0.前言

本人整理收藏了22年多家公司面试知识点整理 ，以及各种Java核心知识点免费分享给大家，我认为对面试与学习来说是非常有用的，想要资料的话请点白嫖这份答案←戳我**

1.说明

Spring可以方便的集成使用 Kafka消息队列 ，
只需要引入依赖包spring-kafka,
注意版本兼容问题，
本文详细介绍SpringBoot集成Kafka的方法，
以及生产者和消费者的使用方法。

2.引入依赖

在 pom.xml 中引入Spring Kafka版本：

<dependency><groupId>org.springframework.kafka</groupId><artifactId>spring-kafka</artifactId>
</dependency>

具体的版本号建议通过spring-boot-dependencies管理：

<properties><spring-boot.version>2.3.1.RELEASE</spring-boot.version>
</properties>
<dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>${spring-boot.version}</version><type>pom</type><scope>import</scope></dependency></dependencies>
</dependencyManagement>

3.配置

新建applicaion.yml,
新增如下配置：

Spring Kafka 通用配置

spring:kafka:# kafka连接接地址bootstrap-servers: localhost:9092

通用配置：spring.kafka.*
下面的admin、producer、consumer、streams配置，
会覆盖通用配置 spring.kafka.* 中相同的属性。

生产者配置

spring:kafka:# 生产者配置producer:# 序列化key的类key-serializer: org.apache.kafka.common.serialization.StringSerializer # 反序列化value的类value-serializer: org.springframework.kafka.support.serializer.JsonSerializer

生产者相关配置：spring.kafka.producer.*

消费者配置

spring:kafka:# 消费者配置consumer:# 消费者所属消息组group-id: testGroup # 反序列化key的类key-deserializer: org.apache.kafka.common.serialization.StringDeserializer # 反序列化value的类value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer

消费者相关配置：spring.kafka.consumer.*

默认 value-deserializer 使用 org.apache.kafka.common.serialization.StringDeserializer ，
只支持文本消息。
使用org.springframework.kafka.support.serializer.JsonDeserializer可以让消息支持JSON。

完整applicaion.yml配置：

server:port: 8028 spring:kafka:# kafka连接接地址bootstrap-servers: localhost:9092# 生产者配置producer:# 序列化key的类key-serializer: org.apache.kafka.common.serialization.StringSerializer # 反序列化value的类value-serializer: org.springframework.kafka.support.serializer.JsonSerializer # 消费者配置consumer:# 消费者所属消息组group-id: testGroup # 反序列化key的类key-deserializer: org.apache.kafka.common.serialization.StringDeserializer # 反序列化value的类value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer

4.开发代码

新建KafkaMQApplication.java启动类，
注意要新增 @EnableKafka 注解:

package com.yuwen.spring.kafka;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.kafka.annotation.EnableKafka;@SpringBootApplication
@EnableKafka
public class KafkaMQApplication {public static void main(String[] args) {SpringApplication.run(KafkaMQApplication.class, args);}
}

生产者发送消息

Spring Kafka 提供KafkaTemplate类发送消息，
在需要的地方注入即可，
新增ProviderService.java生产者服务类：

package com.yuwen.spring.kafka.provider;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Service;@Service
public class ProviderService {public static final String TOPIC = "testTopic";@Autowiredprivate KafkaTemplate<?, String> kafkaTemplate;public void send(String message) {// 发送消息kafkaTemplate.send(TOPIC, message);System.out.println("Provider= " + message);}
}

注意指定 topic ，
以及要发送的消息内容message。

消费者接收消息

新增ConsumerService.java类，
注意使用 @KafkaListener 注解：

package com.yuwen.spring.kafka.consumer;import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Service;import com.yuwen.spring.kafka.provider.ProviderService;@Service
public class ConsumerService {@KafkaListener(topics = ProviderService.TOPIC, groupId = "testGroup", topicPartitions = {})public void receive(String message) {System.out.println("Consumer= " + message);}
}

参数说明：
topics 与发送消息topic相同，可以指定多个
groupId 消费组唯一id
topicPartitions topic分区，可指定多个

5.自动产生消息

为了测试生产者产生消息，
编写AutoGenerate.java，
自动生成随机字符串，
作为生产者向kafka发送消息：

package com.yuwen.spring.kafka.provider;import java.util.UUID;
import java.util.concurrent.TimeUnit;import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;@Component
public class AutoGenerate implements InitializingBean {@Autowiredprivate ProviderService providerService;@Overridepublic void afterPropertiesSet() throws Exception {Thread t = new Thread(new Runnable() {@Overridepublic void run() {while (true) {String message = UUID.randomUUID().toString();providerService.send(message);try {TimeUnit.SECONDS.sleep(1);} catch (InterruptedException e) {e.printStackTrace();}}}});t.start();}
}

6.运行服务

运行KafkaMQApplication.java启动类，
输出如下日志,
可以看到生产者产生的随机字符串，
能够被消费者正确获取到：

.   ____          _            __ _ _/\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \\\/  ___)| |_)| | | | | || (_| |  ) ) ) )'  |____| .__|_| |_|_| |_\__, | / / / /=========|_|==============|___/=/_/_/_/:: Spring Boot ::        (v2.3.1.RELEASE)2022-04-28 19:37:49.687  INFO 14424 --- [           main] c.yuwen.spring.kafka.KafkaMQApplication  : Starting KafkaMQApplication on yuwen-asiainfo with PID 14424 (D:\Code\Learn\SpringBoot\spring-boot-demo\MessageQueue\kafka\target\classes started by yuwen in D:\Code\Learn\SpringBoot\spring-boot-demo\MessageQueue\kafka)
2022-04-28 19:37:49.689  INFO 14424 --- [           main] c.yuwen.spring.kafka.KafkaMQApplication  : No active profile set, falling back to default profiles: default
2022-04-28 19:37:51.282  INFO 14424 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8028 (http)
2022-04-28 19:37:51.290  INFO 14424 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-04-28 19:37:51.291  INFO 14424 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.36]
2022-04-28 19:37:51.371  INFO 14424 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-04-28 19:37:51.371  INFO 14424 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1645 ms
2022-04-28 19:37:51.491  INFO 14424 --- [     Thread-119] o.a.k.clients.producer.ProducerConfig    : ProducerConfig values: acks = 1batch.size = 16384bootstrap.servers = [10.21.13.14:9092]buffer.memory = 33554432client.dns.lookup = defaultclient.id = producer-1compression.type = noneconnections.max.idle.ms = 540000delivery.timeout.ms = 120000enable.idempotence = falseinterceptor.classes = []key.serializer = class org.apache.kafka.common.serialization.StringSerializerlinger.ms = 0max.block.ms = 60000max.in.flight.requests.per.connection = 5max.request.size = 1048576metadata.max.age.ms = 300000metadata.max.idle.ms = 300000metric.reporters = []metrics.num.samples = 2metrics.recording.level = INFOmetrics.sample.window.ms = 30000partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitionerreceive.buffer.bytes = 32768reconnect.backoff.max.ms = 1000reconnect.backoff.ms = 50request.timeout.ms = 30000retries = 2147483647retry.backoff.ms = 100sasl.client.callback.handler.class = nullsasl.jaas.config = nullsasl.kerberos.kinit.cmd = /usr/bin/kinitsasl.kerberos.min.time.before.relogin = 60000sasl.kerberos.service.name = nullsasl.kerberos.ticket.renew.jitter = 0.05sasl.kerberos.ticket.renew.window.factor = 0.8sasl.login.callback.handler.class = nullsasl.login.class = nullsasl.login.refresh.buffer.seconds = 300sasl.login.refresh.min.period.seconds = 60sasl.login.refresh.window.factor = 0.8sasl.login.refresh.window.jitter = 0.05sasl.mechanism = GSSAPIsecurity.protocol = PLAINTEXTsecurity.providers = nullsend.buffer.bytes = 131072ssl.cipher.suites = nullssl.enabled.protocols = [TLSv1.2]ssl.endpoint.identification.algorithm = httpsssl.key.password = nullssl.keymanager.algorithm = SunX509ssl.keystore.location = nullssl.keystore.password = nullssl.keystore.type = JKSssl.protocol = TLSv1.2ssl.provider = nullssl.secure.random.implementation = nullssl.trustmanager.algorithm = PKIXssl.truststore.location = nullssl.truststore.password = nullssl.truststore.type = JKStransaction.timeout.ms = 60000transactional.id = nullvalue.serializer = class org.springframework.kafka.support.serializer.JsonSerializer2022-04-28 19:37:51.563  INFO 14424 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2022-04-28 19:37:51.590  INFO 14424 --- [     Thread-119] o.a.kafka.common.utils.AppInfoParser     : Kafka version: 2.5.0
2022-04-28 19:37:51.592  INFO 14424 --- [     Thread-119] o.a.kafka.common.utils.AppInfoParser     : Kafka commitId: 66563e712b0b9f84
2022-04-28 19:37:51.592  INFO 14424 --- [     Thread-119] o.a.kafka.common.utils.AppInfoParser     : Kafka startTimeMs: 1651145871589
2022-04-28 19:37:51.851  INFO 14424 --- [           main] o.a.k.clients.consumer.ConsumerConfig    : ConsumerConfig values: allow.auto.create.topics = trueauto.commit.interval.ms = 5000auto.offset.reset = latestbootstrap.servers = [10.21.13.14:9092]check.crcs = trueclient.dns.lookup = defaultclient.id = client.rack = connections.max.idle.ms = 540000default.api.timeout.ms = 60000enable.auto.commit = falseexclude.internal.topics = truefetch.max.bytes = 52428800fetch.max.wait.ms = 500fetch.min.bytes = 1group.id = testGroupgroup.instance.id = nullheartbeat.interval.ms = 3000interceptor.classes = []internal.leave.group.on.close = trueisolation.level = read_uncommittedkey.deserializer = class org.apache.kafka.common.serialization.StringDeserializermax.partition.fetch.bytes = 1048576max.poll.interval.ms = 300000max.poll.records = 500metadata.max.age.ms = 300000metric.reporters = []metrics.num.samples = 2metrics.recording.level = INFOmetrics.sample.window.ms = 30000partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]receive.buffer.bytes = 65536reconnect.backoff.max.ms = 1000reconnect.backoff.ms = 50request.timeout.ms = 30000retry.backoff.ms = 100sasl.client.callback.handler.class = nullsasl.jaas.config = nullsasl.kerberos.kinit.cmd = /usr/bin/kinitsasl.kerberos.min.time.before.relogin = 60000sasl.kerberos.service.name = nullsasl.kerberos.ticket.renew.jitter = 0.05sasl.kerberos.ticket.renew.window.factor = 0.8sasl.login.callback.handler.class = nullsasl.login.class = nullsasl.login.refresh.buffer.seconds = 300sasl.login.refresh.min.period.seconds = 60sasl.login.refresh.window.factor = 0.8sasl.login.refresh.window.jitter = 0.05sasl.mechanism = GSSAPIsecurity.protocol = PLAINTEXTsecurity.providers = nullsend.buffer.bytes = 131072session.timeout.ms = 10000ssl.cipher.suites = nullssl.enabled.protocols = [TLSv1.2]ssl.endpoint.identification.algorithm = httpsssl.key.password = nullssl.keymanager.algorithm = SunX509ssl.keystore.location = nullssl.keystore.password = nullssl.keystore.type = JKSssl.protocol = TLSv1.2ssl.provider = nullssl.secure.random.implementation = nullssl.trustmanager.algorithm = PKIXssl.truststore.location = nullssl.truststore.password = nullssl.truststore.type = JKSvalue.deserializer = class org.springframework.kafka.support.serializer.JsonDeserializer2022-04-28 19:37:51.888  INFO 14424 --- [           main] o.a.kafka.common.utils.AppInfoParser     : Kafka version: 2.5.0
2022-04-28 19:37:51.888  INFO 14424 --- [           main] o.a.kafka.common.utils.AppInfoParser     : Kafka commitId: 66563e712b0b9f84
2022-04-28 19:37:51.888  INFO 14424 --- [           main] o.a.kafka.common.utils.AppInfoParser     : Kafka startTimeMs: 1651145871888
2022-04-28 19:37:51.890  INFO 14424 --- [           main] o.a.k.clients.consumer.KafkaConsumer     : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Subscribed to topic(s): testTopic
2022-04-28 19:37:51.892  INFO 14424 --- [           main] o.s.s.c.ThreadPoolTaskScheduler          : Initializing ExecutorService
2022-04-28 19:37:51.911  INFO 14424 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8028 (http) with context path ''
2022-04-28 19:37:51.921  INFO 14424 --- [           main] c.yuwen.spring.kafka.KafkaMQApplication  : Started KafkaMQApplication in 2.582 seconds (JVM running for 2.957)
2022-04-28 19:37:51.939  INFO 14424 --- [ntainer#0-0-C-1] org.apache.kafka.clients.Metadata        : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Cluster ID: zdSPCGGvT8qBnM4LSjz9Hw
2022-04-28 19:37:51.939  INFO 14424 --- [ad | producer-1] org.apache.kafka.clients.Metadata        : [Producer clientId=producer-1] Cluster ID: zdSPCGGvT8qBnM4LSjz9Hw
2022-04-28 19:37:51.940  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.AbstractCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Discovered group coordinator 10.21.13.14:9092 (id: 2147483647 rack: null)
2022-04-28 19:37:51.942  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.AbstractCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] (Re-)joining group
2022-04-28 19:37:51.959  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.ConsumerCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Finished assignment for group at generation 5: {consumer-testGroup-1-35e34543-5bf3-4a4a-a590-9a4c6f7e1ae3=Assignment(partitions=[testTopic-0])}
Provider= c30a2e6c-e2e8-419e-865c-04885d1a90b5
2022-04-28 19:37:51.966  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.AbstractCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Successfully joined group with generation 5
2022-04-28 19:37:51.970  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.ConsumerCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Adding newly assigned partitions: testTopic-0
2022-04-28 19:37:51.984  INFO 14424 --- [ntainer#0-0-C-1] o.a.k.c.c.internals.ConsumerCoordinator  : [Consumer clientId=consumer-testGroup-1, groupId=testGroup] Setting offset for partition testTopic-0 to the committed offset FetchPosition{offset=310751, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=Optional[10.21.13.14:9092 (id: 0 rack: null)], epoch=absent}}
2022-04-28 19:37:51.985  INFO 14424 --- [ntainer#0-0-C-1] o.s.k.l.KafkaMessageListenerContainer    : testGroup: partitions assigned: [testTopic-0]
Consumer= 19210493-d0df-4cd9-993b-f99500523eb2
Consumer= baee3749-307f-4894-ad88-a9610700ab80
Consumer= bea5e807-b003-4c90-89be-20439e2fa921
Consumer= 98258208-8a95-495d-917e-84d30d965e2b
Consumer= 4301851e-ab19-4c9e-89d6-7b604acdf077
Consumer= c30a2e6c-e2e8-419e-865c-04885d1a90b5
Provider= a6d47e9e-de74-481f-82f8-02bd7384fdd8
Consumer= a6d47e9e-de74-481f-82f8-02bd7384fdd8
Provider= bd935ef1-cc61-4014-a971-1ad76c5e82bf
Consumer= bd935ef1-cc61-4014-a971-1ad76c5e82bf

7.最后

下面的面试题答案都整理成文档笔记。也还整理了一些面试资料&最新2022收集的一些大厂的面试真题（都整理成文档，小部分截图），有需要的可以