息記錄傳送,這些訊息記錄可以批量處理 props.put("buffer.memory", 33554432);//producer可以用來快取資料的記憶體大小。 props.put("key.serializer", "org.apache.kafka.common.serialization.IntegerSerializer"); props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer"); producer = new KafkaProducer<String, String>(props); } public void produce() { int messageNo = 1; final int COUNT = 5; while(messageNo < COUNT) { String key = String.valueOf(messageNo); String data = String.format("hello KafkaProducer message %s from hubo 06291018 ", key); try { producer.send(new ProducerRecord<String, String>(TOPIC, data)); } catch (Exception e) { e.printStackTrace(); } messageNo++; } producer.close(); } public static void main(String[] args) { new ProducerDemo().produce(); } }
消費者Consumer:
package com.roncoo.example.kafka; import java.util.Arrays; import java.util.Properties; import org.apache.kafka.clients.consumer.ConsumerRecord; import org.apache.kafka.clients.consumer.ConsumerRecords; import org.apache.kafka.clients.consumer.KafkaConsumer; public class UserKafkaConsumer extends Thread { public static void main(String[] args){ Properties properties = new Properties(); properties.put("bootstrap.servers", "xxx:9092,xxx:9092,xxx:9092");//xxx是伺服器叢集的ip properties.put("group.id", "jd-group"); properties.put("enable.auto.commit", "true"); properties.put("auto.commit.interval.ms", "1000"); properties.put("auto.offset.reset", "latest"); properties.put("session.timeout.ms", "30000"); properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer"); properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer"); KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties); kafkaConsumer.subscribe(Arrays.asList("test5")); while (true) { ConsumerRecords<String, String> records = kafkaConsumer.poll(100); for (ConsumerRecord<String, String> record : records) { System.out.println("-----------------"); System.out.printf("offset = %d, value = %s", record.offset(), record.value()); System.out.println(); } } } }