In this chapter, we have scratched the surface of working with the Ethereum blockchain using your beloved language, Java. Indeed, it was a gentle introduction to web3j by building an Oracle-based application, opening the door to build complex Ethereum applications in Java. From now on, all you need is to dive deep into the web3j documentation. You will find a number of smart contract examples in their main project repository (https://github.com/web3j/web3j/tree/master/codegen/src/test/resources/solidity).

To enrich your knowledge, you can also explore EthereumJ, which is a Java implementation of the Ethereum protocol, or Ethereum Harmony. To step outside of the Java world, you can explore Web3py (https://github.com/ethereum/web3.py), which is a complete Python implementation of web3js.

In the next chapter, our Ethereum journey will continue as we examine how to use Ethereum as an infrastructure for business. We will, among other things, discover the interesting concept of blockchain as a service.

Stay tuned!