CorDapp Standard Development Environment (CSDE)

The CorDapp Standard Development Environment (CSDE) makes the process of prototyping CorDapps on Developer Preview 2 more straight-forward. The CSDE is obtained by cloning our CSDE-Cordapp-Template-Kotlin repository to your local machine. The CSDE provides:

• A prepared CorDapp project that you can use as a starting point to develop your own prototypes
• A base Gradle configuration that brings in the dependencies you need to write and test a Corda 5 CorDapp
• A set of Gradle helper tasks which speed up and simplify the development and deployment process; these are effectively wrappers over the Corda CLI
• Debug configuration for debugging a local Corda cluster
• The MyFirstFlow code which forms the basis of the Getting Started documentation
• The ability to configure the members of the local Corda network

Downloading the CSDE

1. To obtain the CSDE template, clone the CSDE-Cordapp-Template-Kotlin repository:

   git clone https://github.com/corda/CSDE-cordapp-template-kotlin.git <local-folder>
   

2. Change to the new directory and checkout the Developer Preview 2 branch:

   git checkout release/corda-5-developer-preview-2
   

3. Initialise the git repo and change the remote so you do not inadvertently push your work back to our R3 repo.

4. Open the project in IntelliJ and let the import process complete. When complete, the project structure looks as follows:

   

Configuring the CSDE

The CSDE includes Gradle tasks to manage a local deployment of Corda. These Gradle tasks require Java Azul Zulu 11. To configure IntelliJ to use the correct Java version for Gradle, set Gradle JVM to Project SDK 11, as follows:

CSDE Overview

This section provides an overview of the content of CSDE. Other sections show you how to use it in the process of writing a CorDapp.

Project Structure

On the left, you can see the folder structure created, ready for CorDapps development.

You will write your flow code in src/main/kotlin/<your package path> and your flow tests in src/test/kotlin/<your package path>. (For Java, use src/main/java/<your package path> and src/test/java/<your package path> respectively.)

Gradle Helpers for the Combined Worker

On the right, you can see the Gradle tasks that we have included to help you work with a local deployment of Corda using the combined worker:

startCorda

The startCorda task does the following:

1. Downloads and locally stores a copy of the combined worker JAR, if required
2. Starts an instance of a Postgres Docker container; you will need Docker Engine or Docker Desktop running
3. Starts the combined worker

stopCorda

The stopCorda task does the following:

• Stops the Postgres database
• Stops the combined worker

deployCorDapp

The deployCorDapp task does the following to compile and deploy the CorDapp to the combined worker:

1. Compiles the CPB and CPI using the buildcpi task
2. Uploads the CPI to the combined worker
3. Generates the virtual nodes with the CPI

buildCPI

The buildCPI task compiles your CorDapp into a CPI file.

listVNodes

The listVNodes task displays a list of the virtual nodes on the local Corda cluster.

Debug Configuration

In the toolbar, you can select the DebugCorDapp run configuration to debug the running Corda from IntelliJ.