输入DStreams表示从数据源获取的原始数据流。Spark Streaming拥有两类数据源
（1）基本源（Basic sources）：这些源在StreamingContext API中直接可用。例如文件系统、套接字连接、

Akka的actor等。
（2）高级源（Advanced sources）：这些源包括Kafka,Flume,Kinesis,Twitter等等。

1、基本数据源输入源码

SparkStream 对于外部的数据输入源，一共有下面几种：

（1）用户自定义的数据源：receiverStream

（2）根据TCP协议的数据源： socketTextStream、socketStream

（3）网络数据源：rawSocketStream

（4）hadoop文件系统输入源：fileStream、textFileStream、binaryRecordsStream

（5）其他输入源（队列形式的RDD）：queueStream

/**
   * Create an input stream with any arbitrary user implemented receiver.
   * Find more details at http://spark.apache.org/docs/latest/streaming-custom-receivers.html
   * @param receiver Custom implementation of Receiver
   */
  def receiverStream[T: ClassTag](receiver: Receiver[T]): ReceiverInputDStream[T] = {
    withNamedScope("receiver stream") {
      new PluggableInputDStream[T](this, receiver)
    }
  }

  /**
   * Creates an input stream from TCP source hostname:port. Data is received using
   * a TCP socket and the receive bytes is interpreted as UTF8 encoded `\n` delimited
   * lines.
   * @param hostname      Hostname to connect to for receiving data
   * @param port          Port to connect to for receiving data
   * @param storageLevel  Storage level to use for storing the received objects
   *                      (default: StorageLevel.MEMORY_AND_DISK_SER_2)
   * @see [[socketStream]]
   */
  def socketTextStream(
      hostname: String,
      port: Int,
      storageLevel: StorageLevel = StorageLevel.MEMORY_AND_DISK_SER_2
    ): ReceiverInputDStream[String] = withNamedScope("socket text stream") {
    socketStream[String](hostname, port, SocketReceiver.bytesToLines, storageLevel)
  }

  /**
   * Creates an input stream from TCP source hostname:port. Data is received using
   * a TCP socket and the receive bytes it interpreted as object using the given
   * converter.
   * @param hostname      Hostname to connect to for receiving data
   * @param port          Port to connect to for receiving data
   * @param converter     Function to convert the byte stream to objects
   * @param storageLevel  Storage level to use for storing the received objects
   * @tparam T            Type of the objects received (after converting bytes to objects)
   */
  def socketStream[T: ClassTag](
      hostname: String,
      port: Int,
      converter: (InputStream) => Iterator[T],
      storageLevel: StorageLevel
    )
  : ReceiverInputDStream[T] = {
    new SocketInputDStream[T](this, hostname, port, converter, storageLevel)
  }

  /**
   * Create a input stream from network source hostname:port, where data is received
   * as serialized blocks (serialized using the Spark's serializer) that can be directly
   * pushed into the block manager without deserializing them. This is the most efficient
   * way to receive data.
   * @param hostname      Hostname to connect to for receiving data
   * @param port          Port to connect to for receiving data
   * @param storageLevel  Storage level to use for storing the received objects
   *                      (default: StorageLevel.MEMORY_AND_DISK_SER_2)
   * @tparam T            Type of the objects in the received blocks
   */
  def rawSocketStream[T: ClassTag](
      hostname: String,
      port: Int,
      storageLevel: StorageLevel = StorageLevel.MEMORY_AND_DISK_SER_2
    )
  : ReceiverInputDStream[T] = withNamedScope("raw socket stream") {
    new RawInputDStream[T](this, hostname, port, storageLevel)
  }

  /**
   * Create a input stream that monitors a Hadoop-compatible filesystem
   * for new files and reads them using the given key-value types and input format.
   * Files must be written to the monitored directory by "moving" them from another
   * location within the same file system. File names starting with . are ignored.
   * @param directory HDFS directory to monitor for new file
   * @tparam K Key type for reading HDFS file
   * @tparam V Value type for reading HDFS file
   * @tparam F Input format for reading HDFS file
   */
  def fileStream[
    K: ClassTag,
    V: ClassTag,
    F <: NewInputFormat[K, V]: ClassTag
  ] (directory: String): InputDStream[(K, V)] = {
    new FileInputDStream[K, V, F](this, directory)
  }

  /**
   * Create a input stream that monitors a Hadoop-compatible filesystem
   * for new files and reads them using the given key-value types and input format.
   * Files must be written to the monitored directory by "moving" them from another
   * location within the same file system.
   * @param directory HDFS directory to monitor for new file
   * @param filter Function to filter paths to process
   * @param newFilesOnly Should process only new files and ignore existing files in the directory
   * @tparam K Key type for reading HDFS file
   * @tparam V Value type for reading HDFS file
   * @tparam F Input format for reading HDFS file
   */
  def fileStream[
    K: ClassTag,
    V: ClassTag,
    F <: NewInputFormat[K, V]: ClassTag
  ] (directory: String, filter: Path => Boolean, newFilesOnly: Boolean): InputDStream[(K, V)] = {
    new FileInputDStream[K, V, F](this, directory, filter, newFilesOnly)
  }

  /**
   * Create a input stream that monitors a Hadoop-compatible filesystem
   * for new files and reads them using the given key-value types and input format.
   * Files must be written to the monitored directory by "moving" them from another
   * location within the same file system. File names starting with . are ignored.
   * @param directory HDFS directory to monitor for new file
   * @param filter Function to filter paths to process
   * @param newFilesOnly Should process only new files and ignore existing files in the directory
   * @param conf Hadoop configuration
   * @tparam K Key type for reading HDFS file
   * @tparam V Value type for reading HDFS file
   * @tparam F Input format for reading HDFS file
   */
  def fileStream[
    K: ClassTag,
    V: ClassTag,
    F <: NewInputFormat[K, V]: ClassTag
  ] (directory: String,
     filter: Path => Boolean,
     newFilesOnly: Boolean,
     conf: Configuration): InputDStream[(K, V)] = {
    new FileInputDStream[K, V, F](this, directory, filter, newFilesOnly, Option(conf))
  }

  /**
   * Create a input stream that monitors a Hadoop-compatible filesystem
   * for new files and reads them as text files (using key as LongWritable, value
   * as Text and input format as TextInputFormat). Files must be written to the
   * monitored directory by "moving" them from another location within the same
   * file system. File names starting with . are ignored.
   * @param directory HDFS directory to monitor for new file
   */
  def textFileStream(directory: String): DStream[String] = withNamedScope("text file stream") {
    fileStream[LongWritable, Text, TextInputFormat](directory).map(_._2.toString)
  }

  /**
   * Create an input stream that monitors a Hadoop-compatible filesystem
   * for new files and reads them as flat binary files, assuming a fixed length per record,
   * generating one byte array per record. Files must be written to the monitored directory
   * by "moving" them from another location within the same file system. File names
   * starting with . are ignored.
   *
   * '''Note:''' We ensure that the byte array for each record in the
   * resulting RDDs of the DStream has the provided record length.
   *
   * @param directory HDFS directory to monitor for new file
   * @param recordLength length of each record in bytes
   */
  def binaryRecordsStream(
      directory: String,
      recordLength: Int): DStream[Array[Byte]] = withNamedScope("binary records stream") {
    val conf = _sc.hadoopConfiguration
    conf.setInt(FixedLengthBinaryInputFormat.RECORD_LENGTH_PROPERTY, recordLength)
    val br = fileStream[LongWritable, BytesWritable, FixedLengthBinaryInputFormat](
      directory, FileInputDStream.defaultFilter: Path => Boolean, newFilesOnly = true, conf)
    val data = br.map { case (k, v) =>
      val bytes = v.getBytes
      require(bytes.length == recordLength, "Byte array does not have correct length. " +
        s"${bytes.length} did not equal recordLength: $recordLength")
      bytes
    }
    data
  }

  /**
   * Create an input stream from a queue of RDDs. In each batch,
   * it will process either one or all of the RDDs returned by the queue.
   *
   * NOTE: Arbitrary RDDs can be added to `queueStream`, there is no way to recover data of
   * those RDDs, so `queueStream` doesn't support checkpointing.
   *
   * @param queue      Queue of RDDs. Modifications to this data structure must be synchronized.
   * @param oneAtATime Whether only one RDD should be consumed from the queue in every interval
   * @tparam T         Type of objects in the RDD
   */
  def queueStream[T: ClassTag](
      queue: Queue[RDD[T]],
      oneAtATime: Boolean = true
    ): InputDStream[T] = {
    queueStream(queue, oneAtATime, sc.makeRDD(Seq[T](), 1))
  }

  /**
   * Create an input stream from a queue of RDDs. In each batch,
   * it will process either one or all of the RDDs returned by the queue.
   *
   * NOTE: Arbitrary RDDs can be added to `queueStream`, there is no way to recover data of
   * those RDDs, so `queueStream` doesn't support checkpointing.
   *
   * @param queue      Queue of RDDs. Modifications to this data structure must be synchronized.
   * @param oneAtATime Whether only one RDD should be consumed from the queue in every interval
   * @param defaultRDD Default RDD is returned by the DStream when the queue is empty.
   *                   Set as null if no RDD should be returned when empty
   * @tparam T         Type of objects in the RDD
   */
  def queueStream[T: ClassTag](
      queue: Queue[RDD[T]],
      oneAtATime: Boolean,
      defaultRDD: RDD[T]
    ): InputDStream[T] = {
    new QueueInputDStream(this, queue, oneAtATime, defaultRDD)
  }

第二步：对上面文件进行 jar文件的打包，并放入到集群目录中

启动程序如下：

java -cp DataSimulation.jar streamingSimulation /root/application/upload/Information 9999 1000

其中DataSimulation.jar是你打包的jar文件名字，streamingSimulation是你這个jar文件的main函数，

root/application/upload/Information 是数据文件 information 的位置，information内部数据如下：

9999是端口号

1000（ms）是发送数据间隔时间

第三步，编写自己的receiver函数和SparkStreaming程序，程序如下：

import java.io.{BufferedReader, InputStreamReader}
import java.net.Socket
import java.nio.charset.StandardCharsets

import org.apache.spark.{Logging, SparkConf}
import org.apache.spark.storage.StorageLevel
import org.apache.spark.streaming.{Seconds, StreamingContext}
import org.apache.spark.streaming.receiver.Receiver

/**
  * Custom Receiver that receives data over a socket. Received bytes are interpreted as
  * text and \n delimited lines are considered as records. They are then counted and printed.
  *
  * To run this on your local machine, you need to first run a Netcat server
  *    `$ nc -lk 9999`
  * and then run the example
  *    `$ bin/run-example org.apache.spark.examples.streaming.CustomReceiver localhost 9999`
  */
object CustomReceiver {
  def main(args: Array[String]) {
    if (args.length < 2) {
      System.err.println("Usage: CustomReceiver <hostname> <port>")
      System.exit(1)
    }



    // Create the context with a 1 second batch size
    val sparkConf = new SparkConf().setAppName("CustomReceiver").setMaster("local[4]")
    val ssc = new StreamingContext(sparkConf, Seconds(1))

    // Create an input stream with the custom receiver on target ip:port and count the
    // words in input stream of \n delimited text (eg. generated by 'nc')
    val lines = ssc.receiverStream(new CustomReceiver(args(0), args(1).toInt))
    val words = lines.flatMap(_.split(" "))
    val wordCounts = words.map(x => (x, 1)).reduceByKey(_ + _)
    wordCounts.print()
    ssc.start()
    ssc.awaitTermination()
  }
}


class CustomReceiver(host: String, port: Int)
  extends Receiver[String](StorageLevel.MEMORY_AND_DISK_2) with Logging {

  def onStart() {
    // Start the thread that receives data over a connection
    new Thread("Socket Receiver") {
      override def run() { receive() }
    }.start()
  }

  def onStop() {
    // There is nothing much to do as the thread calling receive()
    // is designed to stop by itself isStopped() returns false
  }

  /** Create a socket connection and receive data until receiver is stopped */
  private def receive() {
    var socket: Socket = null
    var userInput: String = null
    try {
      logInfo("Connecting to " + host + ":" + port)
      socket = new Socket(host, port)
      logInfo("Connected to " + host + ":" + port)
      val reader = new BufferedReader(
        new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8))
      userInput = reader.readLine()
      while(!isStopped && userInput != null) {
        store(userInput)
        userInput = reader.readLine()
      }
      reader.close()
      socket.close()
      logInfo("Stopped receiving")
      restart("Trying to connect again")
    } catch {
      case e: java.net.ConnectException =>
        restart("Error connecting to " + host + ":" + port, e)
      case t: Throwable =>
        restart("Error receiving data", t)
    }
  }
}

第四步、配置完运行CustomReceiver的函数

第五步、运行程序

2.2  根据TCP协议的数据源实验

(1)socketTextStream函数
第一步：数据模拟，参考前面

第二步：编写SparkStreaming程序，程序如下：

import org.apache.log4j.{Level, Logger}
import org.apache.spark.streaming.{Seconds, StreamingContext}
import org.apache.spark.{SparkConf, SparkContext}

/**
  * Created by legotime on 6/1/16.
  */
object TCPOnStreaming {
  def main(args: Array[String]) {

    Logger.getLogger("org.apache.spark").setLevel(Level.ERROR)
    Logger.getLogger("org.eclipse.jetty.Server").setLevel(Level.OFF)

    val conf = new SparkConf().setAppName("TCPOnStreaming example").setMaster("local[4]")
    val sc = new SparkContext(conf)
    val ssc = new StreamingContext(sc,Seconds(2))


    //set the Checkpoint directory
    ssc.checkpoint("/Res")

    //get the socket Streaming data
    val socketStreaming = ssc.socketTextStream("master",9999)

    val data = socketStreaming.map(x =>(x,1))
    data.print()

    ssc.start()
    ssc.awaitTermination()
  }

}

第三步，运行程序，结果如下：

(2)socketStream函数

第一步：数据模拟，参考前面

第二步：编写SparkStreaming程序，程序如下：

import java.io.{InputStream}


import org.apache.log4j.{Level, Logger}
import org.apache.spark.storage.StorageLevel
import org.apache.spark.streaming.{Seconds, StreamingContext}
import org.apache.spark.{SparkConf, SparkContext}


/**
  * Created by legotime on 6/1/16.
  */


object socketStreamData {
  def main(args: Array[String]) {

    Logger.getLogger("org.apache.spark").setLevel(Level.ERROR)
    Logger.getLogger("org.eclipse.jetty.Server").setLevel(Level.OFF)

    val conf = new SparkConf().setAppName("<span style="font-family: 宋体;">socketStreamData</span>").setMaster("local[4]")
    val sc = new SparkContext(conf)
    val ssc = new StreamingContext(sc,Seconds(2))


    //set the Checkpoint directory
    ssc.checkpoint("/Res")



    val SocketData = ssc.socketStream[String]("master",9999,myDeserialize,StorageLevel.MEMORY_AND_DISK_SER )



    //val data = SocketData.map(x =>(x,1))
    //data.print()
    SocketData.print()

    ssc.start()
    ssc.awaitTermination()
  }

  def myDeserialize(data:InputStream): Iterator[String]={
    data.read().toString.map( x => x.hashCode().toString).iterator
  }

}

2.3  网络数据源：rawSocketStream

import org.apache.spark.SparkConf
import org.apache.spark.storage.StorageLevel
import org.apache.spark.streaming._
import org.apache.spark.util.IntParam

/**
 * Receives text from multiple rawNetworkStreams and counts how many '\n' delimited
 * lines have the word 'the' in them. This is useful for benchmarking purposes. This
 * will only work with spark.streaming.util.RawTextSender running on all worker nodes
 * and with Spark using Kryo serialization (set Java property "spark.serializer" to
 * "org.apache.spark.serializer.KryoSerializer").
 * Usage: RawNetworkGrep <numStreams> <host> <port> <batchMillis>
 *   <numStream> is the number rawNetworkStreams, which should be same as number
 *               of work nodes in the cluster
 *   <host> is "localhost".
 *   <port> is the port on which RawTextSender is running in the worker nodes.
 *   <batchMillise> is the Spark Streaming batch duration in milliseconds.
 */
object RawNetworkGrep {
  def main(args: Array[String]) {
    if (args.length != 4) {
      System.err.println("Usage: RawNetworkGrep <numStreams> <host> <port> <batchMillis>")
      System.exit(1)
    }

    StreamingExamples.setStreamingLogLevels()

    val Array(IntParam(numStreams), host, IntParam(port), IntParam(batchMillis)) = args
    val sparkConf = new SparkConf().setAppName("RawNetworkGrep")
    // Create the context
    val ssc = new StreamingContext(sparkConf, Duration(batchMillis))

    val rawStreams = (1 to numStreams).map(_ =>
      ssc.rawSocketStream[String](host, port, StorageLevel.MEMORY_ONLY_SER_2)).toArray
    val union = ssc.union(rawStreams)
    union.filter(_.contains("the")).count().foreachRDD(r =>
      println("Grep count: " + r.collect().mkString))
    ssc.start()
    ssc.awaitTermination()
  }
}

2.4  hadoop文件系统输入源：fileStream、textFileStream、binaryRecordsStream
(1)fileStream函数

(2)textFileStream函数

第一步、写好SparkStreaming程序，并启动

import org.apache.log4j.{Level, Logger}
import org.apache.spark.streaming.{Seconds, StreamingContext}
import org.apache.spark.{SparkConf, SparkContext}


object fileStreamData {
  def main(args: Array[String]) {
    Logger.getLogger("org.apache.spark").setLevel(Level.ERROR)
    Logger.getLogger("org.eclipse.jetty.Server").setLevel(Level.OFF)



    val conf = new SparkConf().setAppName("fileStreamData").setMaster("local[2]")
    val sc =new SparkContext(conf)
    val ssc = new StreamingContext(sc, Seconds(2))

	//fileStream 用法
	//val lines = ssc.fileStream[LongWritable, Text, TextInputFormat]("hdfs:///examples/").map{ case (x, y) => (x.toString, y.toString) }
    //val lines = ssc.fileStream[LongWritable, Text, TextInputFormat]("/root/application/dataDir/").map{ case (x, y) => (x.toString, y.toString) }
    //lines.print()
    val lines = ssc.textFileStream("/root/application/dataDir/")
    val wordCount = lines.flatMap(_.split(" ")).map(x => (x,1)).reduceByKey(_+_)
    wordCount.print()

    ssc.start()
    ssc.awaitTermination()

  }
}

第二步，在textFileStream指定目录输入文件

第三步、查看结果

2.5  其他输入源（队列形式的RDD）：queueStream

直接运行下面程序

import scala.collection.mutable.Queue

import org.apache.spark.SparkConf
import org.apache.spark.rdd.RDD
import org.apache.spark.streaming.{Seconds, StreamingContext}



object QueueStream {
  def main(args: Array[String]) {

    val sparkConf = new SparkConf().setAppName("QueueStream").setMaster("local[4]")
    // Create the context
    val ssc = new StreamingContext(sparkConf, Seconds(1))

    // Create the queue through which RDDs can be pushed to
    // a QueueInputDStream
    val rddQueue = new Queue[RDD[Int]]()

    // Create the QueueInputDStream and use it do some processing
    val inputStream = ssc.queueStream(rddQueue)
    val mappedStream = inputStream.map(x => (x % 10, 1))
    val reducedStream = mappedStream.reduceByKey(_ + _)
    reducedStream.print()
    ssc.start()

    // Create and push some RDDs into rddQueue
    for (i <- 1 to 30) {
      rddQueue.synchronized {
        rddQueue += ssc.sparkContext.makeRDD(1 to 1000, 10)
      }
      Thread.sleep(1000)
    }
    ssc.stop()
  }

}

结果