#yyds干货盘点#将CSV的数据发送到kafka(java版)

春衣少年当酒歌,起舞四顾以笑和。这篇文章主要讲述#yyds干货盘点#将CSV的数据发送到kafka(java版)相关的知识,希望能为你提供帮助。
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列名称 说明
用户ID 整数类型,序列化后的用户ID
商品ID 整数类型,序列化后的商品ID
商品类目ID 整数类型,序列化后的商品所属类目ID
行为类型 字符串,枚举类型,包括(pv, buy, cart, fav)
时间戳 行为发生的时间戳
时间字符串 根据时间戳字段生成的时间字符串
  1. 关于该数据集的详情,请参考《准备数据集用于flink学习》
    java应用简介
    编码前,先把具体内容列出来,然后再挨个实现:
  2. 从CSV读取记录的工具类:UserBehaviorCsvFileReader
  3. 每条记录对应的Bean类:UserBehavior
  4. Java对象序列化成JSON的序列化类:JsonSerializer
  5. 向kafka发送消息的工具类:KafkaProducer
  6. 应用类,程序入口:SendMessageApplication
上述五个类即可完成Java应用的工作,接下来开始编码吧;
直接下载源码
  1. 如果您不想写代码,您可以直接从GitHub下载这个工程的源码,地址和链接信息如下表所示:
名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议
  1. 这个git项目中有多个文件夹,本章源码在flinksql这个文件夹下,如下图红框所示:
    #yyds干货盘点#将CSV的数据发送到kafka(java版)

    文章图片
    编码
  2. 创建maven工程,pom.xml如下,比较重要的jackson和javacsv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.bolingcavalry< /groupId> < artifactId> flinksql< /artifactId> < version> 1.0-SNAPSHOT< /version> < properties> < project.build.sourceEncoding> UTF-8< /project.build.sourceEncoding> < flink.version> 1.10.0< /flink.version> < kafka.version> 2.2.0< /kafka.version> < java.version> 1.8< /java.version> < scala.binary.version> 2.11< /scala.binary.version> < maven.compiler.source> $java.version< /maven.compiler.source> < maven.compiler.target> $java.version< /maven.compiler.target> < /properties> < dependencies> < dependency> < groupId> org.apache.kafka< /groupId> < artifactId> kafka-clients< /artifactId> < version> $kafka.version< /version> < /dependency> < dependency> < groupId> com.fasterxml.jackson.core< /groupId> < artifactId> jackson-databind< /artifactId> < version> 2.9.10.1< /version> < /dependency> < !-- Logging dependencies --> < dependency> < groupId> org.slf4j< /groupId> < artifactId> slf4j-log4j12< /artifactId> < version> 1.7.7< /version> < scope> runtime< /scope> < /dependency> < dependency> < groupId> log4j< /groupId> < artifactId> log4j< /artifactId> < version> 1.2.17< /version> < scope> runtime< /scope> < /dependency> < dependency> < groupId> net.sourceforge.javacsv< /groupId> < artifactId> javacsv< /artifactId> < version> 2.0< /version> < /dependency> < /dependencies> < build> < plugins> < !-- Java Compiler --> < plugin> < groupId> org.apache.maven.plugins< /groupId> < artifactId> maven-compiler-plugin< /artifactId> < version> 3.1< /version> < configuration> < source> $java.version< /source> < target> $java.version< /target> < /configuration> < /plugin> < !-- Shade plugin to include all dependencies --> < plugin> < groupId> org.apache.maven.plugins< /groupId> < artifactId> maven-shade-plugin< /artifactId> < version> 3.0.0< /version> < executions> < !-- Run shade goal on package phase --> < execution> < phase> package< /phase> < goals> < goal> shade< /goal> < /goals> < configuration> < artifactSet> < excludes> < /excludes> < /artifactSet> < filters> < filter> < !-- Do not copy the signatures in the META-INF folder. Otherwise, this might cause SecurityExceptions when using the JAR. --> < artifact> *:*< /artifact> < excludes> < exclude> META-INF/*.SF< /exclude> < exclude> META-INF/*.DSA< /exclude> < exclude> META-INF/*.RSA< /exclude> < /excludes> < /filter> < /filters> < /configuration> < /execution> < /executions> < /plugin> < /plugins> < /build> < /project>

  3. 从CSV读取记录的工具类:==UserBehaviorCsvFileReader==,后面在主程序中会用到java8的Steam API来处理集合,所以UserBehaviorCsvFileReader实现了Supplier接口:
    public class UserBehaviorCsvFileReader implements Supplier< UserBehavior> private final String filePath; private CsvReader csvReader; public UserBehaviorCsvFileReader(String filePath) throws IOException this.filePath = filePath; try csvReader = new CsvReader(filePath); csvReader.readHeaders(); catch (IOException e) throw new IOException("Error reading TaxiRecords from file: " + filePath, e); @Override public UserBehavior get() UserBehavior userBehavior = null; try if(csvReader.readRecord()) csvReader.getRawRecord(); userBehavior = new UserBehavior( Long.valueOf(csvReader.get(0)), Long.valueOf(csvReader.get(1)), Long.valueOf(csvReader.get(2)), csvReader.get(3), new Date(Long.valueOf(csvReader.get(4))*1000L)); catch (IOException e) throw new NoSuchElementException("IOException from " + filePath); if (null==userBehavior) throw new NoSuchElementException("All records read from " + filePath); return userBehavior;

  4. 【#yyds干货盘点#将CSV的数据发送到kafka(java版)】每条记录对应的Bean类:==UserBehavior==,和CSV记录格式保持一致即可,表示时间的==ts==字段,使用了JsonFormat注解,在序列化的时候以此来控制格式:
    public class UserBehavior @JsonFormat private long user_id; @JsonFormat private long item_id; @JsonFormat private long category_id; @JsonFormat private String behavior; @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-ddTHH:mm:ssZ") private Date ts; public UserBehavior() public UserBehavior(long user_id, long item_id, long category_id, String behavior, Date ts) this.user_id = user_id; this.item_id = item_id; this.category_id = category_id; this.behavior = behavior; this.ts = ts;

  5. Java对象序列化成JSON的序列化类:JsonSerializer
    public class JsonSerializer< T> private final ObjectMapper jsonMapper = new ObjectMapper(); public String toJSONString(T r) try return jsonMapper.writeValueAsString(r); catch (JsonProcessingException e) throw new IllegalArgumentException("Could not serialize record: " + r, e); public byte[] toJSONBytes(T r) try return jsonMapper.writeValueAsBytes(r); catch (JsonProcessingException e) throw new IllegalArgumentException("Could not serialize record: " + r, e);

  6. 向kafka发送消息的工具类:==KafkaProducer==:
    public class KafkaProducer implements Consumer< UserBehavior> private final String topic; private final org.apache.kafka.clients.producer.KafkaProducer< byte[], byte[]> producer; private final JsonSerializer< UserBehavior> serializer; public KafkaProducer(String kafkaTopic, String kafkaBrokers) this.topic = kafkaTopic; this.producer = new org.apache.kafka.clients.producer.KafkaProducer< > (createKafkaProperties(kafkaBrokers)); this.serializer = new JsonSerializer< > (); @Override public void accept(UserBehavior record) // 将对象序列化成byte数组 byte[] data = https://www.songbingjia.com/android/serializer.toJSONBytes(record); // 封装 ProducerRecord< byte[], byte[]> kafkaRecord = new ProducerRecord< > (topic, data); // 发送 producer.send(kafkaRecord); // 通过sleep控制消息的速度,请依据自身kafka配置以及flink服务器配置来调整 try Thread.sleep(500); catch(InterruptedException e) e.printStackTrace(); /** * kafka配置 * @param brokers The brokers to connect to. * @return A Kafka producer configuration. */ private static Properties createKafkaProperties(String brokers) Properties kafkaProps = new Properties(); kafkaProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, brokers); kafkaProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class.getCanonicalName()); kafkaProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class.getCanonicalName()); return kafkaProps;

  7. 最后是应用类SendMessageApplication,CSV文件路径、kafka的topic和borker地址都在此设置,另外借助java8的Stream API,只需少量代码即可完成所有工作:
    public class SendMessageApplication public static void main(String[] args) throws Exception // 文件地址 String filePath = "D:\\\\temp\\\\202005\\\\02\\\\UserBehavior.csv"; // kafka topic String topic = "user_behavior"; // kafka borker地址 String broker = "192.168.50.43:9092"; Stream.generate(new UserBehaviorCsvFileReader(filePath)) .sequential() .forEachOrdered(new KafkaProducer(topic, broker));

验证
  1. 请确保kafka已经就绪,并且名为==user_behavior==的topic已经创建;
  2. 请将CSV文件准备好;
  3. 确认SendMessageApplication.java中的文件地址、kafka topic、kafka broker三个参数准确无误;
  4. 运行SendMessageApplication.java;
  5. 开启一个 控制台消息kafka消息,参考命令如下:
    ./kafka-console-consumer.sh \\ --bootstrap-server 127.0.0.1:9092 \\ --topic user_behavior \\ --consumer-property group.id=old-consumer-test \\ --consumer-property consumer.id=old-consumer-cl \\ --from-beginning

  6. 正常情况下可以立即见到消息,如下图:
    #yyds干货盘点#将CSV的数据发送到kafka(java版)

    文章图片

    至此,通过Java应用模拟用户行为消息流的操作就完成了,接下来的flink实战就用这个作为数据源;
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