每天学习一点点 编程PDF电子书、视频教程免费下载:
http://www.shitanlife.com/code
创建一个kafka-producer-master的maven工程。整个项目结构如下:
Maven的依赖
<?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>com.gzh.kafka.producer</groupId>
<artifactId>producer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging> <name>kafka-producer-master</name>
<description>demo project for kafka producer</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-kafka.version>2.1.5.RELEASE</spring-kafka.version>
<java.version>1.8</java.version>
</properties> <dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency> <!-- https://mvnrepository.com/artifact/org.springframework.kafka/spring-kafka -->
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
<version>${spring-kafka.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.kafka/spring-kafka-test -->
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka-test</artifactId>
<version>${spring-kafka.version}</version>
<scope>test</scope>
</dependency> <!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger2 -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.8.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger-ui -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.8.0</version>
</dependency> </dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build> </project>
使用application.properties配置应用程序
当然,根据个人喜好,你也可以使用application.yml属性文件重写配置。Spring Boot会尝试根据pom.xml文件中指定的依赖关系自动配置应用程序,并设置合理的默认值。
server.port=8000
spring.application.name=kafka-producer
#kafka configuration
spring.kafka.producer.bootstrap-servers=192.168.1.130:9092,192.168.1.101:9093,192.168.1.101:9094
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
#topic
kafka.app.topic.foo=test20180430
在上面的配置中,我给生产者分配的端口号是8000,服务器有3台,采用先前window环境搭建zookeeper,kafka集群 中配置的服务器。想了解关于kafka生产者相关的更多配置的话,可以阅读关于Spring Boot Kafka Properties的配置信息。
使用Spring Boot发送Spring Kafka消息
SpringKafka提供了使用Producer的KafkaTemplate类发送消息,并提供将数据发送到Kafka主题的高级操作。 提供异步和同步方法,异步方法返回Future。Spring Boot根据application.properties属性文件中配置的属性自动配置并初始化KafkaTemplate。为了方便测试发送消息,使用了Spring的定时任务,在类上使用@EnableScheduling 注解开启定时任务,通过@Scheduled注解指定发送消息规则。
package com.gzh.kafka.producer.component; import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import org.springframework.util.concurrent.ListenableFuture; @Component
@EnableScheduling
public class KafkaMessageProducer { private static final Logger LOG = LoggerFactory.getLogger(KafkaMessageProducer.class); @Autowired
private KafkaTemplate<String, String> kafkaTemplate; @Value("${kafka.app.topic.foo}")
private String topic; @Scheduled(cron = "00/5 * * * * ?")
public void send() {
String message = "Hello World---" + System.currentTimeMillis();
LOG.info("topic="+topic+",message="+message);
ListenableFuture<SendResult<String, String>> future = kafkaTemplate.send(topic, message);
future.addCallback(success -> LOG.info("KafkaMessageProducer 发送消息成功!"),
fail -> LOG.error("KafkaMessageProducer 发送消息失败!"));
}
}
创建消息生产者启动类
package com.gzh.kafka.producer; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties; @SpringBootApplication
@EnableConfigurationProperties
public class KafkaProducerApplication{ public static void main(String[] args) {
SpringApplication.run(KafkaProducerApplication.class, args);
}
}
至此,Spring Boot整合Spring Kafka消息生产者应用已经整合完毕。启动zookeeper、kafka各个服务器。启动生产者应用,查看消息生产者应用控制台日志,如下图说明整合OK。
当然在创建消息生产者类时,我们可以更加灵活,可以不使用定时任务,通过界面请求的方式,发送我们想要发送的内容。简单案例如下:
- 消息发送者类
package com.gzh.kafka.producer.service; import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.stereotype.Service;
import org.springframework.util.concurrent.ListenableFuture; @Service
public class KafkaMessageSendService { private static final Logger LOG = LoggerFactory.getLogger(KafkaMessageSendService.class); @Autowired
private KafkaTemplate<String, String> kafkaTemplate; @Value("${kafka.app.topic.foo}")
private String topic; public void send(String message){
LOG.info("topic="+topic+",message="+message);
ListenableFuture<SendResult<String, String>> future = kafkaTemplate.send(topic, message);
future.addCallback(success -> LOG.info("KafkaMessageProducer 发送消息成功!"),
fail -> LOG.error("KafkaMessageProducer 发送消息失败!"));
}
}
- 界面请求处理controller类
package com.gzh.kafka.producer.controller; import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController; import com.gzh.kafka.producer.service.KafkaMessageSendService; @RestController
@RequestMapping(value="send",produces=MediaType.APPLICATION_JSON_UTF8_VALUE)
public class KafkaMessageSendController { @Autowired
private KafkaMessageSendService kafkaMessageSendService; @RequestMapping(value="/sendMessage",method=RequestMethod.POST)
public String send(@RequestParam(required=true) String message){
try {
kafkaMessageSendService.send(message);
} catch (Exception e) {
return "send failed.";
}
return message;
}
}
- 通过Swagger访问测试Controller服务请求
Spring Kafka整合Spring Boot创建消费者客户端案例:
创建一个kafka-consumer-master的maven工程。整个项目结构如下:
Maven的依赖
<?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>com.gzh.kafka.consumer</groupId>
<artifactId>consumer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging> <name>kafka-consumer-master</name>
<description>demo project for kafka consumer</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-kafka.version>1.3.4.RELEASE</spring-kafka.version>
<java.version>1.8</java.version>
</properties> <dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.kafka/spring-kafka -->
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
<version>${spring-kafka.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.kafka/spring-kafka-test -->
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka-test</artifactId>
<version>${spring-kafka.version}</version>
<scope>test</scope>
</dependency>
</dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build> </project>
注意,这是使用Spring-Kafka时一定要注意版本问题,否则会报各种奇葩错误。Spring官方网站上给出了SpringKafka和kafka-client版本(它的版本号要和kafka服务器的版本保持一致)的对应关系:
使用application.properties配置应用程序
Spring Boot会尝试根据pom.xml文件中指定的依赖关系自动配置应用程序,并设置合理的默认值。
server.port=8001
spring.application.name=kafka-consumer #kafka configuration
#指定消息被消费之后自动提交偏移量,以便下次继续消费
spring.kafka.consumer.enable-auto-commit=true
#指定消息组
spring.kafka.consumer.group-id=guan
#指定kafka服务器地址
spring.kafka.consumer.bootstrap-servers=192.168.1.130:9092,192.168.1.101:9093,192.168.1.101:9094
#指定从最近地方开始消费(earliest)
spring.kafka.consumer.auto-offset-reset=latest spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer
#topic
kafka.app.topic.foo=test20180430
在上面的配置中,我给生产者分配的端口号是8000,服务器有3台,采用先前window环境搭建zookeeper,kafka集群 中配置的服务器。想了解关于kafka生产者相关的更多配置的话,可以阅读关于Spring Boot Kafka Properties的配置信息。
使用Spring Boot消费Spring Kafka消息
通过使用@KafkaListener来注解一个方法Spring Kafka会自动创建一个消息监听器容器。使用该注解,并指定要消费的topic(也可以指定消费组以及分区号,支持正则表达式匹配),这样,消费者一旦启动,就会监听kafka服务器上的topic,实时进行消费消息。
package com.gzh.kafka.consumer.service; import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.handler.annotation.Headers;
import org.springframework.messaging.handler.annotation.Payload;
import org.springframework.stereotype.Component; @Component
public class KafkaMessageConsumer { private static final Logger LOG = LoggerFactory.getLogger(KafkaMessageConsumer.class); @KafkaListener(topics={"${kafka.app.topic.foo}"})
public void receive(@Payload String message, @Headers MessageHeaders headers){
LOG.info("KafkaMessageConsumer 接收到消息:"+message);
headers.keySet().forEach(key->LOG.info("{}: {}",key,headers.get(key)));
}
}
创建消息消费者启动类
package com.gzh.kafka.consumer; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties; @SpringBootApplication
@EnableConfigurationProperties
public class KafkaConsumerApplication { public static void main(String[] args) {
SpringApplication.run(KafkaConsumerApplication.class, args);
}
}
消费者应用已经完成,接下来让我们验证Spring Kafka消息发送和接收效果。先依次启动zookeeper、kafka服务器,然后在启动生产者(kafka-producer-master)应用,再启动消费者(kafka-consumer-master)应用,然后观察生产者和消费者启动类日志: