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Scala and Java Examples

Scala and Java Examples contains template projects for RDD, SQL and Viz. The template projects have been configured properly.

Note that, although the template projects are written in Scala, the same APIs can be used in Java as well.

Folder structure

The folder structure of this repository is as follows.

  • rdd-colocation-mining: a scala template shows how to use Sedona RDD API in Spatial Data Mining
  • sql: a scala template shows how to use Sedona DataFrame and SQL API
  • viz: a scala template shows how to use Sedona Viz RDD and SQL API

Compile and package

Prerequisites

Please make sure you have the following software installed on your local machine:

  • For Scala: Scala 2.12, SBT
  • For Java: JDK 1.8, Apache Maven 3

Compile

Run a terminal command sbt assembly within the folder of each template

Submit your fat jar to Spark

After running the command mentioned above, you are able to see a fat jar in ./target folder. Please take it and use ./bin/spark-submit to submit this jar.

To run the jar in this way, you need to:

  • Either change Spark Master Address in template projects or simply delete it. Currently, they are hard coded to local[*] which means run locally with all cores.

  • Change the dependency packaging scope of Apache Spark from "compile" to "provided". This is a common packaging strategy in Maven and SBT which means do not package Spark into your fat jar. Otherwise, this may lead to a huge jar and version conflicts!

  • Make sure the dependency versions in build.sbt are consistent with your Spark version.

Run template projects locally

We highly suggest you use IDEs to run template projects on your local machine. For Scala, we recommend IntelliJ IDEA with Scala plug-in. For Java, we recommend IntelliJ IDEA and Eclipse. With the help of IDEs, you don't have to prepare anything (even don't need to download and set up Spark!). As long as you have Scala and Java, everything works properly!

Scala

Import the Scala template project as SBT project. Then run the Main file in this project.


Last update: May 18, 2021 19:30:39
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