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In this article series, we are going to explore web frameworks from a Java point of view. It covers Java based frameworks and frameworks based on scripting languages that can run inside of a Java application server. The latter are for example Ruby, Python, PHP, Groovy based frameworks. This article is taken from my eBook 'The Web Framework Evaluation'. You can get the eBook at http://www.laliluna.de/shop. Difference between the free article and the eBook in PDF format. - eBook is printable
- eBook includes the upcoming detailed framework evaluations about 1-2 months earlier
- eBook includes a number of performance and load tests showing rendering performance and memory consumption under load.
Table of Content
In this article series, we are going to explore web frameworks. I
would like to answer a simple question at the end of our analysis
What is the
best web framework or technology for my web application?
Since 2007 I continuously tested web frameworks to find a suitable
solution to use after Struts 1. Over the last years, I have visited a
number of conferences (Java One 2009, Devoxx 2008, Java One 2008,
Jaxx 2007) and took the chance to listen to presentations on this
topic.
After all this testing and proof of concepts and exploration, I
really wanted to publish an article. Well, here it is.
I will name a lot of technologies in this article. You can find a
link and short description to all named technologies in the appendix.
Why is finding the best web technology so
difficult?
Basically because of two reasons. The technology landscape has
completely changed. A couple of years ago a web application was a
quite precise term for an application based on something like Struts
1, JSF, Tapestry, Cocoon or in worst case on plain JSPs with
servlets.
Today there is by far more choice of technologies and technologies
can even be combined.
Second, the requirements for modern web applications have rapidly
changed. We will explore both reasons in the following.
Let's have a look at the technology landscape first.
A short review of technical options
Javascript applications
There are applications rendered by Javascript on a single page.
The look and feel of these applications is close to that of desktop
applications running on your operating system. Technologies in this
area are Google Web Tool Kit (GWT), JMaki and Dojo.
Plugin based applications
The web application is rendered by a browser plugin. A number of
technologies compete with different concepts. Here you can find old
and new technologies like Adobe Flex, Microsoft SilverLight, JavaFX,
and Java Swing started with Webstart. You have read correctly, Java
Swing applications come to new life with the modern requirements of
more interactive web application.
Classical web frameworks of the new generation
In the classic web framework arena there is a new generation of
frameworks with the functionality already included which was missing
a couple of years ago. A complete list would include probably more
than 200 frameworks. Here just some candidates in alphabetic order:
Apache Shale, JavaServer Faces, JBoss Seam, MyFaces, Stripes, Struts
2, Tapestry and Wicket. The frameworks do either include Ajax
supporting tag libraries (with JSF you can use an external Ajax
components) or you can combine it with an Ajax library.
Ajax libraries and widget to spice up your life
There are Ajax library and Ajax widgets collections. Just to give
some more names: Jquery, Jquery UI components, Prototype,
Scriptaculous extension to prototype, Mootools, MochiKit and Rico.
They can be combined with the latter frameworks to spice them up and
provide the modern look and feel of web applications. Yahoo provides
a popular widget collection as well.
But still there is more.
JRuby, Jython, Groovy, Scala, PHP
Dynamic languages pours into our Java world. There are mature
languages like Ruby, Python, PHP and new languages like Scala and
Groovy which can nowadays be integrated more easily with Java. Based
on those languages you will find an even greater choice of web
frameworks.
In addition you can use dynamic languages to write Java Swing
applications.
RESTful application
Finally another technology becomes more
and more famous: RESTful web services and web applications. REST is
an acronym for Representational State Transfer. The origin of this
term is a dissertation from Roy Fielding. Roy researched typical
characteristics of the world wide web and defined principles for the
web which can be translated into principles for web applications.
Understanding these concepts is crucial as they are the basis for the
success of the web. RESTful application and RESTful webservices
strictly follow these principles.
RESTful applications use the underlying
protocols correctly. This will help us around a lot of frequent
problems of web applications and provides us with a very clean
approach. These principles are in conflict with stateful web
frameworks like Wicket or JavaServer Faces. You will see that, it is
going to be interesting to discuss the different approaches.
I would like to thank Stefan Tilkov for
his speech at the Devoxx conference, where he talked about the
importance of these characteristics for web applications.
New requirements for web application
New frameworks don't spring up like mushrooms if there is not a
demanding environment. There are a number of players who brought
forward new requirements. One is Macromedia who coined the term Rich
Internet Application (RIA) to describe their flash based technology.
Basically they mean an application started by a plugin, rendered on a
single web page which provides the look and feel of a desktop
application.
A little bit later the Ajax idea appeared to describe the use of
Javascript, asynchronous calls to the backend and CSS to make web
application more dynamic. We all know Ajax today but in fact its use
in web applications is still very basic.
In my opinion, we can summarize all this discussion pretty simply.
Web applications should look and feel like desktop applications.
How does a desktop application look? Well, let me explain it this
way. Open your OpenOffice Writer and well that's it. But at least,
let us try to put together a list of some typical characteristics.
Copy and Paste
Drag and Drop
Selecting content and applying an effect / function / format
Context menus = right click
Mouse Over effects
Menus
Menus can be accessed using keys
Keyboard short cuts can be defined to execute special
functions
Selecting content is actually a very wide area, starting from
selecting text up to selecting a number of elements in a
presentation
Visual components like sliders, panels, trees, table, grids,
input components, charts and diagrams
Control of the user interface, the user can close the
application but apart from this, you can control every piece on the
screen
Interacting with the underlying operating system, hard disk
access, connecting to the network
Interacting with other application which can be related to
Copy and Paste as well
There are quite a number of things which are available in desktop
applications. One thing, you should take for granted is that offering
support for this functionality in web application will come with a
trade off. Having access to the operating system clearly changes the
security concept of browsers. But this is already possible today but
not standardized. Have a look at technologies like Google Gears which
installs a browser plugin to let a web application interact with the
desktop and provides access to a local database.
Something that is not appreciated are the tradeoffs of desktop
applications like installation, uninstallation, operating system
dependency, etc.
At the end I would to introduce another requirement which is
addressed by technologies like Adobe Flex or JavaFX. These are
graphical effects including multi media content. These applications
no longer look like business applications but have rich animations
and do include all kinds of video, sound an animation. This can
require hardware rendering of a modern graphic card.
Summary
We had a first look on available web technology. Hopefully, you
got an impression of the wide choice we have.
There is a new generation of classic Java based web
frameworks either supporting Ajax with their tag libraries or
inviting you to use Javascript libraries to spice them up.
We named completely Javascript based applications running on
a single browser page.
Then there were technologies, also running on a single page,
but rendered by a plugin.
We had a quick lock in the world of dynamic languages.
Finally we spoke about RESTful applications.
Then we have talked about the so-called new requirement, didn't
waste to much time for this but just defined that there are two of
them
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