kafka学习（五）Spring Boot 整合 Kafka

一、创建Spring boot 工程

创建过程不再描述，创建后的工程结构如下：

POM文件中要加入几个依赖：

<?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 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>2.1.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.zhbf</groupId>
    <artifactId>springboot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--引入kafka依赖-->
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
        <!-- 添加 gson 依赖 -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.5</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

启动SpringbootApplication.java，出现下图界面则说明工程创建好了：

二、创建kafka生产者类，并通过控制器调用

kafka生产者类

/**
 * Kafka消息生产类
 */
@Log
@Component
public class KafkaProducer {

    @Resource
    private KafkaTemplate<String, String> kafkaTemplate;

    @Value("${kafka.topic.user}")
    private String topicUser;//topic名称

    /**
     * 发送用户消息
     *
     * @param user 用户信息
     */
    public void sendUserMessage(User user) {
        GsonBuilder builder = new GsonBuilder();
        builder.setPrettyPrinting();
        builder.setDateFormat("yyyy-MM-dd HH:mm:ss");
        String message = builder.create().toJson(user);
        kafkaTemplate.send(topicUser, message);
        log.info("\n生产消息至Kafka\n" + message);
    }
}

application.yml配置文件

启动ZK、kafka通讯的服务器broker，并启动消费者监听

　　启动方式参考上一篇文章，戳这里~

配置一个控制器，即调用kafka生成消息的入口

/**
 * 测试控制器
 * PS:@RestController 注解： 该注解是 @Controller 和 @ResponseBody 注解的合体版
 */
@RestController
@RequestMapping("/kafka")
public class KafkaController {

    @Autowired
    private User user;

    @Autowired
    private KafkaProducer kafkaProducer;

    @RequestMapping("/createMsg")
    public void createMsg() {
        kafkaProducer.sendUserMessage(user);
    }
}

启动SpringbootApplication，并通过浏览器访问控制器，生成消息

 

 

可以看到控制台和消费者窗口都打印了kafka生成的消息。

三、创建kafka消费者类，并通过控制器调用

 kafka消费者类

@Log
@Component
public class KafkaConsumerDemo {

    public void consume() {
        Properties props = new Properties();

        // 必须设置的属性
        props.put("bootstrap.servers", "127.0.0.1:9092");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("group.id", "group-user");

        // 可选设置属性
        props.put("enable.auto.commit", "true");
        // 自动提交offset,每1s提交一次
        props.put("auto.commit.interval.ms", "1000");
        props.put("auto.offset.reset", "earliest ");
        props.put("client.id", "zy_client_id");
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        // 订阅test1 topic
        consumer.subscribe(Collections.singletonList("topic-user"));

        while (true) {
            //  从服务器开始拉取数据
            ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
            records.forEach(record -> {
                System.out.printf("成功消费消息：topic = %s ,partition = %d,offset = %d, key = %s, value = %s%n", record.topic(), record.partition(),
                        record.offset(), record.key(), record.value());
            });
        }
    }
}

重启SpringbootApplication，并通过浏览器访问控制器，消费消息

 

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