Simple CorDapp Example

This CorDapp serves as a demo for a simple use case of a vehicle trading application. The hypothetical scenario I used is AM General selling their newly manufactured Humvee NXT 360 to US military.

Although the project contains a Client folder, for the sake of simplicity I decided not to build the frontend.

The CorDapp templates for both Kotlin and Java can be found here:

• Kotlin
• Java

Pre-Requisites

See https://docs.corda.net/getting-set-up.html.

Running the nodes

On Windows

Open a terminal and go to the project root directory and type: (to deploy the nodes using bootstrapper)

• gradlew clean deployNodes

Then type: (to run the nodes)

• build/nodes/runnodes.bat

On Mac

• ./gradlew clean deployNodes
• ./build/nodes/runnodes

See example here: https://docs.corda.net/tutorial-cordapp.html#running-the-example-cordapp.

Interacting with the nodes

Shell

When started via the command line, each node will display an interactive shell:

Welcome to the Corda interactive shell.
Useful commands include 'help' to see what is available, and 'bye' to shut down the node.

Tue Nov 06 11:58:13 GMT 2018>>>

You can use this shell to interact with your node. For example, enter run networkMapSnapshot to see a list of the other nodes on the network:

Tue Nov 06 11:58:13 GMT 2018>>> run networkMapSnapshot
[
  {
  "addresses" : [ "localhost:10002" ],
  "legalIdentitiesAndCerts" : [ "O=Notary, L=London, C=GB" ],
  "platformVersion" : 3,
  "serial" : 1541505484825
},
  {
  "addresses" : [ "localhost:10005" ],
  "legalIdentitiesAndCerts" : [ "O=PartyA, L=London, C=GB" ],
  "platformVersion" : 3,
  "serial" : 1541505382560
},
  {
  "addresses" : [ "localhost:10008" ],
  "legalIdentitiesAndCerts" : [ "O=PartyB, L=New York, C=US" ],
  "platformVersion" : 3,
  "serial" : 1541505384742
}
]

Tue Nov 06 12:30:11 GMT 2018>>> 

You can find out more about the node shell here.

Running flows in this Cordapp

This cordapp contains only one flow class called ShipmentFlow. To run the flow execute the following command from the AM General's interactive shell:

• start com.template.flows.ShipmentFlowInitiator model: NXT 360, owner: US Military

Once the flow is completed, we can query the US military's vault using the following command (execute this from US military's window):

• run vaultQuery contractStateType: com.template.states.CarState