Java原教旨主义者的Web客户端开发技术

Question

I am a java developer and I would like to develop rich clients for the web. My problem is that I hate javascript, flash, etc. and most of the programming languages usually used for web client. I would be happy to keep doing java to develop web clients that may be used on common web browsers and, why not, on new fashion mobile devices. I am looking for some advices/warnings to make a good choice.

Java applet seems perfect for my case, but according to some rumors, it is not a really sustainable solution. Should I have a look at JavaFX? GWT? Are there some other possibilities?

Answer 1

What do you want to do? Vaadin is based on GWT and therefore utilizes HTML5 + JavaScript which is much slower than a Java Applet. I have tried boat and Applets with Swing is A LOT faster than Vaadin.

With Java Applets, Swing and Hessian you have unbeatable performance for business applications. Hessian is a very fast binary web service protocol. With JavaScript you are usually limited to text-encoded web service protocols like Json and various XML-based protocols. Text-based protocols consume a lot of CPU, memory and bandwidth compared to binary protocols - and they don't really provide you with any advantage at all.

The weak point of Applets is hardware accelerated graphics like OpenGL and multimedia. If you are developing games or movie players Applets is not that great.

JavaFX promise to fix hardware accelerated graphics performance and video codecs. With your description it is not clear if you need to wait for that.

However if you really need more than what standard applets will provide you than web start may be a solution. Its a bit like the old ActiveX with signed or unsigned application that gets extra privileges - either by being signed by sun or by asking the user. This will allow you to use JOGL or a 3d scene graph engine.

Answer 2

You are a perfect fit for JavaServer Faces (JSF). Yes just try them on. Look, you look great in them. The appeal of JSF is 1. It is a standardardized technology, part of Java EE 2. It relies a lot on Java programming over any JavaScript coding (which is not done at all). 3. JSF has been around for awhile, and it works quite well. In addition, JSF works with Ajax, out of the box (an added bonus), without writing a single syllable of JavaScript. The only downside is that you will have to code some html, and the "facelets" are basically html pages with some extra tags thrown in that you need to learn. But the vast majority of the real processing is done in Java. JSF also works without the extra baggage of Java EE, it was built to work with a plain Tomcat like server (or Glassfish or JBoss, etc) and a browser, and Java SE (the desktop version).

Answer 3

I think JavaFX looks very promising as a Java-based RIA technology. It's cutting edge though. Mac OS X and Linux versions are only available as a preview yet. Mobile and other device support has been announced but its not out yet, AFAIK.

Answer 4

Vaadin would also be suitable, requiring no Javascript or HTML at all, even for new component development. Page layout is done using layout managers (like Swing). New components can be composed from existing components (again, like Swing), or written from scratch using GWT (fairly straightforward, and pure Java).

There is a reasonable selection of add-ons covering some features not in the core framework.

The framework is very easy to use for Java developers with Swing experience, and has a polished look and feel out of the box. However, the layout managers do make it difficult to change the look and feel using CSS - simple tasks like adding borders are hard.

The layout is also quite "heavy", which means that Vaadin websites can feel slightly sluggish. In my experience, the feel is still better than some of the heavier JSF frameworks.

It is compatible with all major browsers.

Demonstrator: http://demo.vaadin.com/sampler/

You could also consider Wicket . This has a similar component-based approach, but the components are defined using simple HTML fragments, which results in a much lighter DOM (and therefore better browser performance) and far better control over the look and feel. Wicket has a steeper learning curve, however.

Answer 5

After trying GWT and struggling with its so-called "super-dev mode", I discovered JavaScript programming was not so painful. I forced myself to learn and practice and I finally fully adopted it. There are numbers of nice things in JavaScript and a huge number of libraries. My recommendation for people in my case is just to persevere in learning JavaScript using for example w3schools tutorial .