Add missing class for DataLake example :)

Author: GezimSejdiu

sansa-examples-spark/src/main/scala/net/sansa_stack/examples/spark/query/DataLake.scala

@@ -0,0 +1,66 @@
+package net.sansa_stack.examples.spark.query
+
+import scala.collection.mutable
+
+import net.sansa_stack.query.spark.query._
+import org.apache.jena.riot.Lang
+import org.apache.spark.sql.SparkSession
+
+/**
+ * Run SPARQL queries over Spark using Data Lake approach.
+ */
+object DataLake {
+
+  def main(args: Array[String]) {
+    parser.parse(args, Config()) match {
+      case Some(config) =>
+        run(config.queryFile, config.mappingsFile, config.configFile)
+      case None =>
+        println(parser.usage)
+    }
+  }
+
+  def run(queryFile: String, mappingsFile: String, configFile: String): Unit = {
+
+    println("======================================")
+    println("|   Sparqlify example                |")
+    println("======================================")
+
+    val spark = SparkSession.builder
+      .appName(s"DataLake (CSV) example")
+      .master("local[*]")
+      .getOrCreate()
+
+    val result = spark.sparqlDL(queryFile, mappingsFile, configFile)
+    result.show()
+
+    spark.stop
+
+  }
+
+  case class Config(
+    queryFile: String = getClass.getResource("/datalake/queries/Q1.sparql").getPath,
+    mappingsFile: String = getClass.getResource("/datalake/config_csv-only").getPath,
+    configFile: String = getClass.getResource("/datalake/mappings_csv-only.ttl").getPath)
+
+  val parser = new scopt.OptionParser[Config]("Sparqlify example") {
+
+    head(" DataLake (CSV) example")
+
+    opt[String]('f', "queryFile").valueName("<queryFile>").
+      action((x, c) => c.copy(queryFile = x)).
+      text("a file containing SPARQL queries or a single query, default: /queries/Q1.sparql")
+
+    opt[String]('m', "mappingsFile").valueName("<mappingsFile>").
+      action((x, c) => c.copy(mappingsFile = x)).
+      text("the mappings to the target sources, default: /config_csv-only")
+
+    opt[String]('c', "configFile").optional().valueName("<configFile>").
+      action((x, c) => c.copy(configFile = x)).
+      text("configuration file for different data sources, default: /mappings_csv-only.ttl")
+
+    help("help").text("prints this usage text")
+  }
+
+}
+