使用Flink实现Kafka到MySQL的数据流转换
在现代数据处理架构中,Kafka和MySQL是两种非常流行的技术。Kafka作为一个高吞吐量的分布式消息系统,常用于构建实时数据流管道。而MySQL则是广泛使用的关系型数据库,适用于存储和查询数据。在某些场景下,我们需要将Kafka中的数据实时地写入到MySQL数据库中,本文将介绍如何使用Apache Flink来实现这一过程。
环境准备
在开始之前,请确保你的开发环境中已经安装并配置了以下组件:
Apache Flink 准备相关pom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>org.example</groupId><artifactId>EastMoney</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>org.apache.flink</groupId><artifactId>flink-clients_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-api-scala-bridge_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-planner_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-api-scala_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-connector-jdbc_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-csv</artifactId><version>1.14.0</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-connector-kafka_2.11</artifactId><version>1.14.0</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.25</version></dependency></dependencies></project>
Kafka消息队列
1. 启动zookeeperzkServer start
2. 启动kafka服务kafka-server-start /opt/homebrew/etc/kafka/server.properties
3. 创建topickafka-topics --create --bootstrap-server 127.0.0.1:9092 --replication-factor 1 --partitions 1 --topic east_money
6. 生产数据kafka-console-producer --broker-list localhost:9092 --topic east_money
MySQL数据库
初始化mysql表
CREATE TABLE `t_stock_code_price` (`id` bigint NOT NULL AUTO_INCREMENT,`code` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '股票代码',`name` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '股票名称',`close` double DEFAULT NULL COMMENT '最新价',`change_percent` double DEFAULT NULL COMMENT '涨跌幅',`change` double DEFAULT NULL COMMENT '涨跌额',`volume` double DEFAULT NULL COMMENT '成交量(手)',`amount` double DEFAULT NULL COMMENT '成交额',`amplitude` double DEFAULT NULL COMMENT '振幅',`turnover_rate` double DEFAULT NULL COMMENT '换手率',`peration` double DEFAULT NULL COMMENT '市盈率',`volume_rate` double DEFAULT NULL COMMENT '量比',`hign` double DEFAULT NULL COMMENT '最高',`low` double DEFAULT NULL COMMENT '最低',`open` double DEFAULT NULL COMMENT '今开',`previous_close` double DEFAULT NULL COMMENT '昨收',`pb` double DEFAULT NULL COMMENT '市净率',`create_time` varchar(64) NOT NULL COMMENT '写入时间',PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5605 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
步骤解释
获取流执行环境:首先,我们通过StreamExecutionEnvironment.getExecutionEnvironment获取Flink的流执行环境,并设置其运行模式为流处理模式。
创建流表环境:接着,我们通过StreamTableEnvironment.create创建一个流表环境,这个环境允许我们使用SQL语句来操作数据流。
val senv = StreamExecutionEnvironment.getExecutionEnvironment.setRuntimeMode(RuntimeExecutionMode.STREAMING)val tEnv = StreamTableEnvironment.create(senv)
定义Kafka数据源表:我们使用一个SQL语句创建了一个Kafka表re_stock_code_price_kafka,这个表代表了我们要从Kafka读取的数据结构和连接信息。
tEnv.executeSql("CREATE TABLE re_stock_code_price_kafka (" +"`id` BIGINT," +"`code` STRING," +"`name` STRING," +"`close` DOUBLE NULL," +"`change_percent` DOUBLE," +"`change` DOUBLE," +"`volume` DOUBLE," +"`amount` DOUBLE," +"`amplitude` DOUBLE," +"`turnover_rate` DOUBLE," +"`operation` DOUBLE," +"`volume_rate` DOUBLE," +"`high` DOUBLE ," +"`low` DOUBLE," +"`open` DOUBLE," +"`previous_close` DOUBLE," +"`pb` DOUBLE," +"`create_time` STRING," +"rise int"+") WITH (" +"'connector' = 'kafka'," +"'topic' = 'east_money'," +"'properties.bootstrap.servers' = '127.0.0.1:9092'," +"'properties.group.id' = 'mysql2kafka'," +"'scan.startup.mode' = 'earliest-offset'," +"'format' = 'csv'," +"'csv.field-delimiter' = ','" +")")val result = tEnv.executeSql("select * from re_stock_code_price_kafka")
定义MySQL目标表:然后,我们定义了一个MySQL表re_stock_code_price,指定了与MySQL的连接参数和表结构。
val sink_table: String ="""|CREATE TEMPORARY TABLE re_stock_code_price (| id BIGINT NOT NULL,| code STRING NOT NULL,| name STRING NOT NULL,| `close` DOUBLE,| change_percent DOUBLE,| change DOUBLE,| volume DOUBLE,| amount DOUBLE,| amplitude DOUBLE,| turnover_rate DOUBLE,| peration DOUBLE,| volume_rate DOUBLE,| hign DOUBLE,| low DOUBLE,| `open` DOUBLE,| previous_close DOUBLE,| pb DOUBLE,| create_time STRING NOT NULL,| rise int,| PRIMARY KEY (id) NOT ENFORCED|) WITH (| 'connector' = 'jdbc',| 'url' = 'jdbc:mysql://localhost:3306/mydb',| 'driver' = 'com.mysql.cj.jdbc.Driver',| 'table-name' = 're_stock_code_price',| 'username' = 'root',| 'password' = '12345678'|)|""".stripMargintEnv.executeSql(sink_table)
数据转换和写入:最后,我们执行了一个插入操作,将从Kafka读取的数据转换并写入到MySQL中。
tEnv.executeSql("insert into re_stock_code_price select * from re_stock_code_price_kafka")result.print()
全部代码
package org.eastimport org.apache.flink.api.common.RuntimeExecutionMode
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.table.api.bridge.scala.StreamTableEnvironmentobject Kafka2Mysql {def main(args: Array[String]): Unit = {val senv = StreamExecutionEnvironment.getExecutionEnvironment.setRuntimeMode(RuntimeExecutionMode.STREAMING)val tEnv = StreamTableEnvironment.create(senv)tEnv.executeSql("CREATE TABLE re_stock_code_price_kafka (" +"`id` BIGINT," +"`code` STRING," +"`name` STRING," +"`close` DOUBLE NULL," +"`change_percent` DOUBLE," +"`change` DOUBLE," +"`volume` DOUBLE," +"`amount` DOUBLE," +"`amplitude` DOUBLE," +"`turnover_rate` DOUBLE," +"`operation` DOUBLE," +"`volume_rate` DOUBLE," +"`high` DOUBLE ," +"`low` DOUBLE," +"`open` DOUBLE," +"`previous_close` DOUBLE," +"`pb` DOUBLE," +"`create_time` STRING," +"rise int"+") WITH (" +"'connector' = 'kafka'," +"'topic' = 'east_money'," +"'properties.bootstrap.servers' = '127.0.0.1:9092'," +"'properties.group.id' = 'mysql2kafka'," +"'scan.startup.mode' = 'earliest-offset'," +"'format' = 'csv'," +"'csv.field-delimiter' = ','" +")")val result = tEnv.executeSql("select * from re_stock_code_price_kafka")val sink_table: String ="""|CREATE TEMPORARY TABLE re_stock_code_price (| id BIGINT NOT NULL,| code STRING NOT NULL,| name STRING NOT NULL,| `close` DOUBLE,| change_percent DOUBLE,| change DOUBLE,| volume DOUBLE,| amount DOUBLE,| amplitude DOUBLE,| turnover_rate DOUBLE,| peration DOUBLE,| volume_rate DOUBLE,| hign DOUBLE,| low DOUBLE,| `open` DOUBLE,| previous_close DOUBLE,| pb DOUBLE,| create_time STRING NOT NULL,| rise int,| PRIMARY KEY (id) NOT ENFORCED|) WITH (| 'connector' = 'jdbc',| 'url' = 'jdbc:mysql://localhost:3306/mydb',| 'driver' = 'com.mysql.cj.jdbc.Driver',| 'table-name' = 're_stock_code_price',| 'username' = 'root',| 'password' = '12345678'|)|""".stripMargintEnv.executeSql(sink_table)tEnv.executeSql("insert into re_stock_code_price select * from re_stock_code_price_kafka")result.print()print("数据打印完成!!!")}
}
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