Section 1: Set up your development environment

Select your preferred language (Java/Scala) above.

To follow tutorial steps you will need a code editor, a build tool, and grpcurl (a CLI for sending gRPC calls). You can use your preferred code editor. We provide the steps for using IntelliJ IDEA new tab from JetBrains. For the Java version of the example, we use Apache Maven as the build tool.

This tutorial uses a PostgreSQL database and Kafka. You may run local installations during development, but we recommend running both services using Docker new tab. The template project’s root directory includes a Docker Compose new tab file that you can use to run PostgreSQL and Kafka. The provided Docker Compose file also runs Zookeeper which is required to run a Kafka broker.

The following sections provide links for downloading and installing:

We also provide Downloadable example source of the different phases of completion.

The Java example takes advantage of some of the Java features introduced in Java 21 such as records and advanced pattern matching. If you can’t have Java 21 installed, you can still follow the tutorial, but you will need to adjust some code accordingly to the Java version in use.

IntelliJ IDEA

Java

Download and install IntelliJ new tab.

Scala

To install IntelliJ and prepare to develop the Scala example, follow these steps:

  1. Download and install IntelliJ new tab.

  2. From the Preferences menu, add the Scala plugin.

Build tool

Java

For the Java Shopping Cart example, we use Maven as the build tool. Install Maven if you haven’t already.

Scala

For the Scala Shopping Cart example, we use sbt as the build tool. Install sbt if you haven’t already.

sbt is an interactive shell. If you start it with the sbt command, you can repeatedly run tasks like compile and test in the sbt shell. In the tutorial we use the full command for clarity, such as sbt compile. You can run tasks independently in this way, but it’s faster to leave the sbt shell running and only enter the tasks. For example:

$ sbt
...
sbt:shopping-cart-service> compile
...
sbt:shopping-cart-service> test
...

The grpcurl tool

The grpcurl new tab tool is useful for making gRPC calls from the command line. It is used in tutorial procedures and we recommend that you install it as described in the grpcurl documentation new tab.

Docker and Docker Compose

See the instructions for installing Docker new tab and Docker Compose new tab on your platform.

Downloadable example source

We encourage you to enter the example code, even if by copying and pasting. If you get stuck or prefer to skip some main steps, we provide source files for download. The introduction of each page with tutorial development steps includes links to two zip files: one with completed source up to that point, and one with completed source for the steps described on that page.

In next step you will find instructions of how to download the starting template for the tutorial.

Java

If you would like to run the full example, you can download the full Java sources. In this case, we suggest you scan the tutorial instructions to identify the source files that you can learn from.

Scala

If you would like to run the full example, you can download the full Scala sources. In this case, we suggest you scan the tutorial instructions to identify the source files that you can learn from.