Overledger Java SDK

Developer's guide to use the Overledger SDK written in Java by Quant Network.

Introduction to the Overledger SDK

Overledger is an operating system that allows distributed apps (MApps) to connect to multiple distributed ledger technologies (DLTs) or blockchains. The Overledger SDK allows developers to create signed transactions & send them simultaneously to all supported DLTs.

Technologies

The Overledger SDK is maven compatible dependency written in Java

Overledger SDK Structure

Overledger SDK Working Flow

Prerequisites

• Register for a free developer account on Quant Developer's Portal
• You will require MAppId and access key:
  • Enter information regarding your application in order to get a MApp ID.
  • Verfify your Quant token, and create a access key.

Installation

Developers would have to install the Overledger SDK as a maven dependency.

<!-- SDK bundle -->
<dependency>
    <groupId>network.quant</groupId>
    <artifactId>overledger-sdk-bundle</artifactId>
    <version>1.0.0-alpha.3</version>
</dependency>

Tailored installation

When a full implementation of all dependencies is not required, it can be tailored to only implement those services that will be utilised.

overledger-sdk-api

API module defines Overledger SDK interfaces.

overledger-sdk-essential

This module gives a basic implementation of Overledger SDK API.

overledger-sdk-bitcoin

This module contains Bitcoin implementation of Overledger Account API.

overledger-sdk-ethereum

This module contains Ethereum implementation of Overledger Account API.

overledger-sdk-ripple

This module contains Ripple implementation of Overledger Account API.

overledger-sdk-bundle

This module bundles up API, essential, Bitcoin, Ethereum and Ripple modules.

overledger-sdk-example

Includes some examples.

Getting started

• Follow README from overledger-sdk-api to create context.properties.

• Then load properties into OverledgerContext

OverledgerContext.loadContext(...);

• Instance OverledgerSDK Object, add accounts, and call Overledger SDK methods.

public class OverledgerSDKExample {
    
    private OverledgerSDK overledgerSDK;
    
    public OverledgerSDKExample(Account... accounts) {
        this.overledgerSDK = DefaultOverledgerSDK.newInstance(NETWORK.MAIN);
        this.overledgerSDK.addAccount(DLT.bitcoin.name(), accounts[0]);
        this.overledgerSDK.addAccount(DLT.ethereum.name(), accounts[1]);
        this.overledgerSDK.addAccount(DLT.ripple.name(), accounts[2]);
    }
    
    public OverledgerTransaction writeTransaction(OverledgerTransaction ovlTransaction) {
        return this.overledgerSDK.writeTransaction(ovlTransaction);
    }
    
}

actually working use case: note custom java properties only working and it must be laoded before the OverledgersSDK is instantiated.

            File fprop = new File("/Users/marvas/overledger-sdk-java/overledger-sdk-example/context.properties");
            UUID ovlId=null;
            FileInputStream inputStream = new FileInputStream(fprop);
            Properties properties = new Properties();
            properties.load(inputStream);
            OverledgerContext.loadContext(properties);
            OverledgerSDK h  = DefaultOverledgerSDK.newInstance();

            var ovTrans = h.readTransactions("network.quant.software");
            int cnt=0;

Further information

This SDK acts as library for embedding in an application, and facilitates the execution and access of Quant Network's Overledger.

Refer wiki for more Details.

Release notes