yxcho/cordapp-rpa

Project repo for coursework project on creating a simple smart contract on Corda

Background

This is the repo for the final project for ISFS603 Corporate Banking & Blockchain which demonstrates a simple smart contract functionality of creating a Receivables Purchase Agreement. This program is extended from the template on https://github.com/corda/cordapp-template-java

Note on terms used:
PartyA in the code refers to the liquidity provider in our report/ presentation
PartyB refers to the core enterprise in our report/ presentation

Pre-Requisites

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

Usage

Description of code functionalities

build.gradle - specifies node configurations
build/nodes/runnodes - code to start nodes
clients/build.gradle - start Spring Boot server for each party
contracts/src/main/java/com/template/schema/RPASchema.java - Database schema for our RPA
contracts/src/main/java/com/template/schema/RPASchema1.java - Database schema for our RPA
clients/src/main/java/com/template/webserver/Controller.java - HTTP server endpoints
workflows/src/main/java/com/template/flows/RPAIssueFlow.java - A sequence of steps that tells a node how to achieve a specific ledger update, such as issuing an RPA
contracts/src/main/java/com/template/states/RPAState.java - A state is an immutable object representing a fact known by one or more nodes at a specific point in time. You can use states to represent any type of data, and any kind of fact. For example, RPA amount, discount rate etc. State contains a reference to the contract.
contracts/src/main/java/com/template/contracts/RPAContract.java - Contracts govern the evolution of states. Contracts is similar to a legal contract in real world where it verifies whether the inputs are acceptable according to rules specified.

Running the program

1. Commands to run
   2.1 Run the deployNodes Gradle task:
   Unix/Mac OSX: ./gradlew deployNodes
   Windows: gradlew.bat deployNodes
   2.2 Start the nodes and the sample CorDapp:
   Unix/Mac OSX: ./build/nodes/runnodes
   Windows: .\build\nodes\runnodes.bat
   2.3 Start a Spring Boot server for Party A. Run the command:
   Unix/Mac OSX: ./gradlew runPartyAServer
   Windows: gradlew.bat runPartyAServer
   Repeat step 4.3 for Party B and then Party C in a new terminal
   Look for the Started Server in X seconds message — don’t rely on the % indicator.

2. Communication
   Use Postman or any other app to interact with CorDapp via HTTP endpoints (import Cordapp.postman_collection.json into postman)

Running the nodes

See 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.

Client

clients/src/main/java/com/template/Client.java defines a simple command-line client that connects to a node via RPC and prints a list of the other nodes on the network.

Running the client

Via the command line

Run the runTemplateClient Gradle task. By default, it connects to the node with RPC address localhost:10006 with the username user1 and the password test.

Via IntelliJ

Run the Run Template Client run configuration. By default, it connects to the node with RPC address localhost:10006 with the username user1 and the password test.

Webserver

clients/src/main/java/com/template/webserver/ defines a simple Spring webserver that connects to a node via RPC and allows you to interact with the node over HTTP.

The API endpoints are defined here:

 clients/src/main/java/com/template/webserver/Controller.java

And a static webpage is defined here:

 clients/src/main/resources/static/

Running the webserver

Via the command line

Run the runTemplateServer Gradle task. By default, it connects to the node with RPC address localhost:10006 with the username user1 and the password test, and serves the webserver on port localhost:10050.

Via IntelliJ

Run the Run Template Server run configuration. By default, it connects to the node with RPC address localhost:10006 with the username user1 and the password test, and serves the webserver on port localhost:10050.

Interacting with the webserver

The static webpage is served on:

http://localhost:10050

While the sole template endpoint is served on:

http://localhost:10050/templateendpoint