Corda Training Solutions

This repo contains all the solutions for the practical exercises of the Corda two-day training course.

This repository is divided into two parts: Java Solutions, and Kotlin Solutions.

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.

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"

Solutions 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 Solution: 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 Solution: 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 Solution: 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:

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

Contract:

• Solution: 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 Solution: 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 Solution: 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 Solution: 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.