1. TCP Source
```
import org.apache.spark.SparkConf
import org.apache.spark.streaming.dstream.ReceiverInputDStream
import org.apache.spark.streaming.{Seconds, StreamingContext}
/
* 需求: 使用netcat工具向9999端口不断的发送数据
* 通过SparkStreaming读取端口数据
*
开启服务-发送数据
* nc -l -p 9999
*
监听服务-消费数据
* nc IP 9999
*
TODO 通过读取 TCP 创建DStream
* API:
* socketTextStream(hostname,port,storageLevel):ReceiverInputDStream[String]