Run your CorDapp

Learning objectives

After you have completed this tutorial, you will know how to deploy, launch, and interact with the CorDapp that you built by following the previous tutorials.

The Corda network needed for this CorDapp includes one notary and two nodes, each representing a party in the network - Farmer Bob and Peter. A Corda node is an individual instance of Corda representing one party in a network.

Deploy and run your CorDapp on the test nodes:

• Notary, which runs a notary service.
• PartyA.
• PartyB.

Before you start

Before you run your CorDapp, check your work against the Apple Stamp CorDapp Java solution.

Deploy the CorDapp locally

1. Open the command line from the root of your project.

2. Compile your code into a Java application by running the deployNodes Gradle task:

• Unix/macOS: ./gradlew clean deployNodes.
• Windows: gradlew.bat clean deployNodes.

This builds three nodes with the CorDapp installed on them.

3. When the build finishes, go to the build/nodes folder.

You will see:

• A folder for each generated node
• A runnodes shell script for running all the nodes simultaneously on macOS.
• A runnodes.bat batch file for running all the nodes simultaneously on Windows.

Launch the sample CorDapp

To start the nodes and the sample CorDapp, run the command that corresponds to your operating system:

• Unix/macOS: ./build/nodes/runnodes.
• Windows: .\build\nodes\runnodes.bat.

The runnodes script creates a node tab/window for each node. It usually takes about 60 seconds for all the nodes to start. Each node displays Welcome to the Corda interactive shell along with a prompt.

Interact with your CorDapp

Follow the instructions in this section to interact with your CorDapp as Farmer Bob (PartyA node) and Peter (PartyB node).

Create and issue the AppleStamp voucher

In this first part of the process, Farmer Bob creates and issues a voucher to Peter for the apples he wishes to buy. He includes a description of the apples Peter requested (Fuji4072) and indicates that Peter is the holder of this new AppleStamp.

1. Go to the PartyA node window and run the command:

flow start CreateAndIssueAppleStampInitiator stampDescription: Fuji4072, holder: PartyB

This issues the AppleStamp to Peter. Farmer Bob and Peter both will have a copy of the AppleStamp voucher in their vaults.

2. Pull the data from the vault to verify if your transaction is performed correctly. Run the following command on both PartyA and PartyB nodes:

run vaultQuery contractStateType: com.tutorial.states.AppleStamp

You should see the same information in both vaults.

Package apples

Next, Farmer Bob prepares the amount of apples Peter requested by self-issuing a BasketofApples state.

1. Go to the PartyA node window and run the command:

flow start PackApplesInitiator appleDescription: Fuji10472, weight: 10

2. Pull the data from the vault to verify if your transaction was performed correctly. This is a self-issuance transaction so run this command on the PartyA node only:

run vaultQuery contractStateType: com.tutorial.states.BasketOfApple

If you run the same query on the PartyB node, you won’t get any data because they were not involved in this transaction.

Redeem the AppleStamp voucher

Finally, Peter goes to the orchard to pick up his apples and redeems his voucher. The voucher is marked as spent and Farmer Bob gives Peter his apples.

1. Go to the PartyA node window and run this command:

flow start RedeemApplesInitiator buyer: PartyB, stampId: <voucher ID of the voucher that you created in step 1>

2. Now you can query PartyB again to verify if they redeemed their AppleStamp voucher correctly:

run vaultQuery contractStateType: com.tutorial.states.BasketOfApples

Next steps

Follow the Write integration tests tutorial to finish this learning path.