Java 9 Hackday

Videocap of interantional, online Java 9 hackday, held by the JUG
21 August 2017   449

vJUG is the first online Java Users Group. It allows for anyone from everywhere in the world to join and discuss all Java related topics. JUG conducts Hackdays on a regular basis.

Some info about the participants:

  • Heather VanCura is the Chair of the Java Community Process (JCP) Program at Oracle, international speaker, leader of Global Adopt-a-JSR program in conjunction with Java User Group leaders, organizer of developer hack days (aka Hackergartens) around the world and Spec Lead of JSR 364, Broadening JCP Membership, through the JCP Program. Heather is passionate about growing Java technology and community building dynamics.
  • Mani Sarkar is a passionate developer mainly in the Java/JVM space, currently living and working in the UK. A member of the London Java Community (LJC), JCP Member, OpenJDK contributor (has been heavily involved with this project in the past), involved in number of developer communities, and F/OSS projects. He sees himself working in the areas of core Java, JVM, JDK, Hotspot, Nashorn and Performance Tuning. Advocate of a number of agile and software craftsmanship practices and a regular at many talks, conferences and hands-on-workshops. Expresses his thoughts often via blog posts, tweets and other forms of social media. He can be found on twitter at @theNeomatrix369.
  • Simon Maple is the Director of Developer Relations at ZeroTurnaround, a Java Champion since 2014, JavaOne Rockstar speaker in 2014, Duke's Choice award winner, Virtual JUG founder and organiser, London Java Community co-leader and RebelLabs author. He is an experienced speaker, having presented at JavaOne, JavaZone, Jfokus, DevoxxUK, DevoxxFR, JavaZone, JMaghreb and many more including many JUG tours. His passion is around user groups and communities. When not traveling, Simon enjoys spending quality time with his family, cooking and eating great food.
  • Pratik Patel is the CTO of Atlanta based TripLingo  and the president of Atlanta Java User’s Group. He has also spoken at various conferences and participates in several local tech groups and startup groups. He’s in the startup world now and hacks Java, iOS, Android, HTML5, CSS3, JavaScript, Rails, and ….. well everything except Perl. 

 

What is Web3j?

Small review of lightweight Java and Android library for integration with Ethereum clients
15 December 2017   831

What is webj3?

web3j is a lightweight, highly modular, reactive, type safe Java and Android library for working with Smart Contracts and integrating with clients (nodes) on the Ethereum network:

web3j architecture
Web3j Architecture

This allows you to work with the Ethereum blockchain, without the additional overhead of having to write your own integration code for the platform.

According to the developers, these are the features:

  • Complete implementation of Ethereum's JSON-RPC client API over HTTP and IPC
  • Ethereum wallet support
  • Auto-generation of Java smart contract wrappers to create, deploy, transact with and call smart contracts from native Java code (Solidity and Truffle definition formats supported)
  • Reactive-functional API for working with filters
  • Ethereum Name Service (ENS) support
  • Support for Parity's Personal, and Geth's Personal client APIs
  • Support for Infura, so you don't have to run an Ethereum client yourself
  • Comprehensive integration tests demonstrating a number of the above scenarios
  • Command line tools
  • Android compatible
  • Support for JP Morgan's Quorum via web3j-quorum

It has five runtime dependencies:

  • RxJava for its reactive-functional API
  • OKHttp for HTTP connections
  • Jackson Core for fast JSON serialisation/deserialisation
  • Bouncy Castle (Spongy Castle on Android) for crypto
  • Jnr-unixsocket for *nix IPC (not available on Android)

It also uses JavaPoet for generating smart contract wrappers.

Lear more at GitHub.