GWT for big projects? - gwt

My friend and I want to develop a big web2.0 project. We decided to write it in Java because we love it and we are good at it and the other libraries which we will use are written in Java (Apache Lucene, Apache Cassandra ...). and we choose GWT as a framework. We love google, google technologies, google apis.
and I want to ask do you think that GWT is suitable to launch the big projects like youtube, twitter, wikipedia and other... ? Is gwt-rpc mechanism reliable in big projects?

Well GWT is suitable for web applications and not web sites or web pages, GWT is suitable for applications like Gmail which is a BIG application yet contains a single page which has complex actions.
GWT fails in some projects with many pages, We used GWT in an ERP system which contained about 100 page each page represents CRUD operations + some business operations, GWT wasn't the perfect choice.
Other thing GWT may fail in is that web crawlers can't extract information from javascript files generated by GWT. Search engines prefer static HTML generated from server side, and not generated on client side by javascript as GWT does. So, Google search engine will not give results from your site.
In summary, GWT is suitable for web applications with fewer number of pages and more complex actions.

Your examples (youtube, twitter, wikipedia) are not good candidates for GWT, so if you're building that type of application you'll probably want to stick to traditional server based frameworks like SpringMVC or Spring Roo.
GWT is better suited for applications that would traditionally be desktop based and need to do a lot of processing on the client side such as email clients, games, reporting apps, word processors, etc...

I want to point out that "in big projects if generated javascript codes is larger and larger, User is obligated to wait to download js file before to use web site."

Related

GWT or Other Presentation Layer Technologies with Spring WebFlow/MVC Framework

First off, I've never used GWT before. I have good experience in HTML/CSS/JS/JSP.
I'm looking for people's opinions on the suitability of Google Web Toolkit for a brand new web app I'm developing.
A big requirement is that the UI is attractive and well designed (Does not look like a clunky Java/Swing App).
It should look like any typical HTML/CSS/JS based modern website.
It is an internal company application so no SEO is required.
JSF is not an option.
The web app frameworks used will be Spring Webflow and Spring MVC. It will use lightweight controllers to communicate with a service layer.
Would Spring Tiles combined with JSP be an easier or more flexible option than GWT for what I am trying to achieve?
Advantages/Disadvantages of GWT and other options welcome.
Thanks
Advantages of GWT
You don't really need to know any JavaScript, since all your client side code will be in Java
This is usually the main reason people go for GWT. They're backend developers who know Java but don't know Javascript, and they don't really want to learn it. Still, you should be careful about this. GWT is a very complete and complex framework with many concepts that are specific to GWT. Even though you'll be coding in Java you will still have to go through many tutorials and documentation before you can build a clean GWT app
Ready to use widgets, like date pickers, dynamic tables, layout panels, popups
It's not really specific to GWT. Other front end framework, like jQuery or Dojo or whatever also give you these. You can have a look at the GWT Showcase to see what GWT has to offer.
GWT takes care of a lot of complex and potentially dangerous stuff for you.
Stuff like Cross-Browser Support, Internationalization, Image and static resources bundling, Front end security, Ajax communication with a server, Events and MVP (just like MVC) framework support. Have a look at the documentation, it is very well done and very thorough.
Debugging is easy
GWT has two different 'modes'. When you're building your app for production, gwt will compile all the java code for the front-end that you wrote into javascript. This javascript will be executed in your clients' browsers. But when you're developping, you can run your app without compiling your java code to javascript. This lets you use a debugger to debug your interface. It's a very good tool.
Disadvantages of GWT
As I said before, GWT is a full framework, with concepts specific to it. Don't think that just because it's in java and you know java that you won't have to learn new stuff.
Interfacing GWT with back end frameworks is not easy
The most common way for your GWT client code to communicate with a server is by using GWT RPC mechanism. It means that you will need to have servlets that implement specific interfaces. You should definetly read the docs on client-server communication to see if that fits well with Spring. A search on SO or Google should give you pointers to setup your application.

Making a webserver using jsp and java

Using Google App Engine SDK:
webpage: http://hwsejk.appspot.com/
I'm trying to make a web server using java and jsp (it is a web server for an iPhone application). I don't know a lot about java so I'm having a lot of troubles trying to construct a server by myself. For now, I have tried implementing cookie, database, and some other methods. Now that I've given you basic information about my web server, I have a few questions to ask.
Is it the right approach to use java and jsp to make a web server like this? the java servlets get and send user inputs to different jsp pages, which contain some HTML and java code. But I've found some posts here that it's a bad practice to use jsp like this. I don't know how else I can make webpages. Could anyone please recommend the right approach to make a web server (like the one linked above)? I would love to know if there is some kind of a template that I can take a look at.
What you are making doesnt seem to be a "server" at all but rather a "web application" or "web site". The former implies you are creating a piece of sfotware to implement a specific protocol like HTTP, FTP, etc. while the latter is making a series of web pages or and application that runs on server.
You can create a web application in any number of languages, not just Java. From the screenshot you shared i would think that using Rails (Ruby), Django (Paython), or Symfony2 (PHP) would probably get you up and running pretty fast as it looks like you dont need much more than some basic model scaffolding with a pretty face.
If you are familiar with Java you might also want to try the Play! framework...

Is Google Web Toolkit is fine to develop database based web application?

Is Google Web Toolkit is fine to develop database based web application or do you have any other suggestion?
Thanks to answerers!
For a heavy Database based web application, nothing beats Grails. Check out this tutorial by IBM. It will show you the power of Grails and how easy it is to develop database based web applications in minutes. I love GWT and smartGwt, but will go for them over pure grails only if there is a lot of non-database based front end (client side) logic.
If you do not have a programming language of choice (Grails is groovy based, which is based on Java), you could even look at Ruby on Rails which was the inspiration for Grails itself.
Alternately, you can add both grails and gwt in the mix by using this gwt grails plugin so that you have a powerful database integration, as well as a powerful front end developer. (I haven't used this though)
Sure, but you will need to create your own RPC service to get records from server to client and to deliver modified records back the server. But it isn't difficult at all.
Alternatively you could also use SmartGWT, which is an extension for GWT with more widgets, etc. They have data bound objects but in free version would would need to create your own data sources. If you decide to buy a license they seem to have database integration out of the box.
And additional note to consider with SmartGWT is that it has relatively big download size - about 3MB uncompressed and almost 1MB compressed (HTTP server should compresse it; it is in HTTP standard and it is transparent). So if it is going to be a service in public internet it might get quite long to load (often exceeding magic 8 seconds).
I had been working on GWT (Google Web Toolkit) for 1.5 years and learned that its a perfect platform for developing web application which uses backend database for its operation unless you have the right skill sets working on your project and a basic design which is developed according to the requirement of your project.

Differences between GWT and Vaadin

Can anyone suggest whether "GWT" or "Vaadin" are a better choice to design an application? Also: what are the differences in coding style?
In GWT application logic is normally run on client side. It only calls server when it needs to read/save some data.
In Vaadin application logic is on server side. Client side must normally call server after every user interaction.
GWT advantage:
App logic (replies to user interaction) is faster as it is run locally in the browser. It's also relatively insensitive to bad network conditions. Network is used only when needed (to read/save new data), which saves net traffic (important for high traffic sites).
In this regard Vaadin is slower and introduces a lag in UI interaction which is annoying to user. If network is bad this will show in UI responsiveness.
Vaadin advantage:
App logic is run on the server so it can not be inspected by the user. Arguably (Vaadin claims) that makes it more secure.
A few more points:
A fundamental difference is that in GWT you have to separate your application into Client and Server code, no such distinction in Vaadin. This will affect the architecture of your application.
In GWT client code, you must code in Java, and have a limited subset of language features available (that the GWT compiler can translate into Javascript). In Vaadin, you can code in any JVM language, since everything runs in the server (I'm using Vaadin with Scala). This may or may not be relevant to you.
GWT compilation is VERY slow, although in development mode you have the emulator. This makes production environment updates painful (a GWT application I developed has grown pretty big, and currently takes around 15 minutes to compile).
It's very simple to extend GWT with 3rd party widgets, or roll your own. Creating new Vaadin widgets is more complex.
Another Vaadin advantage: you don't have to design or implement the client-server communication, that's built-in.
With Vaadin you can also use built-in GWT when you want to do something on the client-side. This gives you both simplicity of server-side programming model (no communications, no browser programming needed) with being full control of what happens in the browser.
Differences between Vaadin and GWT:
A) Vaadin includes a server-side development model that:
Cuts number of code lines to half by reducing layers one has to
implement for user interface.
Allows you to use any JVM based language for user interface - Scala,
Groovy
Increases security by keeping user interface logic in the server
Allows synchronous calls to any backend API from the web server
Allows use of any standard Java libraries and tools for UI layer- in
server side architecture applications
Does not need Java to JavaScript compilation step that often takes
time or makes tooling complicated in GWT projects - instead you have
the Vaadin client engine
Provides server push out of the box with no extra code needed
B) Vaadin provides a large set of high level user interface components. For GWT one would need to use commercial Sencha GXT for comparable component set.
C) Vaadin includes SASS based Valo theme engine that makes it easy to build good looking custom themes from your application. Valo is the latest theming for Vaadin.
D) Data binding: Vaadin has incorporated the ability to associate any widget directly to a data source such as database, file or anything else in the server-side. This enables to define default behavior of the widgets to act on data sources.
Vaadin vs GWT
tl;dr
whether "GWT" or "Vaadin" are a better choice to design an application
It is not an “either-or” question.
With Vaadin, you get GWT (or its counterpart, Web Components) plus much more.
Vaadin is a framework for building desktop-style web apps by writing pure Java code on the server-side including declaring a user-interface. That user-interface is rendered in a web browser by Vaadin automatically generating on-the-fly the necessary browser code: HTML, CSS, JavaScript, etc. Business logic executes only on the server-side. User events (buttons clicked, data typed into fields, etc.) on the web client trigger Java code to run on the server side.
How that browser code is generated and executed, and how the client and server communicate, depends on 3rd party technology:
In Vaadin 8 and earlier, GWT
In Vaadin 10 and later, Web Components
Vaadin 8 and earlier uses GWT
Vaadin 8 and earlier was built on top of Google Web Toolkit (GWT). GWT has been spun-out of Google, as a fully open-sourced project: http://www.GWTProject.org/
GWT cross-compiles Java code into standalone JavaScript files. GWT provides other important features such as support of UI components and client-server communications.
The Vaadin Ltd company is a major supporter of GWT, including having hosted GWT developer conferences, and providing consulting expertise services.
Vaadin is only one of many products built on GWT.
Vaadin 10 and later uses Web Components
Vaadin 10 and later, known as Vaadin Flow, is a major rewrite of the framework. Instead of using GWT underneath, Vaadin Flow is built on top of Web Components technology.
Web Components is actually a suite of technologies including Custom Elements, Shadow DOM, and HTML Templates. These technologies are now built into most every modern web browser, and supported on many older browsers via polyfills.
Writing a new widget component for Vaadin is much easier with Web Components than with GWT. And most any existing Web Components based component can be wrapped to provide access via Java from the Vaadin server-side framework.
I don't have a source at hand to cite, but as I recall, Web Components based widgets may run faster and use less memory than their GWT-based equivalents.
By the way, both generations of Vaadin depend on some other technology, such as the Atmosphere library for help with WebSocket and HTTP.
I haven't tried Vaadin. I'm a GWT fan, but I CAN say that I've been a bit disappointed by the default widget set provided with GWT. You really need something like SmartGWT to fill the framework out.
I belive Vaadin is a much more advanced framework than GWT
BUT
When it comes to optimise performance on the client side there is nothing much you can do unless you build your own components (and that's where the beauty of Vaadin stops)
In a project i'm working right now 90% of the staff I've done worked as a charm
And then I had to use an event timeline next to a couple of tables. When I loaded more than 400events on the timeline my web page was almost unusable not to mention terrible slow on initialisation. I've been trying to optimise the code the last two months. At the end I used a GWT component.
As any application has to show display information coming from the server, a major requirement for simple coding is automated data binding to your forms and tables.
With Vaadin, this is as simple as a few lines of code.
In GWT, first you have no table mapping.
As for forms, you can map an object to a form, but to do so you have to implement a so called GWT Editor for your object (and one for every object inside of it). An Editor is nothing else than the definition of the form to use to show/modify the object. So all in all, there is no automation here.
GWT enables you to write web-clients with Java. The GWT cross-compiler creates JavaScript code for the client-side. You have to care for the server for your own as well as client-server communication. The generated client-code is already optimized for many browsers. My personal opinion is, GWT was very popular until Google focused on Angular. Today it is not much popular anymore.
Vaadin provides two different solutions:
1) a UI widget-set based implementing the web-component standard, and
2) the Vaadin serverside Java framework. It allows you to write web-clients with Java. However, Vaadin generates the web-client through runtime on the server dynamically. Vaadin cares for the entire client-server communication. For rendering the UI, Vaadin until version 8 used a pre-compiled UI widget-set. Vaadin from version 10 uses the Vaadin web-components.
Further benefits of Vaadin:
You do not get in contact with HTML and JavaScript and you need not bother for DOM manipulation, browser history and other low-level problems
The serverside architecture provides better security
Modern themes
Individual styling with CSS
RapidClipse provides a powerful UI builder for Vaadin based on Eclipse containing a Vaadin <> JPA databinding, internationalization, UI persistence, extended Hibernate tools, JPA-SQL query language and MicroStream integration for creating Java in-memory database apps and microservices

Comparing GWT and Turbo Gears

Anyone know of any tutorials implemented across multiple web application frameworks?
For example, I'm starting to implement GWT's Stock Watcher tutorial in Turbo Gears 2 to see how difficult it will be to do in Turbo Gears 2.
Likewise, I'll be looking for a Turbo Gears 2 tutorial to implement in GWT.
But I hate to re-create the wheel - so I was wondering if anyone was familiar with such projects and/or would be interested in helping me work on such a project.
Thanks,
--Spencer
While it is possible to combine the two frameworks, I hope to convince you not to do so.
Most web-frameworks, including Turbogears, have server-side page flow management. A page is served to the user by generating html, user interacts by clicking on links or by posting a form, the browser sends a fresh request to the server, and finally server responds with new html altogether. You AJAX'ify the page by using a js library, or the framework has some support. But, in general, transition from one view to another is done on the server side.
GWT is totally different. There is only a single HTML page in the system. Once this page is downloaded, everything happens on the browser through javascript. When the user clicks on a link, its essentially just a javascript function call. History management is done through fragment urls (the portion after the #).
These two philosophies are poles apart. So apart that I daresay GWT doesn't work well with any server-side web technology. See this discussion on GWT vis-a-vis JBPM/Struts/Spring Webflow. And see this discussion on GWT v/s JQuery.