Reading excel files in a streaming fashion in spark 2.0.0

Question

I have a set of Excel format files which needs to be read from Spark(2.0.0) as and when an Excel file is loaded into a local directory. Scala version used here is 2.11.8.

I've tried using readstream method of SparkSession, but I'm not able to read in a streaming way. I'm able to read Excel files statically as:

val df = spark.read.format("com.crealytics.spark.excel").option("sheetName", "Data").option("useHeader", "true").load("Sample.xlsx")

Is there any other way of reading excel files in streaming way from a local directory?

Any answers would be helpful.

Thanks

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Changes done:

val spark = SparkSession.builder().master("local[*]").config("spark.sql.warehouse.dir","file:///D:/pooja").appName("Spark SQL Example").getOrCreate()
spark.conf.set("spark.sql.streaming.schemaInference", true)
import spark.implicits._  
val dataFrame = spark.readStream.format("csv").option("inferSchema",true).option("header", true).load("file:///D:/pooja/sample.csv")
dataFrame.writeStream.format("console").start()
dataFrame.show()

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Updated code:

val spark = SparkSession.builder().master("local[*]").appName("Spark SQL Example").getOrCreate()
spark.conf.set("spark.sql.streaming.schemaInference", true)
import spark.implicits._  
val df = spark.readStream.format("com.crealytics.spark.excel").option("header", true).load("file:///filepath/*.xlsx")
df.writeStream.format("memory").queryName("tab").start().awaitTermination()
val res = spark.sql("select * from tab")
res.show()

Error:

Exception in thread "main" java.lang.UnsupportedOperationException: Data source com.crealytics.spark.excel does not support streamed reading

Can anyone help me resolve this issue.

Answer 1

For a streaming DataFrame you have to provide Schema and currently, DataStreamReader does not support option("inferSchema", true|false). You can set SQLConf setting spark.sql.streaming.schemaInference, which needs to be set at session level.

You can refer here