JAX London, 7-10 October 2019
The Conference for Java & Software Innovation

Developing Java applications on the Blockchain with web3j

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Monday, October 8 2018
09:00 - 17:00
Room E+F
Booking note:
Blockchain Workshop

This workshop is for anyone who wants to look beyond the hype and get some hands-on experience developing with blockchain technology. You’ll learn how to use and integrate Java applications with the dominant public blockchain Ethereum. We’ll also touch on the private blockchain technology Quorum.

Specifically, you will learn:

  • what a blockchain is
  • how the dominant public blockchain, Ethereum works
  • how the library web3j talks to Ethereum
  • what a smart contract is and how you can work with smart contracts from Java
  • web3j’s reactive API and how it uses the ReactiveX Observables to greatly enhance working with Ethereum
  • how to create and manage tokens via smart contracts on Ethereum
  • how to use the private blockchain technology Quorum with web3j-quorum

The workshop will provide an overview of what blockchain is, its evolution and some use cases to put everything into perspective. You’ll also have the chance to explore Ethereum, how it differs from Bitcoin and why you should use it.

We’ll discuss smart contracts and demonstrate how you can deploy and interact with a smart contract on Ethereum using the open source library web3j. We’ll go through some basic and advanced web3j features, demonstrating how RxJava fits into the picture. Last but not least, we’ll bring Quorum, an enterprise application of Ethereum, into the conversation.

The workshop is suitable for any level Java software engineers interested in blockchain.

The main requirement is to bring a laptop with Java 8. The optional requirements are to install the Solidity compiler and Geth.

  • Java 8
  • Gradle or Maven installed
  • Java Development IDE
  • Local admin rights on your machine for installing software

Optionally, if you’d like to get the following dependencies installed that will save some time at the start of the workshop:


  • Geth (https://github.com/web3j/web3j#start-a-client) synced against the Ropsten test network 
    • $ geth –rpcapi personal,db,eth,net,web3 –rpc –testnet


Behind the Tracks

Software Architecture & Design
Software innovation & more
Architecture structure & more
Agile & Communication
Methodologies & more
Emerging Technologies
Everything about the latest technologies
DevOps & Continuous Delivery
Delivery Pipelines, Testing & more
Cloud & Modern Infrastructure
Everything about new tools and platforms
Big Data & Machine Learning
Saving, processing & more