What is Web3j?

Small review of lightweight Java and Android library for integration with Ethereum clients
15 December 2017   815

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.

JDK 9 Hidden Gems

Mikael Vidstedt and Sandhya Viswanathan talk about JDK 9 optimizations spanning support for larger vectors
01 November 2017   782

What does JDK 9 mean to you? Modularization is the first thing that comes to mind, but there is a lot more. Come discover less-well-known but important technologies that Oracle has been working on with partners such as Intel to provide a higher-performance, lower-footprint, scalable Java with JDK 9.

This session talks about JDK 9 optimizations spanning support for larger vectors with enhanced vectorization, optimized math libraries, cryptography and compression acceleration, compact strings, new APIs with associated optimized implementation, and many more features that help big data, cloud, microservices, HPC, and FSI applications.

Speakers are:

  • Mikael Vidstedt, JVM Architect, Oracle
  • Sandhya Viswanathan, Senior Staff Software Engineer, Intel Corporation