运行Spark Structured Streaming Programming Guide遇到Connection refused

运行Spark Structured Streaming Programming Guide遇到Connection refused

http://spark.apache.org/docs/2.4.0/structured-streaming-programming-guide.html

官方文档使用netcat的指令不能直接运行，提示没有-k选项。

$ nc -lk 9999
netcat: invalid option -- 'k'
Try `netcat --help' for more information.

需要改成

$ nc -l -p 9999
apache hadoop
apache spark

再在另一个终端的spark目录运行如下命令即可

$ ./bin/run-example org.apache.spark.examples.sql.streaming.StructuredNetworkWordCount localhost 9999