文章目录
- 1、指定offset消费
- 1.1、创建消费者监听器‘
- 1.2、application.yml配置
- 1.3、使用 Java代码 创建 主题 my_topic1 并建立3个分区并给每个分区建立3个副本
- 1.4、创建生产者发送消息
- 1.4.1、分区0中的数据
- 1.5、创建SpringBoot启动类
- 1.6、屏蔽 kafka debug 日志 logback.xml
- 1.7、引入spring-kafka依赖
- 1.8、消费者控制台：
1、指定offset消费
1.1、创建消费者监听器‘
package com.atguigu.spring.kafka.consumer.listener;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.kafka.annotation.PartitionOffset;
import org.springframework.kafka.annotation.TopicPartition;
import org.springframework.stereotype.Component;
@Component
public class MyKafkaPartitionListener {
//初始化偏移量指定后，每次重启都会从该位置消费一轮，所以一般是调式解决问题时才使用
@KafkaListener(
topicPartitions = {
@TopicPartition(topic = "my_topic1"
,partitionOffsets = {
@PartitionOffset(partition = "0",initialOffset = "2")
})}
, groupId = "my_group1")
public void onMessage1(ConsumerRecord<String, String> record) {
System.out.println("my_group1消费者1获取到消息：topic = "+ record.topic()
+"，partition:"+record.partition()
+"，offset = "+record.offset()
+"，key = "+record.key()
+"，value = "+record.value());
}
}
1.2、application.yml配置
server:
port: 8120
# v1
spring:
Kafka:
bootstrap-servers: 192.168.74.148:9095,192.168.74.148:9096,192.168.74.148:9097
consumer:
# read-committed读事务已提交的消息 解决脏读问题
isolation-level: read-committed # 消费者的事务隔离级别：read-uncommitted会导致脏读，可以读取生产者事务还未提交的消息
# 消费者是否自动ack ：true自动ack 消费者获取到消息后kafka提交消费者偏移量
enable-auto-commit: true
# 消费者提交ack时多长时间批量提交一次
auto-commit-interval: 1000
# 消费者第一次消费主题消息时从哪个位置开始
auto-offset-reset: earliest #指定Offset消费:earliest | latest | none
key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
1.3、使用 Java代码 创建 主题 my_topic1 并建立3个分区并给每个分区建立3个副本
package com.atguigu.spring.kafka.consumer.config;
import org.apache.kafka.clients.admin.NewTopic;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.config.TopicBuilder;
@Configuration
public class MyKafkaConfig {
@Bean
public NewTopic springTestPartitionTopic() {
return TopicBuilder.name("my_topic1") //主题名称
.partitions(3) //分区数量
.replicas(3) //副本数量
.build();
}
}
1.4、创建生产者发送消息
package com.atguigu.spring.kafka.consumer;
import jakarta.annotation.Resource;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.kafka.core.KafkaTemplate;
@SpringBootTest
class SpringKafkaConsumerApplicationTests {
@Resource
KafkaTemplate kafkaTemplate;
@Test
void contextLoads() {
for (int i = 0; i < 10; i++) {
kafkaTemplate.send("my_topic1",i%3,"", "指定分区消费"+i);
}
}
}
1.4.1、分区0中的数据
[
[
{
"partition": 0,
"offset": 0,
"msg": "指定offset消费0",
"timespan": 1717660785962,
"date": "2024-06-06 07:59:45"
},
{
"partition": 0,
"offset": 1,
"msg": "指定offset消费3",
"timespan": 1717660785974,
"date": "2024-06-06 07:59:45"
},
{
"partition": 0,
"offset": 2,
"msg": "指定offset消费6",
"timespan": 1717660785975,
"date": "2024-06-06 07:59:45"
},
{
"partition": 0,
"offset": 3,
"msg": "指定offset消费9",
"timespan": 1717660785975,
"date": "2024-06-06 07:59:45"
}
]
]
1.5、创建SpringBoot启动类
package com.atguigu.spring.kafka.consumer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
// Generated by http://start.springboot.io
// 优质的 spring/boot/data/security/cloud 框架中文文档尽在 => http://springdoc.cn
@SpringBootApplication
public class SpringKafkaConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringKafkaConsumerApplication.class, args);
}
}
1.6、屏蔽 kafka debug 日志 logback.xml
<configuration>
<logger name="org.apache.kafka.clients" level="debug" />
</configuration>
1.7、引入spring-kafka依赖
<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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.0.5</version>
<relativePath/>
</parent>
<groupId>com.atguigu</groupId>
<artifactId>spring-kafka-consumer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-kafka-consumer</name>
<description>spring-kafka-consumer</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
1.8、消费者控制台：
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v3.0.5)
my_group1消费者1获取到消息：topic = my_topic1，partition:0，offset = 2，key = ，value = 指定offset消费6
my_group1消费者1获取到消息：topic = my_topic1，partition:0，offset = 3，key = ，value = 指定offset消费9
此时如果重新启动 SpringKafkaConsumerApplication 消费者还是会消费数据，重复消费
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v3.0.5)
my_group1消费者1获取到消息：topic = my_topic1，partition:0，offset = 2，key = ，value = 指定offset消费6
my_group1消费者1获取到消息：topic = my_topic1，partition:0，offset = 3，key = ，value = 指定offset消费9
