一、創建maven項目

二、添加依賴pom.xml
https://maven.aliyun.com/mvn/search
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>kafka_cnn</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>2.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-streams</artifactId>
<version>2.2.1</version>
</dependency>
<dependency>
<groupId> org.apache.cassandra</groupId>
<artifactId>cassandra-all</artifactId>
<version>0.8.1</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</project>
三、創建消費者類ConsumerDemo.java
package com.kafka.consumer;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import java.util.Arrays;
import java.util.Properties;
/**
* @program: kafka consumer test
* @Date: 2021/05/15 21:55
* @Author: kq
* @Description:
*/
public class ConsumerDemo {
public static void main(String[] args){
Properties properties = new Properties();
properties.put("bootstrap.servers", "192.168.1.12:9092");
/**
* consumer分組id
*/
properties.put("group.id", "zabbix_perf");
properties.put("enable.auto.commit", "true");
properties.put("auto.commit.interval.ms", "1000");
/**
* earliest
* 當各分區下有已提交的offset時,從提交的offset開始消費;無提交的offset時,從頭開始消費
* latest
* 當各分區下有已提交的offset時,從提交的offset開始消費;無提交的offset時,消費新產生的該分區下的數據
* none
* topic各分區都存在已提交的offset時,從offset后開始消費;只要有一個分區不存在已提交的offset,則拋出異常
*
*/
properties.put("auto.offset.reset", "earliest");
properties.put("session.timeout.ms", "30000");
/**
* 反序列化
* 把kafka集群二進制消息反序列化指定類型。
*/
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("my-kafka-topic5"));
while (true) {
ConsumerRecords<String, String> records = kafkaConsumer.poll(100);//100是超時時間
for (ConsumerRecord<String, String> record : records) {
System.out.printf("offset = %d, value = %s", record.offset(), record.value());
System.out.println();
}
}
}
}
四、創建生產者類ProducerDemo.java
package com.kafka.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;
/**
* @program: kafka producer test
* @Date: 2021/05/15 21:55
* @Author: kq
* @Description:
*/
public class ProducerDemo {
public static void main(String[] args){
Properties properties = new Properties();
/**
*bootstrap.server用於建立到Kafka集群的初始連接的主機/端口對的列表,如果有兩台以上的機器,逗號分隔
*/
properties.put("bootstrap.servers", "192.168.1.12:9092");
/**
* acks有三種狀態
* acks=0 不等待服務器確認直接發送消息,無法保證服務器收到消息數據
* acks=1 把消息記錄寫到本地,但不會保證所有的消息數據被確認記錄的情況下進行釋放
* acks=all 確認所有的消息數據被同步副本確認,這樣保證了記錄不會丟失
*
*/
properties.put("acks", "all");
/**
* 設置成大於0將導致客戶端重新發送任何發送失敗的記錄
*
*/
properties.put("retries", 0);
/**
*16384字節是默認設置的批處理的緩沖區
*/
properties.put("batch.size", 16384);
properties.put("linger.ms", 1);
properties.put("buffer.memory", 33554432);
/**
* 序列化類型。
* kafka是以鍵值對的形式發送到kafka集群的,其中key是可選的,value可以是任意類型,Message再被發送到kafka之前,Producer需要
* 把不同類型的消息轉化成二進制類型。
*/
properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
Producer<String, String> producer = null;
try {
producer = new KafkaProducer<String, String>(properties);
for (int i = 0; i < 5; i++) {
String msg = "{Message " + i+"[{\"partitions\": [{\"topic\": \"my-kafka-topic5\", \"partition\": 4, \"offset\": 27}], \"version\":1 },{\"partitions\": [{\"topic\": \"my-kafka-topic5\", \"partition\": 4, \"offset\": 27}], \"version\":1 },{\"partitions\": [{\"topic\": \"my-kafka-topic5\", \"partition\": 4, \"offset\": 27}], \"version\":1 }]";
producer.send(new ProducerRecord<String, String>("my-kafka-topic5", msg));
System.out.println("Sent:" + msg);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
producer.close();
}
}
}
