https://github.com/web3j/web3j-corda
Lightweight JVM library for integrating with Corda
https://github.com/web3j/web3j-corda
corda dlt kotlin web3j
Last synced: 6 months ago
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Lightweight JVM library for integrating with Corda
- Host: GitHub
- URL: https://github.com/web3j/web3j-corda
- Owner: web3j
- License: apache-2.0
- Created: 2019-10-18T14:07:05.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2023-07-22T19:09:23.000Z (over 2 years ago)
- Last Synced: 2024-05-01T09:43:04.396Z (over 1 year ago)
- Topics: corda, dlt, kotlin, web3j
- Language: Kotlin
- Homepage: https://corda.web3j.io
- Size: 107 MB
- Stars: 14
- Watchers: 12
- Forks: 6
- Open Issues: 7
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
web3j Integration for Corda
===========================
## Introduction
web3j-corda is a lightweight client library for working with CorDapps and interacting with different nodes on Corda networks.
## Features
- Connect to a Corda node
- Query the available CorDapps on the node
- Generate CorDapp client wrappers to interact with the deployed CorDapps
- Generate integration tests using Docker containers to verify CorDapps in real Corda networks
- Generate sample projects with a CorDapp contract, workflow and client modules
## Requirements
* Java SDK 1.8
* Docker (for integration tests)
## Quick start
### Using the web3j-corda CLI
There is a web3j-corda binary that allows you to easily:
* Generate a template CorDapp project and the respective client wrappers
* Generate client wrappers for existing CorDapps
You can install web3j-corda by running the following command in your terminal:
```shell
curl -L https://raw.githubusercontent.com/web3j/corda/master/scripts/installer.sh | bash
```
### Create a template CorDapp project
To generate a template CorDapp project with the client wrappers:
```shell
web3j-corda new --name= --output-dir= --package-name=
```
### Create CorDapp client wrappers
To generate a web3j-corda client wrappers to existing CorDapps:
```shell
web3j-corda generate (--url= | --cordapps-dir=) --output-dir= --package-name=
```
For further instructions, head to the [Examples](https://corda.web3j.io) section in the docs.
## Getting started
Add the relevant dependency to your project:
### Maven
```xml
org.web3j.corda
web3j-corda-core
0.2.8
```
### Gradle
```groovy
dependencies {
implementation 'org.web3j.corda:web3j-corda-core:0.2.8'
}
```
## Connect to a Corda Node
Initialise a connection, and create our Corda client service:
```kotlin
val service = CordaService("http://localhost:9000/") // URL exposed by Corda OpenAPI connector
val corda = Corda.build(service)
```
Obtain all the nodes connected to the current node:
```kotlin
val nodes = corda.api.network.nodes.findAll()
```
To query the list of all running CorDapps:
```kotlin
val corDapps = corda.api.corDapps.findAll()
```
To start a flow there are two option depending on whether you want to use a generated CorDapp wrapper
or just the Corda API directly:
### Using Corda API
This way works but is not type-safe, so can lead to runtime exceptions:
```kotlin
// Initialise the parameters of the flow
val params = InitiatorParameters("$1", "O=PartyA, L=London, C=GB", false)
val issue = corda.api
.corDapps.findById("obligation-cordapp")
.flows.findById("issue-obligation")
// Type-conversions with potential runtime exception!
var signedTx = issue.start(parameters).convert()
```
### Using the Web3j CorDapp wrapper
By using a wrapper generated by the `web3j-corda` Command-Line Tool,
you can interact with your CorDapp in a type-safe way:
```kotlin
// Initialise the parameters of the flow
val params = InitiatorParameters("$1", "O=PartyA, L=London, C=GB", false)
// Start the flow with typed parameters and response
val signedTx = Obligation.load(corda.service).flows.issue.start(parameters)
```
## Documentation
The project documentation portal is available [here](https://corda.web3j.io).
To build and serve the docs locally, you will need to have [Pipenv](https://pipenv.readthedocs.io/en/latest/) installed. Then simply run:
```shell
pipenv install
pipenv run mkdocs serve
```
## Support
[Web3 Labs](https://www.web3labs.com) maintain web3j-corda. If you'd like to get in touch, please [email us](mailto:hi@web3labs.com?subject=web3j-corda).