我正在尝试使用spring云流框架构建一个简单的kafka流应用程序。我可以连接到流以推送原始数据进行处理。但是,当我尝试处理流以便按键进行事件计数时,我得到 Serde class not found: org.apache.kafka.common.serialization.Serde$StringSerde
运行应用程序时出现异常。我检查了我的项目包括图书馆,我可以找到 Serde
同学们,它没有丢失。我不知道为什么在运行时它没有被加载!
下面是我的源文件。 com.pgp.learn.kafka.analytics.AnalyticsApplication
```
package com.pgp.learn.kafka.analytics;
import com.pgp.learn.kafka.analytics.model.PageViewEvent;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.streams.KeyValue;
import org.apache.kafka.streams.kstream.*;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.stream.annotation.EnableBinding;
import org.springframework.cloud.stream.annotation.Input;
import org.springframework.cloud.stream.annotation.StreamListener;
import org.springframework.kafka.support.KafkaHeaders;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
@SpringBootApplication
@EnableBinding(AnalyticsBinding.class)
public class AnalyticsApplication {
public static void main(String[] args) {
SpringApplication.run(AnalyticsApplication.class, args);
}
@Component
public static class PageViewEventSource implements ApplicationRunner {
private final MessageChannel pageViewOut;
private final Log log = LogFactory.getLog(getClass());
public PageViewEventSource(AnalyticsBinding binding) {
this.pageViewOut = binding.pageViewsOut();
}
@Override
public void run(ApplicationArguments args) throws Exception {
List<String> names = Arrays.asList("Peter", "Tom", "Ady", "Nency", "George", "Kevin", "Chelsey", "Thomas");
List<String> pages = Arrays.asList("About", "Contact", "Blogs", "Gallery", "Music", "Site-map", "News");
Runnable runner = () -> {
String rName = names.get(new Random().nextInt(names.size()));
String rPage = pages.get(new Random().nextInt(pages.size()));
PageViewEvent event = new PageViewEvent(rName, rPage, Math.random() > .5 ? 10L : 1000L);
Message<PageViewEvent> message = MessageBuilder
.withPayload(event)
.setHeader(KafkaHeaders.MESSAGE_KEY, event.getUserId().getBytes())
.build();
try {
this.pageViewOut.send(message);
log.info("Sent: " + message.toString());
} catch (Exception e) {
log.error(e);
}
};
Executors.newScheduledThreadPool(1).scheduleAtFixedRate(runner, 1, 1, TimeUnit.SECONDS);
}
}
@Component
public static class PageViewEventProcessor {
private final Log log = LogFactory.getLog(getClass());
@StreamListener
@SendTo(AnalyticsBinding.PAGE_COUNT_OUT)
public static KStream<String, Long> process(
@Input(AnalyticsBinding.PAGE_VIEW_IN_CHANNEL) KStream<String, PageViewEvent> events) {
return events
.filter((s, pageViewEvent) -> pageViewEvent.getDuration() > 10)
.map((s, pageViewEvent) -> new KeyValue<>(pageViewEvent.getPage(), 0L))
.groupByKey()
//Also tried using below line, but no luck
//.groupByKey(Serialized.with(Serdes.String(), Serdes.Long()))
.count(Materialized.as(AnalyticsBinding.PAGE_COUNT_MV))
.toStream();
}
}
}`com.pgp.learn.kafka.analytics.AnalyticsBinding`
package com.pgp.learn.kafka.analytics;
import com.pgp.learn.kafka.analytics.model.PageViewEvent;
import org.apache.kafka.streams.kstream.KStream;
import org.springframework.cloud.stream.annotation.Input;
import org.springframework.cloud.stream.annotation.Output;
import org.springframework.messaging.MessageChannel;
public interface AnalyticsBinding {
String PAGE_VIEW_OUT_CHANNEL = "pvout";
String PAGE_VIEW_IN_CHANNEL = "pvin";
String PAGE_COUNT_MV = "pcmvc";
String PAGE_COUNT_OUT = "pcout";
String PAGE_COUNT_IN = "pcin";
@Input (PAGE_VIEW_IN_CHANNEL)
KStream<String, PageViewEvent> pageViewsIn();
@Output (PAGE_VIEW_OUT_CHANNEL)
MessageChannel pageViewsOut();
@Output (PAGE_COUNT_OUT)
KStream<String, Long> pageCountOut();
}`application.properties`
defaults
spring.cloud.stream.kafka.streams.binder.configuration.commit.interval.mms=1000
spring.cloud.stream.kafka.streams.binder.configuration.default.key.serde=org.apache.kafka.common.serialization.Serde$StringSerde
spring.cloud.stream.kafka.streams.binder.configuration.default.value.serde=org.apache.kafka.common.serialization.Serde$StringSerde
spring.cloud.stream.kafka.binder.brokers=54.173.206.255
page views out
spring.cloud.stream.bindings.pvout.destination=pvs
spring.cloud.stream.bindings.pvout.producer.header-mode=raw
page views in
spring.cloud.stream.bindings.pvin.destination=pvs
spring.cloud.stream.bindings.pvin.consumer.header-mode=raw
page count out
spring.cloud.stream.bindings.pcout.destination=pcs
spring.cloud.stream.bindings.pcout.producer.use-native-encoding=true
spring.cloud.stream.kafka.streams.bindings.pcout.producer.keySerde=org.apache.kafka.common.serialization.Serdes$StringSerde
spring.cloud.stream.kafka.streams.bindings.pcout.producer.valueSerde=org.apache.kafka.common.serialization.Serdes$LongSerde`pom.xml`
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.1.1.RELEASE
com.pgp.learn.kafka
analytics
0.0.1-SNAPSHOT
analytics
Demo project for Spring Boot
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.RC2</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-binder-kafka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-binder-kafka-streams</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-test-support</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</repository>
</repositories>
1条答案
按热度按时间vu8f3i0k1#
您的配置属性中有一个输入错误:
spring.cloud.stream.kafka.streams.binder.configuration.default.key.serde=org.apache.kafka.common.serialization.Serde$StringSerde
在塞德找不到“s”。应该是...serialization.Serdes$StringSerde