kafka集群安装Raft 协议

使用消息中间件，可以实现系统与系统之间的异步通信和无缝对接，也可用在模块之间的的异步通信，有效避免了同步阻塞IO。作为一个高吞吐量、可扩展、高可靠性的分布式消息系统，Kafka 能够胜任从简单的消息队列到复杂的流处理平台的多种角色。MQTT消息系统和kafka是当前最常用的消息中间件。

Kafka集群组件

Broker：
- Kafka 集群中的一个服务器实例，每个 Broker 负责存储一定数量的分区。
- Broker 通过 Broker ID 进行标识。
Topic：
- 消息的逻辑分类，可以理解为消息的类别。
- 每个 Topic 可以有多个分区（Partition）。
Partition：
- 一个 Topic 被分割成多个分区，每个分区是一个有序的消息序列。
- 分区是 Kafka 中的基本并行单元，分布在不同的 Broker 上。
Producer：
- 负责向 Kafka 主题发布消息的客户端应用程序。
Consumer：
- 负责从 Kafka 主题消费消息的客户端应用程序。
Consumer Group：
- 一组消费者共同消费一个或多个主题的分区，每个分区只能被 Consumer Group 中的一个消费者消费。

分区和副本机制

Leader 和 Follower：
- 每个分区都有一个 Leader 和若干个 Follower。
- Leader 处理所有的读写请求，Follower 复制 Leader 的数据。
- 当 Leader 失效时，一个 Follower 会被选举为新的 Leader。
副本（Replica）：
- 每个分区的副本数可以配置，副本分布在不同的 Broker 上，以提高容错性。
- 副本机制保证了数据的冗余和高可用性。

复制机制：数据被复制到多个 Broker 上，提高了数据的可用性和持久性。
Leader选举：当 Leader 节点失效时，Controller 会从 ISR 中选举一个新的 Leader。
数据恢复：新加入的 Broker 或恢复的 Broker 会从其他副本同步数据，确保数据一致性。

Kafka 2.8 引入了不依赖 Zookeeper 的架构，通过新的 Raft 协议（KRaft）管理集群元数据。

实验操作系统是：ubuntu-24.04.1，kafka版本3.8.0，是裸机，在安装了java的系统，直接跳过步骤1.

1、系统基本软件安装配置

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bat
sudo vim /etc/apt/sources.list.d/ubuntu.sources
# 选aliyun或中科大镜像之一
http://mirrors.aliyun.com/ubuntu/
http://mirrors.ustc.edu.cn/ubuntu/sudo apt-get -y update;
sudo apt-get -y upgrade;# 安装openssh-server配置远程登录
sudo apt-get install -y openssh-serversudo vi /etc/ssh/sshd_config
#添加
PermitRootLogin yessudo systemctl start ssh
sudo systemctl enable ssh# 安装中文字符
sudo apt install language-pack-zh-hans
sudo apt-get -y install fonts-liberation
sudo apt-get -y install libu2f-udev# 安装软件支持库和常用工具
sudo apt-get install -y gcc g++
sudo apt-get install -y make
sudo apt-get install -y curl
sudo apt-get install -y openjdk-8-jdk
sudo apt-get install -y subversion
sudo apt-get install -y git
sudo apt-get install -y python3
sudo apt-get install -y python3-pip
sudo apt-get install -y p7zip-full p7zip-rar
sudo apt-get install -y zip unzip

2、安装配置kafka

#创建安装目录 
mkdir -p /opt/kafka#进入安装目录
cd /opt/kafka/#下载安装包、或上传
wget https://downloads.apache.org/kafka/3.8.0/kafka_2.13-3.8.0.tgz#解压
tar -zxvf kafka_2.13-3.8.0.tgz #重命名解压的目录
mv kafka_2.13-3.8.0 kafka3.8 #进入解压目录
cd kafka3.8/#重新命名服务器节点hostname 
vi /etc/hostname
# 设置你的机器域名，如 server1
hostname server1#查看hostname
hostname# 修改配置文件，存放数据的目录：log.dirs=/opt/kafka/kafkadata/ 
# 自己设定，按i输入，修改后按esc退出修改模式，按shift+冒号后输入x保存退出编辑。
vi config/kraft/server.properties# 如果没有安装java，先装，
sudo apt-get install -y openjdk-8-jdk# 生成 UUID作为集群id，这里用临时变量KAFKA_CLUSTER_ID存储这个id： 
KAFKA_CLUSTER_ID="$(bin/kafka-storage.sh random-uuid)"# 格式化数据目录（-c指定配置文件，-t指定集群id）：
bin/kafka-storage.sh format -t $KAFKA_CLUSTER_ID -c config/kraft/server. Properties#格式化成功后，会根据 config/kraft/server.properties 的配置：log.dirs=/opt/kafka/kafkadata/
# 生成 bootstrap.checkpoint,meta.properties  里面记录着KAFKA_CLUSTER_IDls /opt/kafka/kafkadata/
bootstrap.checkpoint  meta.properties # 单节点安装完成。下面验证测试服务是否安装成功：# 启动服务 
bin/kafka-server-start.sh config/kraft/server.properties# 创建主题 testtopic
bin/kafka-topics.sh --create --topic testtopic --bootstrap-server server1:9092# 查看主题信息
bin/kafka-topics.sh --describe --topic testtopic --bootstrap-server server1:9092
bin/kafka-topics.sh --list --bootstrap-server server1:9092# 生产者，打开新终端会话发送消息
bin/kafka-console-producer.sh --topic testtopic --bootstrap-server server1:9092 # 消费者 打开另一个终端会话，订阅主题 testtopic
bin/kafka-console-consumer.sh --topic testtopic --from-beginning --bootstrap-server server1:9092

3、服务配置和集群配置

kafka提供了多种安全认证机制，主要分为SASL和SSL两大类。

SASL：是一种身份验证机制，用于在客户端和服务器之间进行身份验证的过程，其中SASL/PLAIN是基于账号密码的认证方式。
SSL：是一种加密协议，它使用公钥和私钥来建立安全的连接，并对传输的数据进行加密和解密。这里配置了kafka安全认证sasl。

配置文件 /opt/kafka/kafka3.8/config/kraft/server.properties 修改或添加如下配置
节点id，用户，密码，目录，ip和端口等信息，需要根据实际修改：

#角色
process.roles=broker,controller
node.id=1
# The connect string for the controller quorum
controller.quorum.voters=1@192.168.2.212:9093,2@192.168.2.211:9093
listeners=SASL_PLAINTEXT://192.168.2.212:9092,CONTROLLER://192.168.2.212:9093
# Name of listener used for communication between brokers.
inter.broker.listener.name=SASL_PLAINTEXT
# Listener name, hostname and port the broker will advertise to clients.
advertised.listeners=SASL_PLAINTEXT://192.168.2.212:9092
# This is required if running in KRaft mode.
controller.listener.names=CONTROLLER
# Maps listener names to security protocols, the default is for them to be the same. See the config documentation for more details
#CONTROLLER:SASL_PLAINTEXT需要修改
listener.security.protocol.map=CONTROLLER:SASL_PLAINTEXT,PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT,SASL_SSL:SASL_SSL
# 设置必须授权才能用
allow.everyone.if.no.acl.found=false
# 认证方式，用了最简单的PLAIN
sasl.mechanism.inter.broker.protocol=PLAIN
sasl.enabled.mechanisms=PLAIN
sasl.mechanism=PLAIN
# 禁用了自动创建topic
auto.create.topics.enable = false
# 设置必须授权才能用
allow.everyone.if.no.acl.found=false
# 设置超级管理员
super.users=User:admin
authorizer.class.name=org.apache.kafka.metadata.authorizer.StandardAuthorizer
# 集群间认证时用的认证方式
sasl.mechanism.controller.protocol=PLAIN
# The number of threads that the server uses for receiving requests from the network and sending responses to the network
num.network.threads=3
# The number of threads that the server uses for processing requests, which may include disk I/O
num.io.threads=8
# The send buffer (SO_SNDBUF) used by the socket server
socket.send.buffer.bytes=102400
# The receive buffer (SO_RCVBUF) used by the socket server
socket.receive.buffer.bytes=102400
# The maximum size of a request that the socket server will accept (protection against OOM)
socket.request.max.bytes=104857600
############################# Log Basics #############################
# A comma separated list of directories under which to store log files
log.dirs=/opt/kafka/kafkadata/
# The default number of log partitions per topic. More partitions allow greater
# parallelism for consumption, but this will also result in more files across
# the brokers.
num.partitions=1
# The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
# This value is recommended to be increased for installations with data dirs located in RAID array.
num.recovery.threads.per.data.dir=1
############################# Internal Topic Settings  #############################
# The replication factor for the group metadata internal topics "__consumer_offsets" and "__transaction_state"
# For anything other than development testing, a value greater than 1 is recommended to ensure availability such as 3.
offsets.topic.replication.factor=1
transaction.state.log.replication.factor=1
transaction.state.log.min.isr=1
############################# Log Retention Policy #############################
# The minimum age of a log file to be eligible for deletion due to age
log.retention.hours=168
# The maximum size of a log segment file. When this size is reached a new log segment will be created.
log.segment.bytes=1073741824
# The interval at which log segments are checked to see if they can be deleted according
# to the retention policies
log.retention.check.interval.ms=300000

配置kafka安全认证sasl

在目录 /opt/kafka/kafka3.8/config/kraft下，
创建kafka-server-sasl.properties配置文件，内容如下：

KafkaServer {org.apache.kafka.common.security.plain.PlainLoginModule requiredusername="admin"password="password"user_admin="password"user_test="test";
};

kafkaserver中定义了kafka的访问用户名密码 user_admin 必须和username password一致
特别注意分号的位置，不多不少。

修改kafka-server-start.sh，加入sasl认证，本机在/opt/kafka/kafka3.8/bin目录下。

加入环境变量：

-Djava.security.auth.login.config=/opt/kafka/kafka3.8/kafka/config/kafka-server-sasl.properties

注意：kafka-server-sasl.properties是前面添加的文件，根据自己的情况修改路径。也可以加到系统环境变量里面。

其他节点的安装，基本上是重复相同的内容，不同的是server.properties里面几处配置项，节点id和节点ip端口不同而已。

另外，集群id只要一个节点初始化即可，其他节点初始化存储目录时指定同一个集群id就可，这个集群id记录在一个元数据文件：

# 格式化数据目录（-c指定配置文件，-t指定集群id）：
bin/kafka-storage.sh format -t $KAFKA_CLUSTER_ID -c config/kraft/server. Properties
添加节点就这样加入就行了。

附：

设置系统字符编码

修改编码
1、安装相关工具
sudo apt-get update
sudo apt-get install locales2、安装 UTF-8 语言支持包
sudo locale-gen en_US.UTF-83、安装完成后，修改 /etc/default/locale 文件，将原内容清空，并输入以下内容
LANG="en_US.UTF-8"
LANGUAGE="en_US.UTF-8:"4、修改 /etc/bash.bashrc 文件，在文件的最后添加以下内容：
export LANG="en_US.UTF-8"
export LANGUAGE="en_US.UTF-8:"5、运行以下命令更新环境：
source /etc/bash.bashrc需要设置系统语言环境为中文的：
sudo update-locale LANG=zh_CN.UTF-8
sudo locale-gen

ssl生成证书的脚本：gencert.sh
变量BASE_DIR，yourpassword，域名，根据情况修改。域名需要有效域名才行。

echo "Step1: init paramters"
# your own BASE_DIR
BASE_DIR=/opt/kafka/kafka3.8/ssl
CERT_OUTPUT_PATH="$BASE_DIR/cert"
PASSWORD=yourpassword
KEY_STORE="$CERT_OUTPUT_PATH/kafka.keystore"
TRUST_STORE="$CERT_OUTPUT_PATH/kafka.truststore"
KEY_PASSWORD=$PASSWORD
STORE_PASSWORD=$PASSWORD
TRUST_KEY_PASSWORD=$PASSWORD
TRUST_STORE_PASSWORD=$PASSWORD
CLUSTER_NAME=test-cluster-01
CERT_AUTH_FILE="$CERT_OUTPUT_PATH/ca-cert"
CLUSTER_CERT_FILE="$CERT_OUTPUT_PATH/${CLUSTER_NAME}-cert"
DAYS_VALID=365
D_NAME="CN=server1, OU=yykj, O=yykj, L=China, ST=China, C=bj"
mkdir -p $CERT_OUTPUT_PATHecho "Step2: Create certificate to keystore"
keytool -keystore $KEY_STORE -alias $CLUSTER_NAME -validity $DAYS_VALID -genkey -keyalg RSA -storepass $STORE_PASSWORD -keypass $KEY_PASSWORD -dname "$D_NAME"echo "Step3: Create CA"
openssl req -new -x509 -keyout "$CERT_OUTPUT_PATH/ca-key" -out "$CERT_AUTH_FILE" -days "$DAYS_VALID" -passin pass:"$PASSWORD" -passout pass:"$PASSWORD" -subj "/C=CN/ST=XX/L=XX/O=XX/CN=XX"echo "Step4: Import CA into truststore"
keytool -keystore "$TRUST_STORE" -alias CARoot -import -file "$CERT_AUTH_FILE" -storepass "$TRUST_STORE_PASSWORD" -keypass "$TRUST_KEY_PASS" -nopromptecho "Step5: Export certificate from keystore"
keytool -keystore "$KEY_STORE" -alias "$CLUSTER_NAME" -certreq -file "$CLUSTER_CERT_FILE" -storepass "$STORE_PASSWORD" -keypass "$KEY_PASSWORD" -nopromptecho "Step6: Signing the certificate"
openssl x509 -req -CA "$CERT_AUTH_FILE" -CAkey $CERT_OUTPUT_PATH/ca-key -in "$CLUSTER_CERT_FILE" -out "${CLUSTER_CERT_FILE}-signed" -days "$DAYS_VALID" -CAcreateserial -passin pass:"$PASSWORD"echo "Setp7: Import CA into keystore"
keytool -keystore "$KEY_STORE" -alias CARoot -import -file "$CERT_AUTH_FILE" -storepass "$STORE_PASSWORD" -keypass "$KEY_PASSWORD" -nopromptecho "Setp8: Import signed certificate into keystore"
keytool -keystore "$KEY_STORE" -alias "${CLUSTER_NAME}" -import -file "${CLUSTER_CERT_FILE}-signed" -storepass "$STORE_PASSWORD" -keypass "$KEY_PASSWORD" -noprompt

修改脚本文件为可执行：
chmod 777 gencert.sh
执行脚本生成证书
./gencert.sh

ssl参考配置：

host.name=server1 
listeners=SASL_SSL://:8066,CONTROLLER://:9093
advertised.listeners=SASL_SSL://192.168.2.212:8066  
ssl.keystore.location=/opt/kafka/kafka3.8/ssl/cert/kafka.keystore
ssl.truststore.location=/opt/kafka/kafka3.8/ssl/cert/kafka.truststore
ssl.keystore.password=yourpassword
ssl.key.password=yourpassword
ssl.truststore.password=yourpassword
ssl.endpoint.identification.algorithm=
#inter.broker.listener.name=PLAINTEXT         
security.inter.broker.protocol=SASL_SSL
ssl.client.auth=required  
super.users=User:admin
sasl.enabled.mechanisms=PLAIN
sasl.mechanism.inter.broker.protocol=PLAIN
authorizer.class.name=org.apache.kafka.metadata.authorizer.StandardAuthorizer
allow.everyone.if.no.acl.found=true

springboot中集成kafka需要的包：

<dependency><groupId>org.springframework.kafka</groupId><artifactId>spring-kafka</artifactId><version>3.3.1</version></dependency>

参考maven配置：

<?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 https://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>3.4.1</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.cloud</groupId><artifactId>demo</artifactId><version>0.0.1-SNAPSHOT</version><name>demo</name><description>demo</description><properties><java.version>21</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-web</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.36</version><scope>provided</scope></dependency><dependency><groupId>org.springframework.kafka</groupId><artifactId>spring-kafka</artifactId><version>3.3.1</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

获取classpath路径：

String base = Thread.currentThread().getContextClassLoader().getResource("").toString().substring(6);

application.yml中kafka配置

server:port: 8888
spring:kafka:# 指定kafka 代理地址，可以多个bootstrap-servers: 192.168.2.212:9092,192.168.2.211:9092producer: # 生产者retries: 2 # 设置大于0的值，则客户端会将发送失败的记录重新发送# 每次批量发送消息的数量batch-size: 16384acks: alltransaction-id-prefix: kafkaTx-buffer-memory: 33554432# 指定消息key和消息体的编解码方式key-serializer: org.apache.kafka.common.serialization.StringSerializervalue-serializer: org.apache.kafka.common.serialization.StringSerializer#修改最大向kafka推送消息大小properties:max.request.size: 52428800consumer:#手动提交offset保证数据一定被消费enable-auto-commit: false#指定从最近地方开始消费(earliest)auto-offset-reset: latest#消费者组group-id: c-id-1234444334#一次调用 poll() 操作时返回的最大记录数 默认为 500 条max-poll-records: 2#如果enable.auto.commit为true，则消费者偏移自动提交给Kafka的频率（以毫秒为单位），默认值为5000  自动提交已消费offset时间间隔auto-commit-interval: 5000listener:# 在侦听器容器中运行的线程数，一般设置为 机器数*分区数concurrency: 4# 消费监听接口监听的主题不存在时，默认会报错，所以设置为false忽略错误missing-topics-fatal: false# 两次poll之间的最大间隔，默认值为5分钟。如果超过这个间隔会触发reBalancepoll-timeout: 600000properties:session:timeout:# 当broker多久没有收到consumer的心跳请求后就触发reBalance，默认值是10sms: 10000max:poll:interval:# 两次poll之间的最大间隔，默认值为5分钟。如果超过这个间隔会触发reBalancems: 600000security:protocol: SASL_PLAINTEXTsasl:mechanism: PLAINjaas:config: 'org.apache.kafka.common.security.scram.ScramLoginModule required username="admin" password="password";'

config类，注意不需要ssl协议的，请去掉相关变量：

生产者

package com.example.demo;import org.apache.kafka.clients.CommonClientConfigs;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.config.SaslConfigs;
import org.apache.kafka.common.config.SslConfigs;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;
import org.springframework.kafka.support.serializer.JsonSerializer;
import org.springframework.kafka.transaction.KafkaTransactionManager;import java.util.HashMap;
import java.util.Map;@SpringBootConfiguration
public class KafkaProviderConfig {@Value("${spring.kafka.bootstrap-servers}")private String bootstrapServers;@Value("${spring.kafka.producer.transaction-id-prefix}")private String transactionIdPrefix;@Value("${spring.kafka.producer.acks}")private String acks;@Value("${spring.kafka.producer.retries}")private String retries;@Value("${spring.kafka.producer.batch-size}")private String batchSize;@Value("${spring.kafka.producer.buffer-memory}")private String bufferMemory;@Value("${spring.kafka.admin.security.protocol}")private String securityProtocol;@Value("${spring.kafka.admin.ssl.key-store-location}")private String keystoreLocation;@Value("${spring.kafka.admin.ssl.key-store-password}")private String keystorePassword;@Value("${spring.kafka.admin.ssl.trust-store-location}")private String truststoreLocation;@Value("${spring.kafka.admin.ssl.trust-store-password}")private String truststorePassword;@Value("${spring.kafka.ssl.endpoint.identification.algorithm}")private String endpointIdentificationAlgorithm;@Value("${spring.kafka.admin.ssl.key-password}")private String keyPassword;@Value("${spring.kafka.properties.sasl.mechanism}")private String saslMechanism;@Value("${spring.kafka.properties.sasl.jaas.config}")private String jaasConfig;@Beanpublic Map<String, Object> producerConfigs() {Map<String, Object> props = new HashMap<>(16);// Thread.currentThread().getContextClassLoader().getResource("/").getPath().substring(1).replace("/", java.io.File.separator);String base = Thread.currentThread().getContextClassLoader().getResource("").toString().substring(6);props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);//acks=0 ： 生产者在成功写入消息之前不会等待任何来自服务器的响应。//acks=1 ： 只要集群的首领节点收到消息，生产者就会收到一个来自服务器成功响应。//acks=all ：只有当所有参与复制的节点全部收到消息时，生产者才会收到一个来自服务器的成功响应。//开启事务必须设为allprops.put(ProducerConfig.ACKS_CONFIG, acks);//发生错误后，消息重发的次数，开启事务必须大于0props.put(ProducerConfig.RETRIES_CONFIG, retries);props.put(ProducerConfig.BATCH_SIZE_CONFIG, batchSize);//有的时刻消息比较少,过了很久,比如5min也没有凑够16KB,这样延时就很大,所以需要一个参数. 再设置一个时间,到了这个时间,//即使数据没达到16KB,也将这个批次发送出去props.put(ProducerConfig.LINGER_MS_CONFIG, "5000");//生产者内存缓冲区的大小props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, bufferMemory);//反序列化，和生产者的序列化方式对应props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);/*props.put(CommonClientConfigs.SECURITY_PROTOCOL_CONFIG,securityProtocol);props.put(SslConfigs.SSL_KEYSTORE_LOCATION_CONFIG,base+ keystoreLocation);props.put(SslConfigs.SSL_KEYSTORE_PASSWORD_CONFIG,keystorePassword);props.put(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG,base+ truststoreLocation);props.put(SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG,truststorePassword);props.put(SslConfigs.SSL_KEYSTORE_TYPE_CONFIG,"JKS");props.put(SslConfigs.SSL_TRUSTSTORE_TYPE_CONFIG,"JKS");props.put(SslConfigs.SSL_KEY_PASSWORD_CONFIG,keyPassword);props.put(SslConfigs.SSL_ENDPOINT_IDENTIFICATION_ALGORITHM_CONFIG,endpointIdentificationAlgorithm);*/props.put(SaslConfigs.SASL_MECHANISM, saslMechanism);props.put(SaslConfigs.SASL_JAAS_CONFIG,jaasConfig);return props;}@Beanpublic ProducerFactory<Object, Object> producerFactory() {DefaultKafkaProducerFactory<Object, Object> factory = new DefaultKafkaProducerFactory<>(producerConfigs());//开启事务，会导致 LINGER_MS_CONFIG 配置失效factory.setTransactionIdPrefix(transactionIdPrefix);return factory;}@Beanpublic KafkaTransactionManager<Object, Object> kafkaTransactionManager(ProducerFactory<Object, Object> producerFactory) {return new KafkaTransactionManager<>(producerFactory);}@Beanpublic KafkaTemplate<Object, Object> kafkaTemplate() {return new KafkaTemplate<>(producerFactory());}
}

消费者

package com.example.demo;import org.apache.kafka.clients.CommonClientConfigs;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.common.config.SaslConfigs;
import org.apache.kafka.common.config.SslConfigs;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.core.ConsumerFactory;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
import org.springframework.kafka.listener.ContainerProperties;
import org.springframework.kafka.support.serializer.JsonDeserializer;import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;@SpringBootConfiguration
public class KafkaConsumerConfig {@Value("${spring.kafka.bootstrap-servers}")private String bootstrapServers;@Value("${spring.kafka.consumer.group-id}")private String groupId;@Value("${spring.kafka.consumer.enable-auto-commit}")private boolean enableAutoCommit;@Value("${spring.kafka.consumer.max-poll-records}")private String maxPollRecords;@Value("${spring.kafka.consumer.auto-offset-reset}")private String autoOffsetReset;@Value("${spring.kafka.properties.session.timeout.ms}")private String sessionTimeout;@Value("${spring.kafka.properties.max.poll.interval.ms}")private String maxPollIntervalTime;@Value("${spring.kafka.listener.concurrency}")private Integer concurrency;@Value("${spring.kafka.listener.missing-topics-fatal}")private boolean missingTopicsFatal;@Value("${spring.kafka.listener.poll-timeout}")private long pollTimeout;@Value("${spring.kafka.admin.security.protocol}")private String securityProtocol;@Value("${spring.kafka.admin.ssl.key-store-location}")private String keystoreLocation;@Value("${spring.kafka.admin.ssl.key-store-password}")private String keystorePassword;@Value("${spring.kafka.admin.ssl.trust-store-location}")private String truststoreLocation;@Value("${spring.kafka.admin.ssl.trust-store-password}")private String truststorePassword;@Value("${spring.kafka.ssl.endpoint.identification.algorithm}")private String endpointIdentificationAlgorithm;@Value("${spring.kafka.admin.ssl.key-password}")private String keyPassword;@Value("${spring.kafka.properties.sasl.mechanism}")private String saslMechanism;@Value("${spring.kafka.properties.sasl.jaas.config}")private String jaasConfig;@Beanpublic Map<String, Object> consumerConfigs() {Map<String, Object> props = new HashMap<>(16);// 需要去掉路径前缀// Thread.currentThread().getContextClassLoader().getResource("/").getPath().substring(1).replace("/", java.io.File.separator);String base = Thread.currentThread().getContextClassLoader().getResource("").toString().substring(6);props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);//是否自动提交偏移量，默认值是true，为了避免出现重复数据和数据丢失，可以把它设置为false，然后手动提交偏移量props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, enableAutoCommit);//自动提交的时间间隔，自动提交开启时生效props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "2000");//该属性指定了消费者在读取一个没有偏移量的分区或者偏移量无效的情况下该作何处理：props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, autoOffsetReset);//两次poll之间的最大间隔，默认值为5分钟。如果超过这个间隔会触发reBalanceprops.put(ConsumerConfig.MAX_POLL_INTERVAL_MS_CONFIG, maxPollIntervalTime);props.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG, maxPollRecords);//当broker多久没有收到consumer的心跳请求后就触发reBalance，默认值是10sprops.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, sessionTimeout);//序列化（建议使用Json，这种序列化方式可以无需额外配置传输实体类）props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);/*props.put(CommonClientConfigs.SECURITY_PROTOCOL_CONFIG,securityProtocol);props.put(SslConfigs.SSL_KEYSTORE_LOCATION_CONFIG,base+ keystoreLocation);props.put(SslConfigs.SSL_KEYSTORE_PASSWORD_CONFIG,keystorePassword);props.put(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG,base+ truststoreLocation);props.put(SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG,truststorePassword);props.put(SslConfigs.SSL_KEYSTORE_TYPE_CONFIG,"JKS");props.put(SslConfigs.SSL_TRUSTSTORE_TYPE_CONFIG,"JKS");props.put(SslConfigs.SSL_KEY_PASSWORD_CONFIG,keyPassword);props.put(SslConfigs.SSL_ENDPOINT_IDENTIFICATION_ALGORITHM_CONFIG,endpointIdentificationAlgorithm);*/props.put(SaslConfigs.SASL_MECHANISM, saslMechanism);props.put(SaslConfigs.SASL_JAAS_CONFIG,jaasConfig);return props;}@Beanpublic ConsumerFactory<Object, Object> consumerFactory() {//配置消费者的 Json 反序列化的可信赖包，反序列化实体类需要try(JsonDeserializer<Object> deserializer = new JsonDeserializer<>()) {deserializer.trustedPackages("*");return new DefaultKafkaConsumerFactory<>(consumerConfigs(), new JsonDeserializer<>(), deserializer);}}@Bean(name="containerFactory1")public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<Object, Object>> kafkaListenerContainerFactory() {ConcurrentKafkaListenerContainerFactory<Object, Object> factory = new ConcurrentKafkaListenerContainerFactory<>();factory.setConsumerFactory(consumerFactory());//在侦听器容器中运行的线程数，一般设置为 机器数*分区数factory.setConcurrency(concurrency);//消费监听接口监听的主题不存在时，默认会报错，所以设置为false忽略错误factory.setMissingTopicsFatal(missingTopicsFatal);//自动提交关闭，需要设置手动消息确认factory.getContainerProperties().setAckMode(ContainerProperties.AckMode.MANUAL_IMMEDIATE);factory.getContainerProperties().setPollTimeout(pollTimeout);//设置为批量监听，需要用List接收//factory.setBatchListener(true);return factory;}
}

发送消息，注意需要springboot-web依赖，看前面的maven依赖：

package com.example.demo;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
@RequestMapping("/kafka")
//这个注解代表这个类开启Springboot事务
@Transactional(rollbackFor = RuntimeException.class)
public class KafkaController {@Autowiredprivate KafkaTemplate<Object, Object> kafkaTemplate;@RequestMapping("/sendMultiple")public void sendMultiple() {for (int i = 0;i < 10;i++) {kafkaTemplate.send("testtopic1", "你好 world " + (i+1));}}@RequestMapping("/send")public String send() {kafkaTemplate.send("testtopic1", "你好 world.。");return "send ok";}
}

package com.example.demo;import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.springframework.kafka.support.ProducerListener;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;@Component
public class KafkaSendResultHandler implements ProducerListener<Object, Object> {@Overridepublic void onSuccess(ProducerRecord producerRecord, RecordMetadata recordMetadata) {System.out.println("消息发送成功：" + producerRecord.toString());}@Overridepublic void onError(ProducerRecord producerRecord, @Nullable RecordMetadata recordMetadata, Exception exception) {System.out.println("消息发送失败：" + producerRecord.toString() + exception.getMessage());}
}

消费消息

package com.example.demo;import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;@Component
public class KafkaHandler {@KafkaListener(groupId = "c-id-1234444334", topics = "testtopic1")//这里写业务逻辑public void listen(String message) {System.out.println("收到消息: "+message);}
}

异常处理

package com.example.demo;import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.Consumer;
import org.springframework.kafka.listener.KafkaListenerErrorHandler;
import org.springframework.kafka.listener.ListenerExecutionFailedException;
import org.springframework.lang.NonNull;
import org.springframework.messaging.Message;
import org.springframework.stereotype.Component;@Component
@Slf4j
public class KafkaErrorHandler implements KafkaListenerErrorHandler {@Override@NonNullpublic Object handleError(@NonNull Message<?> message, @NonNull ListenerExecutionFailedException exception) {return new Object();}@Override@NonNullpublic Object handleError(@NonNull Message<?> message, @NonNull ListenerExecutionFailedException exception, Consumer<?, ?> consumer) {return KafkaListenerErrorHandler.super.handleError(message, exception, consumer);}
}