0.前言
白嫖的答案←戳我**
1.说明
Spring集成使用方便 Kafka消息队列 ， 只需引入依赖包spring-kafka, 注意版本兼容性， 本文详细介绍SpringBoot集成Kafka的方法， 以及如何使用生产者和消费者。
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> 建议通过具体版本号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";
@Autowired
private 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 {
@Autowired
private ProviderService providerService;
@Override
public void afterPropertiesSet() throws Exception {
Thread t = new Thread(new Runnable() {
@Override
public 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 = 1
batch.size = 16384
bootstrap.servers = [10.21.13.14:9092]
buffer.memory = 33554432
client.dns.lookup = default
client.id = producer-1
compression.type = none
connections.max.idle.ms = 540000
delivery.timeout.ms = 120000
enable.idempotence = false
interceptor.classes = []
key.serializer = class org.apache.kafka.common.serialization.StringSerializer
linger.ms = 0
max.block.ms = 60000
max.in.flight.requests.per.connection = 5
max.request.size = 1048576
metadata.max.age.ms = 300000
metadata.max.idle.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.recording.level = INFO
metrics.sample.window.ms = 30000
partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
receive.buffer.bytes = 32768
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 30000
retries = 2147483647
retry.backoff.ms = 100
sasl.client.callback.handler.class = null
sasl.jaas.config = null
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.login.callback.handler.class = null
sasl.login.class = null
sasl.login.refresh.buffer.seconds = 300
sasl.login.refresh.min.period.seconds = 60
sasl.login.refresh.window.factor = 0.8
sasl.login.refresh.window.jitter = 0.05
sasl.mechanism = GSSAPI
security.protocol = PLAINTEXT
security.providers = null
send.buffer.bytes = 131072
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2]
ssl.endpoint.identification.algorithm = https
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLSv1.2
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.location = null
ssl.truststore.password = null
ssl.truststore.type = JKS
transaction.timeout.ms = 60000
transactional.id = null
value.serializer = class org.springframework.kafka.support.serializer.JsonSerializer
2022-04-28 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 = true
auto.commit.interval.ms = 5000
auto.offset.reset = latest
bootstrap.servers = [10.21.13.14:9092]
check.crcs = true
client.dns.lookup = default
client.id =
client.rack =
connections.max.idle.ms = 540000
default.api.timeout.ms = 60000
enable.auto.commit = false
exclude.internal.topics = true
fetch.max.bytes = 52428800
fetch.max.wait.ms = 500
fetch.min.bytes = 1
group.id = testGroup
group.instance.id = null
heartbeat.interval.ms = 3000
interceptor.classes = []
internal.leave.group.on.close = true
isolation.level = read_uncommitted
key.deserializer = class org.apache.kafka.common.serialization.StringDeserializer
max.partition.fetch.bytes = 1048576
max.poll.interval.ms = 300000
max.poll.records = 500
metadata.max.age.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.recording.level = INFO
metrics.sample.window.ms = 30000
partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
receive.buffer.bytes = 65536
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 30000
retry.backoff.ms = 100
sasl.client.callback.handler.class = null
sasl.jaas.config = null
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.login.callback.handler.class = null
sasl.login.class = null
sasl.login.refresh.buffer.seconds = 300
sasl.login.refresh.min.period.seconds = 60
sasl.login.refresh.window.factor = 0.8
sasl.login.refresh.window.jitter = 0.05
sasl.mechanism = GSSAPI
security.protocol = PLAINTEXT
security.providers = null
send.buffer.bytes = 131072
session.timeout.ms = 10000
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2]
ssl.endpoint.identification.algorithm = https
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLSv1.2
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.location = null
ssl.truststore.password = null
ssl.truststore.type = JKS
value.deserializer = class org.springframework.kafka.support.serializer.JsonDeserializer
2022-04-28 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
