Corda Training Template

This repo contains all of the instructions and class templates for the practical exercises of the Corda two day training course.

This repository is divided into two parts: Java templates, and Kotlin templates. You may complete the training in whichever language you prefer.

To all external trainers:

This repo will have a major upgrade on March 26th. The primary changes will be

1. Corda version bump
2. Cordapp structural changes: separate flows and contracts/states
3. Spring server rewrite.

The upgraded code is done and you can see the preview at branch 4.4-update

Setup

Tools

• JDK 1.8 latest version
• IntelliJ latest version (2017.1 or newer)
• git

After installing the required tools, clone or download a zip of this repository, and place it in your desired location.

IntelliJ setup

• From the main menu, click open (not import!) then navigate to where you placed this repository.
• Click File->Project Structure, and set the Project SDK to be the JDK you downloaded (by clicking new and nagivating to where the JDK was installed). Click Okay.
• Next, click import on the Import Gradle Project popup, leaving all options as they are.
• If you do not see the popup: Navigate back to Project Structure->Modules, clicking the + -> Import button, navigate to and select the repository folder, select Gradle from the next menu, and finally click Okay, again leaving all options as they are.

Instructions

Once you are all set up, you can start expanding on the class templates. This project follows a test-based development style - the unit tests for each class contain all the information you will need to complete this CorDapp.

All the tests are commented out by default - to complete this training, you will uncomment them one at a time, building up the CorDapp until it passes everything.

You will begin by opening IOUState and IOUStateTests in your language of choice and uncommenting the first test. Then, use the TODO and hints to modify IOUState to pass the test.

In order to issue IOU's using Corda - You will first fix IOUState, then IOUContract, and lastly IOUIssueFlow. Then you can move on to more challenging exercises specified in Transfer and Settle testing files.

Running the tests

• Kotlin: Select Kotlin - Unit tests from the dropdown run configuration menu, and click the green play button.
• Java: Select Java - Unit tests from the dropdown run configuration menu, and click the green play button.
• Individual tests can be run by clicking the green arrow in the line number column next to each test.
• When running flow tests you must add the following to your run / debug configuration in the VM options field. This enables us to use
• Quasar - a library that provides high-performance, lightweight threads.
• "-javaagent: /PATH_TO_FILE_FROM_ROOT_DIR/quasar.jar"

Template Files

Kotlin

State:

• Template: kotlin-source/src/test/kotlin/net/corda/training/state/IOUState.kt
• Tests: kotlin-source/src/main/kotlin/net/corda/training/state/IOUStateTests.kt

Contract:

• Template: kotlin-source/src/main/kotlin/net/corda/training/contract/IOUContract.kt
• Issue Tests: kotlin-source/src/test/kotlin/net/corda/training/contract/IOUIssueTests.kt
• Transfer Tests: kotlin-source/src/test/kotlin/net/corda/training/contract/IOUTransferTests.kt
• Settle Tests: kotlin-source/src/test/kotlin/net/corda/training/contract/IOUSettleTests.kt

Flow:

• Issue flow template: kotlin-source/src/main/kotlin/net/corda/training/flow/IOUIssueFlow.kt
• Issue flow tests: kotlin-source/src/test/kotlin/net/corda/training/flow/IOUIssueFlowTests.kt
• Transfer flow template kotlin-source/src/main/kotlin/net/corda/training/flow/IOUTransferFlow.kt
• Transfer flow tests: kotlin-source/src/test/kotlin/net/corda/training/flow/IOUTransferFlowTests.kt
• Settle flow template kotlin-source/src/main/kotlin/net/corda/training/flow/IOUSettleFlow.kt
• Settle flow tests: kotlin-source/src/test/kotlin/net/corda/training/flow/IOUSettleFlowTests.kt

The code in the following files was already added for you:

• kotlin-source/src/main/kotlin/net/corda/training/plugin/IOUPlugin.kt
• kotlin-source/src/test/kotlin/net/corda/training/Main.kt
• kotling-source/src/main/kotlin/net/corda/training/plugin/IOUPlugin.kt
• kotling-source/src/main/java/kotlin/corda/training/flow/SelfIssueCashFlow.kt

Java

State:

• Template: java-source/src/main/java/net/corda/training/state/IOUState.java
• Tests: java-source/src/test/java/net/corda/training/state/IOUStateTests.java

Contract:

• Template: java-source/src/main/java/net/corda/training/contract/IOUContract.java
• Issue Tests: java-source/src/test/java/net/corda/training/contract/IOUIssueTests.java
• Transfer Tests: java-source/src/test/java/net/corda/training/contract/IOUIssueTests.java
• Settle Tests: java-source/src/test/java/net/corda/training/contract/IOUIssueTests.java

Flow:

• Issue template: java-source/src/main/java/net/corda/training/flow/IOUIssueFlow.java
• Issue tests: java-source/src/test/java/net/corda/training/flow/IOUIssueFlowTests.java
• Transfer template: java-source/src/main/java/net/corda/training/flow/IOUTransferFlow.java
• Transfer tests: java-source/src/test/java/net/corda/training/flow/IOUTransferFlowTests.java
• Settle template: java-source/src/main/java/net/corda/training/flow/IOUSettleFlow.java
• Settle tests: java-source/src/test/java/net/corda/training/flow/IOUSettleFlowTests.java

The code in the following files was already added for you:

• java-source/src/main/java/net/corda/training/plugin/IOUPlugin.java
• java-source/src/test/java/net/corda/training/NodeDriver.java
• java-source/src/main/java/net/corda/training/plugin/IOUPlugin.java
• java-source/src/main/java/net/corda/training/flow/SelfIssueCashFlow.java

Running the CorDapp

Once your application passes all tests in IOUStateTests, IOUIssueTests, and IOUIssueFlowTests, you can run the application and interact with it via a web browser. To run the finished application, you have two choices for each language: from the terminal, and from IntelliJ.

Kotlin

• Terminal: Navigate to the root project folder and run ./gradlew kotlin-source:deployNodes, followed by ./kotlin-source/build/node/runnodes
• IntelliJ: With the project open, select Kotlin - Node driver from the dropdown run configuration menu, and click the green play button.

Java

• Terminal: Navigate to the root project folder and run ./gradlew java-source:deployNodes, followed by ./java-source/build/node/runnodes
• IntelliJ: With the project open, select Java - NodeDriver from the dropdown run configuration menu, and click the green play button.

Interacting with the CorDapp

Once all the three nodes have started up (look for Webserver started up in XXX sec in the terminal or IntelliJ ), you can interact with the app via a web browser.

• From a Node Driver configuration, look for Starting webserver on address localhost:100XX for the addresses.

• From the terminal: Node A: localhost:10009, Node B: localhost:10012, Node C: localhost:10015.

To access the front-end gui for each node, navigate to localhost:XXXX/web/iou/

Troubleshooting:

When running the flow tests, if you get a Quasar instrumention error then add:

-ea -javaagent:lib/quasar.jar

to the VM args property in the default run configuration for JUnit in IntelliJ.

Solutions are available here.