ReCaptcha login form with Spring Security

Today I’ll show you how to customize Spring Security to create a login form with ReCaptcha verification

The captcha is based on Google ReCaptcha plugin. More info on ReCaptcha here

Design Pattern: the Asynchronous Dispatcher

Today we’ll revisit a common design pattern, the Observer, and one of its derivative for multi-threaded processing: the Asynchronous Dispatcher.

GWT JSON integration with Spring MVC

In the previous post, I’ve presented GWT RPC integration with Spring. In this post we’ll see how we can achieve JSON backend service integration between GWT and Spring MVC. We’ll re-use the same StockWatcher application and change the RPC communication into JSON requests.

GWT RPC integration with Spring

Recently I started studying GWT, a new web framework for my curriculum. The main idea of GWT is to let you code the GUI part in Java (with static compilation and type checking) then translate this code into Javascript.

For the backend, GWT relies on an RPC system using plain old Servlet. Each RPC service is published as a distinct servlet so you end up having as many servlets are there are distinct RPC services.

Not only this approach is not optimal for resources management server-side wise, it also pollutes your web.xml with many servlet declarations.

Ideally we should have an unique servlet serving as a router and dispatching RPC calls to appropriate service beans managed by Spring. Spring is an appropriate framework for managing business in the backend due to its industry-wide adoption and its mature extensions portfolio. Needless to say that this design can be easily adapted for JEE containers too.

Disclaimer: the code presented below has been inspired from projects like spring4GWT and gwtrpc-spring. I took the same approach and modified the URL mapping part so the original credits go for them.

Java 8 Lambda in details part V : Functional interface definition and lambda expression implementation

In this last post we’ll look at the functional interface formal definition and the way lambda expressions are implemented.

Java 8 Lambda in details part IV : Multiple inheritance resolution for defender methods

In this post we’ll look at conflict resolution rules for multiple inheritance introduced along with defender methods in JDK 8.

Java 8 Lambda in details part III : Method and constructor referencing

In this third post dedicated to Java 8 Lambda expressions, we’ll look at the new :: operator introduced to allow method and constructor referencing.