What is JavaServer Faces?

Small overview of a Java web application framework
01 September 2017   417

JavaServer Faces (JSF) is a framework for web applications written in Java. It serves to facilitate the development of user interfaces for Java EE-applications. Unlike other MVC frameworks that are managed by queries, the JSF approach is based on the components usage. The state of the user interface components is retained when the user requests a new page and then restores if the request is repeated. To display the data, JSP, Facelets is usually used, but JSF can be adapted to other technologies, for example XUL.

JavaServer Faces technology includes:

  • A set of APIs for representing user interface components (UI) and managing their state, processing events and validating input information, defining navigation, as well as supporting internationalization (i18n) and accessibility.
  • A special JSP tag library for expressing the JSF interface on a JSP page. In JSF 2.0, the Facelets technology is used as the view handler, which came to replace the JSP.

 

What is Web3j?

Small review of lightweight Java and Android library for integration with Ethereum clients
15 December 2017   816

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.