2、flink入门程序Wordcount和sql实现

一、DataStream Wordcount

代码地址

基于scala实现

maven依赖如下：

<dependencies>
    <dependency>
        <groupId>org.scala-lang</groupId>
        <artifactId>scala-library</artifactId>
        <version>2.11.8</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.7</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <!-- flink的hadoop兼容 -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-shaded-hadoop2</artifactId>
        <version>1.7.2</version>
    </dependency>
    <!-- flink的hadoop兼容 -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-hadoop-compatibility_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink的scala的api -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-scala_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink streaming的scala的api -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-streaming-scala_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink的java的api -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-java</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink streaming的java的api -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-streaming-java_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink 的kafkaconnector -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-connector-kafka-0.10_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- 使用rocksdb保存flink的state -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-statebackend-rocksdb_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink操作hbase -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-hbase_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink运行时的webUI -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-runtime-web_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- flink table -->
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-table-api-java-bridge_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-table-api-scala-bridge_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-table-planner_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-table-planner-blink_2.11</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <!-- mysql连接驱动 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.35</version>
    </dependency>
</dependencies>

具体代码如下：

import org.apache.flink.api.common.functions.FlatMapFunction
import org.apache.flink.configuration.{ConfigConstants, Configuration}
import org.apache.flink.streaming.api.scala.{DataStream, StreamExecutionEnvironment}
import org.apache.flink.util.Collector

object SocketWordCount {
  def main(args: Array[String]): Unit = {
    val logPath: String = "/tmp/logs/flink_log"

    // 生成配置对象
    var conf: Configuration = new Configuration()
    // 开启flink web UI
    conf.setBoolean(ConfigConstants.LOCAL_START_WEBSERVER, true)
    // 配置web UI的日志文件，否则打印日志到控制台
    conf.setString("web.log.path", logPath)
    // 配置taskManager的日志文件，否则打印到控制台
    conf.setString(ConfigConstants.TASK_MANAGER_LOG_PATH_KEY, logPath)
    // 获取local运行环境
    val env: StreamExecutionEnvironment = StreamExecutionEnvironment.createLocalEnvironmentWithWebUI(conf)
    // 定义socket 源
    val socket: DataStream[String] = env.socketTextStream("localhost", 6666)
    //scala开发需要加一行隐式转换，否则在调用operator的时候会报错
    import org.apache.flink.api.scala._
    // 定义 operators 解析数据，求Wordcount
    val wordCount: DataStream[(String, Int)] = socket.flatMap(_.split(" ")).map((_, 1)).keyBy(_._1).sum(1)
    //使用FlatMapFunction自定义函数来完成flatMap和map的组合功能
    val wordCount2: DataStream[(String, Int)] = socket.flatMap(new FlatMapFunction[String, (String, Int)] {
      override def flatMap(int: String, out: Collector[(String, Int)]): Unit = {
        val strings: Array[String] = int.split(" ")
        for (str <- strings) {
          out.collect((str, 1))
        }
      }
    }).setParallelism(2)
      .keyBy(_._1).sum(1).setParallelism(2)

    // 打印结果
    wordCount.print()

    // 定义任务的名称并运行，operator是惰性的，只有遇到execute才运行
    env.execute("SocketWordCount")
  }
}

二、flink table & sql Wordcount

import org.apache.flink.api.scala.{ExecutionEnvironment, _}
import org.apache.flink.configuration.{ConfigConstants, Configuration}
import org.apache.flink.table.api.Table
import org.apache.flink.table.api.scala.BatchTableEnvironment

import scala.collection.mutable.ArrayBuffer

/**
  * @author xiandongxie
  */
object WordCountSql extends App {
  val logPath: String = "/tmp/logs/flink_log"

  // 生成配置对象
  var conf: Configuration = new Configuration()
  // 开启flink web UI
  conf.setBoolean(ConfigConstants.LOCAL_START_WEBSERVER, true)
  // 配置web UI的日志文件，否则打印日志到控制台
  conf.setString("web.log.path", logPath)
  // 配置taskManager的日志文件，否则打印到控制台
  conf.setString(ConfigConstants.TASK_MANAGER_LOG_PATH_KEY, logPath)
  // 获取local运行环境
  val env: ExecutionEnvironment = ExecutionEnvironment.createLocalEnvironmentWithWebUI(conf)
  //创建一个tableEnvironment
  val tableEnv: BatchTableEnvironment = BatchTableEnvironment.create(env)

  val words: String = "hello flink hello xxd"
  val strings: Array[String] = words.split("\\W+")
  val arrayBuffer = new ArrayBuffer[WordCount]()
  for (f <- strings) {
    arrayBuffer.append(new WordCount(f, 1))
  }

  val dataSet: DataSet[WordCount] = env.fromCollection(arrayBuffer)
  //DataSet 转sql
  val table: Table = tableEnv.fromDataSet(dataSet)
  table.printSchema()
  // 注册为一个表
  tableEnv.createTemporaryView("WordCount", table)
  // 查询
  val selectTable: Table = tableEnv.sqlQuery("select word as word, sum(frequency) as frequency from WordCount GROUP BY word")
  // 查询结果转为dataset，输出
  val value: DataSet[WordCount] = tableEnv.toDataSet[WordCount](selectTable)
  value.print()

}

/**
  * 样例类
  * @param word
  * @param frequency
  */
case class WordCount(word: String, frequency: Long) {
  override def toString: String = {
    word + "\t" + frequency
  }
}

结果：