The Spring framework is a popular alternative to J2EE for enterprise application development. To download Spring or read about it, visit http://www.springsource.org/
The top 5 documented benefits of Spring are:
1. Spring saves the developer the time and effort required to write boiler plate code like JNDI lookups, creating JDBC connections, API specific exception handling etc. Every one has their horror story on not finding a JNDI reference and a framework that abstracts such plumbing code away from the application developer is certainly useful.
2. Spring is a lightweight framework. A lightweight framework should be small in size, conceptually simple and easy to use.
3. Spring simplifies database access. Most applications need to store and retrieve data from a relational database. There are many alternatives for database access such as JDBC, JPA, Hibernate, with varying levels of complexity. Spring provides a simpler abstraction over these APIs. Similarly it simplifies web development with its MVC framework.
4. Spring can used in various environments. It can be used in standalone J2SE applications. It can be used with a webserver such as tomcat. It can be used with a full blown application server like JBOSS or Websphere.
5. Spring lets you develop applications by assembling loosely coupled components. Loose coupling is a better design practice because it allows you to swap out moving parts without having to do major changes to the application. Spring achieves this by what it calls "Inversion of Control" and "Dependency Injection". Actually, it is mostly dependency injection.
Inversion of Control and Dependency Injection are a topic for a separate blog. But very briefly, in Spring, when you author a "bean", you specify the dependencies in an XML file and the Spring container makes them available. You don'nt have to explicitly create each dependency.
In subsequent blogs, using some code example, let us see if Spring delivers on its promise. I will dig deeper with examples and point out where Spring really simplifies development and where it just adds another layer of complexity. So stay tuned.