misc: add Scala example

examples/.scalafmt.conf

@@ -0,0 +1,2 @@
+version = "3.7.3"
+runner.dialect = scala213

examples/README.md

@@ -1,10 +1,52 @@
 ## Delta Sharing examples
-In this folder there are examples taken from the delta.io/delta-sharing quickstart guide and docs. They are available in Python and can be run if the prerequisites are satisfied.  
-The profile file from the open, example Delta Sharing Server is downloaded and located in this folder.
+
+The profile file(open-datasets.share) from the open, example Delta Sharing Server is downloaded and located in this folder.
+
+### Python examples
+In this folder there are examples taken from the delta.io/delta-sharing quickstart guide and docs. They are available in Python and can be run if the prerequisites are satisfied.
+
+
+### Scala example
+In addition, there is a Scala example(`main.scala`). You can easily run the example using [Scala-CLI](https://scala-cli.virtuslab.org/).
+
+```sh
+curl -sSLf https://virtuslab.github.io/scala-cli-packages/scala-setup.sh | sh
+```
+
+```sh
+scala-cli run main.scala
+```
+
+When using Java 9 or later, remove comment-out from the lines(L17~18) as shown below to add java options
+
+```diff
+- ///> using javaOptions "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED"
++ //> using javaOptions "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED"
+- ///> using javaOptions "--add-opens=java.base/sun.security.action=ALL-UNNAMED"
++ //> using javaOptions "--add-opens=java.base/sun.security.action=ALL-UNNAMED"
+```
+to avoid the following exception.
+
+```
+Exception in thread "main" java.lang.IllegalAccessError:
+class org.apache.spark.storage.StorageUtils$ (in unnamed module @0xa803f94)
+cannot access class sun.nio.ch.DirectBuffer
+```
+
+
 
 ### Prerequisites
 * For Python examples, Python3.6+, Delta-Sharing Python Connector, PySpark need to be installed, see [the project docs](https://github.com/delta-io/delta-sharing) for details.
+* For Scala example
+    * [Scala-CLI](https://scala-cli.virtuslab.org/), which downloads Scala compiler and all the dependencies. See the installation guide at the official website → https://scala-cli.virtuslab.org/install
+    * Java 8 or later
 
 ### Instructions
+
+Python
 * To run the example of PySpark in Python run `spark-submit --packages io.delta:delta-sharing-spark_2.12:0.6.2 ./python/quickstart_spark.py`
-* To run the example of pandas DataFrame in Python run `python3 ./python/quickstart_pandas.py`
+* To run the example of pandas DataFrame in Python run `python3 ./python/quickstart_pandas.py`
+
+Scala
+- To run the example of Scala with Spark, run `scala-cli run main.scala`
+- To enable editor support(completion, jump to definition, etc.) for the Scala example, setup [Metals](https://scalameta.org/metals/)(Scala language server) and run `scala-cli setup-ide .`

examples/main.scala

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+//> using scala "2.12.18"
+
+//> using dep "org.apache.spark::spark-core:3.4.0"
+//> using dep "org.apache.spark::spark-sql:3.4.0"
+//> using dep "org.apache.spark::spark-catalyst:3.4.0"
+//> using dep "io.delta::delta-sharing-spark:0.7.0"
+//> using dep "io.delta::delta-core:2.4.0"
+//> using dep "org.json4s::json4s-ast:3.5.3"
+//> using dep "org.codehaus.jackson:jackson-mapper-asl:1.9.13"
+//> using dep "com.fasterxml.jackson.core:jackson-core:2.8.8"
+//> using dep "org.json4s::json4s-core:3.5.3"
+//> using dep "org.json4s::json4s-jackson:3.5.3"
+//> using dep "org.apache.httpcomponents:httpclient:4.5.14"
+
+// When using Java 9+, remove the first slash character from the line 17 and 18
+
+///> using javaOptions "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED",
+///> using javaOptions "--add-opens=java.base/sun.security.action=ALL-UNNAMED"
+
+// hack to violate encapsulation to use DeltaSharingRestClient
+package io.delta.sharing.spark
+
+import org.apache.spark.sql.SparkSession
+import scala.collection.JavaConverters._
+import java.sql.Timestamp
+import java.nio.file.Path
+import org.apache.hadoop.conf.Configuration
+
+object App {
+  def main(args: Array[String]): Unit = {
+    val share = "open-datasets.share"
+    val conf = new Configuration()
+    val provider: DeltaSharingProfileProvider =
+      new io.delta.sharing.spark.DeltaSharingFileProfileProvider(
+        conf,
+        share
+      )
+    val client = new io.delta.sharing.spark.DeltaSharingRestClient(provider)
+    println(client.listAllTables().mkString("\n"))
+
+    val spark = SparkSession
+      .builder()
+      .appName("example")
+      .master("local[*]")
+      .getOrCreate()
+    import spark.implicits._
+    val result = spark.read
+      .format("deltaSharing")
+      .load(
+        share + "/#delta_sharing.default.owid-covid-data"
+      )
+      .where($"iso_code" === "USA")
+      .select(
+        $"iso_code",
+        $"total_cases",
+        $"human_development_index"
+      )
+    result.show(10)
+
+  }
+
+}