What are the Grails advantages over other Java Web Frameworks?

Question

I've worked with JSF, Spring MVC and Struts and I think I got a good level on these frameworks. Recently I heard that many good developers I worked with are learning Grails and using it in their projects.

What are the practical advantages of Grails over other frameworks? Is worth to learn it besides I know other frameworks? What is all the buzz around Grails, is it only because of Groovy?

NOTE: I did research in SO and the only related question I found was this and Grails is not mentioned

Answer 1

Grails is, like you say, built off Groovy which gives the immediate benefit of being more productive. The Groovy syntax is much terser than Java, it's much easier to do things in one line of Groovy code that would take you several in Java.

Grails specifically provides you with a number of advantages over other web frameworks (I can only talk for Struts 1.x, 2.x and SpringMVC however) - Grails is actually built on top of SpringMVC by the way and you can integrate other components using Spring.

• Database Migrations and Versioning - no more application out of sync with database schema syndrome. Most Java web apps suffer from this.

• Artefacts - which make creating new controllers and components easier. No more create a controller, configure it and stuff it into the right place in your web app. doh! Scaffolding also provides you with all some initial components to allow you to start building your pages and customising

• Simpler validation (def simpler than Struts 1.x), e.g. username(size:6..10, blank:false) specifies two validation rules for a username field to be of a specific length and non blank. It's a bit harder in the other Java web app frameworks.

• Built in Webflow (via Spring webflow) which makes creating complex workflows much simpler. Struts 2 can support Webflow, but via a plugin which is a little odd if I rememeber. Spring can too.

• Interceptors - SpringMVC also has these.

• Flash scope, see http://grails.org/doc/docs/1.1/ref/Controllers/flash.html

• Better data binding - Struts 2 is pretty good, much better than Struts 1. SpringMVC is also good.

There's a few more, check out the documentation for more details: http://grails.org/doc/1.1.1/