This tutorial is meant for those with a basic knowledge of Ethereum and smart contracts, who have some knowledge of Java, Android Studio and some basic programming knowledge but who are new to dApps.

• Setting up the development environment.
• Set up solidity and web3j.

Clone the project using git clone https://github.com/imraniot/digitalshop.git

Install NodeJS (includes NPM 5.5.1) from here https://nodejs.org/en/download/

Open terminal and run npm -g install solc

Download web3j from here as per for OC version https://github.com/web3j/web3j/releases

Now open android studio terminal and write

solcjs app\keystore\contracts\Product.sol --bin --abi --optimize --overwrite -o app\keystore\contracts\build

Then write down the below command

web3j solidity generate app\keystore\contracts\build\Product.bin app\keystore\contracts\build\Product.abi -o app\src\main\java -p io.left.core.newsblock.data.remote.contracts

Now we can use the contract api