spark streaming的入门案例

青旅半醒 2022-04-18 05:18 155阅读 0赞

# 1， spark streaming： tcp 源 #

maven依赖：

<dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-streaming_2.11</artifactId>
        <version>2.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-streaming-kafka-0-10_2.11</artifactId>
        <version>2.1.0</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-core_2.11</artifactId>
        <version>2.1.0</version>
    </dependency>

程序：

import org.apache.spark.SparkConf
    import org.apache.spark.streaming.{Seconds, StreamingContext}
    
    object wc {
      def main(args: Array[String]): Unit = {
        //配置：spark
        val conf = new SparkConf().setMaster("local[3]").setAppName("wc")
        //流的上下文
        val ssc = new StreamingContext(conf,Seconds(2))
        //获取输入源
        val dstream1 = ssc.socketTextStream("localhost",9999)
        val dstream2 = dstream1.map((_, 1)).reduceByKey(_+_)
        
        //开启上下文
        dstream2.print()
        ssc.start()
        ssc.awaitTermination()
      }
    }

# 2， spark streaming ： kafka数据源 #

1.5.2版本

<dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-core_2.10</artifactId>
       <version>1.5.2</version>
    </dependency>
    <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-streaming_2.10</artifactId>
       <version>1.5.2</version>
    </dependency>
    <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-streaming-kafka_2.10</artifactId>
       <version>1.5.2</version>
    </dependency>
    
    object wc_kafka {
    
    	def  updateFunc ()  = (iterator: Iterator[(String, Seq[Int], Option[Int])]) => {
    	 iterator.flatMap {
    	   case (x, y, z) =>
    		 Some(y.sum + z.getOrElse(0)).map(n => (x, n))
    	 }
    	}
    	
      def main(args: Array[String]): Unit = {
      
    	//创建SparkConf并设置AppName
    	val Array(zkQuorum, groupId, topics, numThreads, hdfs) = Array(
    	 "localhost:2181", "g1", "t1,topoic1", "1", "check-point2")
    	val conf = new SparkConf().setAppName("UrlCount").setMaster("local[3]")
    	
    	//创建StreamingContext
    	val ssc = new StreamingContext(conf, Seconds(2))
    	ssc.checkpoint(hdfs)//设置检查点
    	
    	//从Kafka中拉取数据
    	val topicMap = topics.split(",").map((_, numThreads.toInt)).toMap //设置topic信息
    	val lines = KafkaUtils.createStream(ssc, zkQuorum, groupId, topicMap, StorageLevel.MEMORY_AND_DISK).map(_._2)
    	val wc = lines.flatMap(_.split(" ")).map((_, 1))
    	val result = wc.updateStateByKey(updateFunc _, new HashPartitioner(ssc.sparkContext.defaultParallelism), true)
    	
    	// 将结果打印到控制台
    	result.print()
    	ssc.start()
    	ssc.awaitTermination()}
      }
    }

2.1.0版本

<dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-core_2.11</artifactId>
       <version>2.1.0</version>
    </dependency>
    <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-streaming_2.11</artifactId>
       <version>2.1.0</version>
    </dependency>
    <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-streaming-kafka-0-10_2.11</artifactId>
       <version>2.1.0</version>
    </dependency>
    
     //代码      
    import org.apache.kafka.common.serialization.StringDeserializer
    import org.apache.spark._
    import org.apache.spark.streaming._
    import org.apache.spark.streaming.kafka010.{ConsumerStrategies, LocationStrategies, KafkaUtils}
    
    object wc_kafka {
      def main(args: Array[String]): Unit = {
        val conf = new SparkConf()
        conf.setAppName("kafka")
        conf.setMaster("local[*]")
    
        val ssc = new StreamingContext(conf, Seconds(2))
    
        //kafka参数
        val kafkaParams = Map[String, Object](
          "bootstrap.servers" -> "localhost:9092",
          "key.deserializer" -> classOf[StringDeserializer],
          "value.deserializer" -> classOf[StringDeserializer],
          "group.id" -> "g1",
          "auto.offset.reset" -> "latest",
          "enable.auto.commit" -> (false: java.lang.Boolean)
        )
        //创建streaming输入源
        val topics = Array("t1")
        val stream = KafkaUtils.createDirectStream[String, String](
          ssc,
          LocationStrategies.PreferConsistent,
          ConsumerStrategies.Subscribe[String, String](topics, kafkaParams)
        )
    
        //打印结果
        val ds2 = stream.map(record => (record.key, record.value))
        ds2.print()
    
        //启动
        ssc.start()
        ssc.awaitTermination()
      }
    }