I am deciding if I should learn Groovy and Scala, and currently I am comparing web frameworks. I like the Groovy language a bit more, but Play! works with both Java and Scala. Another thing pointing me towards Play! is the tight CoffeeScript Integration. For collaboration purposes, I need my framework to be able to affectively communicate and interact with some sort of JavaScript. For my choice I have a few questions on the Grails frameworks.
Questions
Can Grails use Java, or just Groovy?
Does Grails have any tight JavaScript integration? I mean can the two technologies communicate at runtime?
The Eclipse Grails Project seems to be maintained by spring. Does this mean Groovy can use Spring?
I am still confused on which to learn. Hopefully the answers to these questions will help me decide which to learn.
All of this information is widely available on the internet, easily found using Google or your favorite search engine. That said, here are the answers to your questions:
Question: Can Grails use Java, or just Groovy?
Answer: Grails uses both. Groovy is a dynamic language which runs within the JVM and in a lot of ways extends Java. Grails uses both Java and Groovy. You can use both within your Grails project as well. This allows you to leverage the vast array of Java libraries available. Much like Grails itself does.
Question: Does Grails have any tight JavaScript integration? I mean can the two technologies communicate at runtime?
Answer: Any Javascript library can be used, and they can (if you make them) communicate at runtime. (Your question doesn't really make a lot of sense). In regards to coffeescript (which you mentioned in your question), there are plugins available that will compile coffeescript at build time for your Grails project.
Question: The Eclipse Grails Project seems to be maintained by spring. Does this mean Groovy can use Spring?
Answer: Grails is built upon Spring, so yes. You (and it) can use Spring. There are a great number of reasons to leverage the Spring framework within your Grails project, and with the Bean builder DSL it's fairly straight forward to do so.
Matt Raible has a great comparison of all the JVM frameworks. I suggest checking out Play and Grails within that comparison to see how they rank in the broader comparison...
http://www.slideshare.net/mraible/comparing-jvm-web-frameworks-february-2014
You can very well use Java in Grails framework. There are two options:
1. Grails has a separate source folder for Java - here you can use Java classes
2. You can also use Java code inside a Groovy classes
Grails uses Spring and Hibernate
Try both out. Choosing a web framework is a big decision and it's worth spending some time choosing.
Related
We are about to take on a large project implemented in Grails (2.3.7). The application makes heavy use of many different (end-points as well) REST-ful webservices. We are of course interested in using what is considered to be "best standards" (at least currently).
We are currently considering:
- Using the Groovy HTTP-builder
- Using the "REST Client builder" plugin
Any other we should consider and what are your experiences using the above mentioned?
I have used both http://grails.org/plugin/rest and http://grails.org/plugin/rest-client-builder and both provide a nice wrapper around HTTP Builder library. The "rest" plugin provides dynamic methods for you if you like using that syntax. I prefer REST client builder though. Both are easy to work with.
Does Spring MVC now fully support using Scala as a language?
Are there any things that are problamatic or that take some special configuration/setup?
I personally just use spring mvc, IoC and then database helpers for hibernate (not really the security modules etc).
I am not sure if you are looking for any Scala specific features, but I have been using Spring MVC and Scala for over a year now. You can see my sample applications here and here that use Scala and Spring MVC.
That said, the integration of Scala and Spring framework could be better as the framework does not take advantage of Scala features out of the box. This is being addressed as part of the Spring Scala project which has reached release-candidate stage. There is a basic blog post explaining the project features and high level goals.
I know Scala Lift applications can be put into a Java EE server. And Scala Lift seems to compete/substitute JSF as presentation layer of Java EE.
Will I be able to use EJBs and JPA in a Lift application? And if yes, could it be also possible to use JSF alongside Lift as a fallback, like URLs with one prefix go to Lift and with another to JSF?
Yes, you can use EJB and JPA in a Lift app. Just call your java methods from within Lift snippets. Just like any Java application, if it is on the classpath, you can use it.
As to your second question, anything is possible. The only sane way I can think about doing what you're describing would be to configure your servlet filters (in WEB-INF/web.xml) to pass some requests to Lift and others to JSF. You could also cook up a way to do this within either JSF or Lift, essentially proxying certain requests from one to the other. It is hard to imagine a use case that would justify such ugliness, but it is possible.
As a Java developer new to the web development environment, I was quite excited to find Grail which provides a great framework especially the convenience of abstracting DB operations with ORM. I later learned that it is actually the function of hibernate. At the same time I am delighted to learn about GWT. It is a god send for the project. I can continue building applications with event driven widgets using Java. Yeah!!
The answer seems clear: GWT + Hibernate. Will it work? What do I miss? Why there is much talk about this set up? What is the concern or area of risk? Have anyone tried this before?
Or, how do GWT developers handle the challenge of data persistence? What are the options?
Also I can't seem to find a good tutorial about setting up Hibernate with Eclipse -- the IDE I am familiar with. What are the tools or plug-ins needed?
Hibernate works fine with GWT as long as you keep in mind that the GWT code is actually running on the browser so you can't manipulate Hibernate objects in your client code. The downside to that is you're probably going to have duplicate objects on the client and server side, but you can use course-grained DTOs via the GWT remote procedure calls. On the server side, just create a ServletListener to initialize your Hibernate project and then use normal Hiberate methods to store and retrieve objects.
As far as Hibernate and Eclipse, Hibernate has an Eclipse plugin, but it's not really necessary to develop in Eclipse. It gives you the ability to run HQL and to reverse engineer Java objects from the database or vice versa, which can be useful, but it's not required.
If you want to go the hibernate way, you should have a look at Gilead or its predecessor hibernate4gwt. It works pretty well, but documentation is a bit sparse.
I wanted to know if it was possible to use Spring MVC with a different JVM language than Java, e.g. Groovy or Scala. Or can Groovy only be run on Grails?
Also if it is possible, is this something which people try often, or do they just stick to the framework traditionally used?
Spring works perfectly well with scala because scala compiles to normal .class files which are Java-equivalent bytecode. I use Spring and scala all the time. It's even possible to use the Spring XML-extensibility to add support for scala-specific types, for example:
<bean class="my.scala.Class">
<property name="listProp">
<scala:list value-type="java.lang.Integer">
<value>1</value>
</scala:list>
</property>
</bean>
Sure, spring has excellent support for dynamic languages like Groovy. There is an entire chapter in the reference manual: http://static.springsource.org/spring/docs/2.5.6/reference/dynamic-language.html
As for scala; I tried doing this and it is possible. The problem is that JSP (or for that matter most templating languages supported by spring mvc) doesn't 'understand' scala collection types so I found myself converting between scala and java collections quite a lot. This should be better in Scala 2.8.0 but I haven't tested this myself.
Grails is implemented with Spring baked in, Grails 3 uses Spring-Boot. So that is definitely possible. You could also use Scala with Spring MVC. I don't know that you'd get the most mileage out of Scala with Spring MVC -- not a lot of opportunities to use Scala's functional programming features -- but there's nothing stopping you from trying it out.
I cannot speak for Scala, but I have personally used Spring with Groovy. Match made in heaven :)
Spring works very well with Scala, although Scala itself has features that mean you don't need
a dependency injection framework (such as Spring) in many cases.
Also, Scala isn't a dynamic language, it's a static language just as Java is. One of the primary goals of Scala was maximum interoperability with Java. This means that Scala compiles down to class files that look and feel just like Java objects, and can be seamlessly used as Java objects by external libraries and frameworks, such as Spring.
Well, what about writing the business logic in scala, so that the functional way scales well in multic core environments and let the rest handled by Spring and Hibernate. I think this is a pretty nice way to get the best of both worlds. Of course one can usw lift as a web app framework, but i think Spring is more actually mature and has more features. But the business logic is where the ball is rolling and so Scala and FP can handle this better than imperative java.
Right?
Your question should be classified:
groovy or scala compile to class and deployed
groovy not compile just deployed to tomcat
using traditional spring framework with a little groovy
using brand new framework to work with groovy e.g. grail
If you want using traditional spring framework e.g. spingmvc springcloud and want to add some groovy to implement business logic code, please use a new lib micro-mvc: https://github.com/jeffreyning/micro-mvc
This lib can scan interface as springbean and create a proxy to execute groovy.