flink Datastreamkaifa之自定义Source(Custom-source)

程序员文章站 2022-06-16 12:05:11

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进入官网我们可以看到很多内置的source/sink,这能覆盖大多数的应用场景,
嗯,大多数…
flink Datastreamkaifa之自定义Source(Custom-source)

产品:
flink Datastreamkaifa之自定义Source(Custom-source)
我:

产品:“我想直接读取mysql的数据…”
我:
flink Datastreamkaifa之自定义Source(Custom-source)
那就自定义一个吧,首先学习一下如何自定义Datasource,显然官方预见到了这个场景,给我们提供了三个接口:

SourceFunction:非并行数据源
ParallelSourceFunction:并行数据源
RichParallelSourceFunction:(Rich??,这个我懂,丰富的意思,英语四级300多分不是白考的)丰富的并行数据源
下面一个一个举栗子:

SourceFunction:并行数据源

定义MyNoParallelSourceScala 类

package hctang.tech.streaming.custormSource

import org.apache.flink.streaming.api.functions.source.SourceFunction
import org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext

/**
  * 自定义并行度为一的source
  * 实现从一开始产生递增
  */

class MyNoParallelSourceScala extends SourceFunction[Long]{
  /* override def run(ctx:SourceContext[Long])={

  }*/
  var count=1L
  var isRunning=true
  override def run(sourceContext: SourceContext[Long]): Unit = {
    while(isRunning){
      sourceContext.collect(count)
      count+=1
      Thread.sleep(1000)
    }

  }


  override def cancel(): Unit = {
    isRunning=false


  }

}

调用

package hctang.tech.streaming.custormSource

import org.apache.flink.api.common.typeinfo.TypeInformation
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.api.windowing.time.Time

object StreamingDemoWithNoParallelSourceScala {
  def main(args: Array[String]): Unit = {
    implicit val typeInfo = TypeInformation.of(classOf[(String)])
    //获取执行环境
    val env=StreamExecutionEnvironment.getExecutionEnvironment
    //隐式转换
    import org.apache.flink.api.scala._
    val text=env.addSource(new MyNoParallelSourceScala)
    val mapData = text.map(line=>{
      println("接收到的数据："+line)
      line
    })
    val sum =mapData.timeWindowAll(Time.seconds(5)).sum(0)//窗口,五秒一次
    sum.print().setParallelism(1)
    env.execute("StreamingFromCollectionScala")


  }

}

执行结果如图:
flink Datastreamkaifa之自定义Source(Custom-source)

定义并行数据源

定义MyParallelSourceScala

package hctang.tech.streaming.custormSource

import org.apache.flink.streaming.api.functions.source.{ParallelSourceFunction, SourceFunction}
import org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext

/**
  * 自定义并行度为一的source
  * 实现从一开始产生递增
  */

class MyParallelSourceScala extends ParallelSourceFunction[Long]{
  /* override def run(ctx:SourceContext[Long])={

  }*/
  var count=1L
  var isRunning=true
  override def run(sourceContext: SourceContext[Long]): Unit = {
    while(isRunning){
      sourceContext.collect(count)
      count+=1
      Thread.sleep(1000)
    }

  }


  override def cancel(): Unit = {
    isRunning=false


  }

}

定义StreamingDemoWithParallelSourceScala调用MyParallelSourceScala

package hctang.tech.streaming.custormSource

import org.apache.flink.api.common.typeinfo.TypeInformation
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.api.windowing.time.Time

object StreamingDemoWithParallelSourceScala {
  def main(args: Array[String]): Unit = {
    implicit val typeInfo = TypeInformation.of(classOf[(String)])
    //获取执行环境
    val env=StreamExecutionEnvironment.getExecutionEnvironment
    //隐式转换
    import org.apache.flink.api.scala._
    val text=env.addSource(new MyParallelSourceScala).setParallelism(2)
    val mapData = text.map(line=>{
      println("接收到的数据："+line)
      line
    })
    val sum =mapData.timeWindowAll(Time.seconds(5)).sum(0)
    sum.print().setParallelism(1)
    env.execute("StreamingFromCollectionScala")


  }

}

运行结果

定义丰富的并行数据源…

定义MyRichParallelSourceScala

package hctang.tech.streaming.custormSource

import org.apache.flink.configuration.Configuration
import org.apache.flink.streaming.api.functions.source.{ParallelSourceFunction, RichParallelSourceFunction}
import org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext

/**
  * 自定义并行度为一的source
  * 实现从一开始产生递增
  */

class MyRichParallelSourceScala extends RichParallelSourceFunction[Long]{
  /* override def run(ctx:SourceContext[Long])={

  }*/
  var count=1L
  var isRunning=true
  override def run(sourceContext: SourceContext[Long]): Unit = {
    while(isRunning){
      sourceContext.collect(count)
      count+=1
      Thread.sleep(1000)
    }

  }


  override def cancel(): Unit = {
    isRunning=false


  }
//Rich
  override def open(parameters: Configuration): Unit = super.open(parameters)

  override def close(): Unit = super.close()

}

说明: 看上面代码,是不是多了open和close方法,没错,Rich!!

调用

package hctang.tech.streaming.custormSource

import org.apache.flink.api.common.typeinfo.TypeInformation
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.api.windowing.time.Time

object StreamingDemoWithRichParallelSourceScala {
  def main(args: Array[String]): Unit = {
    implicit val typeInfo = TypeInformation.of(classOf[(String)])
    //获取执行环境
    val env=StreamExecutionEnvironment.getExecutionEnvironment
    //隐式转换
    import org.apache.flink.api.scala._
    val text=env.addSource(new MyRichParallelSourceScala).setParallelism(100)
    val mapData = text.map(line=>{
      println("接收到的数据："+line)
      line
    })
    val sum =mapData.timeWindowAll(Time.seconds(10)).sum(0)
    sum.print().setParallelism(1)
    env.execute("StreamingFromCollectionScala")



  }

}

运行结果

恩…错了,重来,刚并行度设置成了100

flink Datastreamkaifa之自定义Source(Custom-source)
并行度改为2

热身结束,回到最开始的场景,读取mysql中的数据,mysql有url,需要打开,不用了需要关闭,显然我们需要用RichSourceFunction(里边有close和open方法),

class类SQL_source

package hctang.tech.streaming.custormSource
import java.sql.{Connection, DriverManager, PreparedStatement}

import org.apache.flink.configuration.Configuration
import org.apache.flink.streaming.api.functions.source.RichSourceFunction
import org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext
class SQL_source extends RichSourceFunction[Student]{
  private var connection: Connection = null

  private var ps: PreparedStatement = null

  override def open(parameters: Configuration): Unit = {
    val driver = "com.mysql.jdbc.Driver"
    val url = "jdbc:mysql://local:3306/test"
    val username = "root"

    val password = "root"
    Class.forName(driver)
    connection = DriverManager.getConnection(url, username, password)
    val sql = "select id , name , addr , sex from student"
    ps = connection.prepareStatement(sql)
  }

  override def close(): Unit = {
    if (connection != null) {
      connection.close()
    }
    if (ps != null) {
      ps.close()
    }

  }

  override def run(sourceContext: SourceContext[Student]): Unit = {
    val queryRequest = ps.executeQuery()

    while (queryRequest.next()) {

      val stuid = queryRequest.getInt("id")

      val stuname = queryRequest.getString("name")
      val stuaddr = queryRequest.getString("addr")
      val stusex = queryRequest.getString("sex")

      val stu = new Student(stuid, stuname, stuaddr, stusex)
      sourceContext.collect(stu)

    }

  }

  override def cancel(): Unit = {}

}

case class Student(stuid: Int, stuname: String, stuaddr: String, stusex: String) {
  override def toString: String = {

    "stuid:" + stuid + "	stuname:" + stuname + "	stuaddr:" + stuaddr + "	stusex:" + stusex

  }

}

Object:MysqlSourceScala

package hctang.tech.streaming.custormSource

import org.apache.flink.streaming.api.scala.{DataStream, StreamExecutionEnvironment}
import org.apache.flink.api.scala._
object MysqlSoureScala {
  def main(args:Array[String]):Unit = {

    val env = StreamExecutionEnvironment.getExecutionEnvironment
    val source: DataStream[Student] = env.addSource(new SQL_source)
    source.print()

    env.execute()

  }


}

注意,不要忘记添加依赖(根据自己环境修改)

pom.xml

<?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.hctang.flink</groupId>
    <artifactId>firstcode</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>


    <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-scala -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-java</artifactId>
            <version>1.9.0</version>



            <!--<scope>provided</scope>-->

        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-java_2.11</artifactId>
            <version>1.9.0</version>
            <!--<scope>provided</scope>-->
            <!--指定包的作用域，集群中运行的话，很多东西并不需要，-->

         </dependency>

    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-scala_2.11</artifactId>
        <version>1.9.0</version>


    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-streaming-scala -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-streaming-scala_2.11</artifactId>
        <version>1.9.0</version>
    </dependency><!--flink kafka connector-->
        <dependency>
	<groupId>org.apache.flink</groupId>
	<artifactId>flink-connector-kafka-0.11_2.11</artifactId>
	<version>1.9.0</version>
</dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-shaded-hadoop-2 -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-shaded-hadoop-2</artifactId>
            <version>2.7.5-9.0</version>
        </dependency>
        <dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-hadoop-fs</artifactId>
    <version>1.9.0</version>
</dependency>

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-common</artifactId>
    <version>2.7.3</version>
</dependency>

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-hdfs</artifactId>
    <version>2.7.3</version>
</dependency>

        <!--日志-->
<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>
        <!--alibaba fastjson-->
        <dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>fastjson</artifactId>
	<version>1.2.51</version>
</dependency>
<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.46</version>
</dependency>



    </dependencies>


<build>
        <plugins>
            <!-- 编译插件 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <!-- scala编译插件 -->
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.1.6</version>
                <configuration>
                    <scalaCompatVersion>2.11</scalaCompatVersion>
                    <scalaVersion>2.11.8</scalaVersion>
                    <encoding>UTF-8</encoding>
                </configuration>
                <executions>
                    <execution>
                        <id>compile-scala</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>add-source</goal>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>test-compile-scala</id>
                        <phase>test-compile</phase>
                        <goals>
                            <goal>add-source</goal>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <!-- 打jar包插件(会包含所有依赖) -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <!-- 可以设置jar包的入口类(可选)-->
                            <mainClass>hctang.tech.bacth.Bacth.BatchWordCount</mainClass>

                       </manifest>
                    </archive>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>



</project>

flink Datastreamkaifa之自定义Source(Custom-source)

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