For me the biggest shortcoming of JSF is poor support for programmatically (dynamically) generated pages. If you want to construct your page (create page component model) dynamically from java code. For example if you are working on WYSIWYG web page constructor. Adequate documentation of this use case in not generally available. There are many points where you have to experiment and development is quiet slow. Many things just don't work how you would expect. But generally its possible hack it somehow. Good thing is that it's not problem in philosophy or architecture of JSF. It's simply not elaborated enough (as far as I know).

JSF 2带来了组合组件，这将使组件开发变得容易，但是它们对动态(编程式)构造的支持非常差。如果你克服了动态组合组件构造的复杂且几乎没有文档的过程，你会发现如果你把几个组合组件嵌套得稍微深一点，它们就会停止工作，抛出一些异常。

但是JSF社区似乎意识到了这个缺点。你可以从这两个bug中看到，他们正在研究这个 http://java.net/jira/browse/JAVASERVERFACES-1309 http://java.net/jira/browse/JAVASERVERFACES_SPEC_PUBLIC-599

至少在谈论规范时，JSF 2.2的情况会更好。

JSF有很多优点，关于缺点的问题，让我再补充一点。

在实现一个web项目的实际场景中，在一个时间框架内，你需要注意以下因素。

你的团队中是否有足够多的资深成员提出最好的建议 适合每个场景的控件? 你有足够的带宽来适应最初的学习曲线吗? 您的团队中是否有足够的专家来审查JSF 开发者制作的东西?

如果你对这些问题的回答是“不”，你可能会在不可维护的代码库中结束。

我想到了一些缺点:

JSF is a component-based framework. This has inherent restrictions that have to do with obeying the component-model. AFAIK JSF supports only POST, so if you want a GET somewhere you have to do a plain servlet/JSP. Most components try to provide abstractions over domains like relational databases and front-end JavaScript, and many time these abstractions are "leaky" and very hard to debug. These abstractions might be a good starting point for a junior developer or someone not comfortable with a particular domain (e.g. front-end JavaScript), but are very hard to optimise for performance, since there are several layers involved, and most people that use them have little understanding of what is going on under the hood. The templating mechanisms that are usually used with JSF have nothing to do with how web desigers work. The WYSIWYG editors for JSF are primitive and in any case, your designer will give you HTML/CSS that you'll have to spend ages converting. Things like EL expressions are not statically checked and both the compiler and IDEs are not doing a good job at finding errors, so you'll end up with errors that you'll have to catch at run-time. This might be fine for dynamically typed language like Ruby or PHP, but if I have to withstand the sheer bloat of the Java ecosystem, I demand typing for my templates.

总而言之:使用JSF节省的时间，从避免编写JSP/servlet/bean样板代码，您将花费10倍的时间来使其可伸缩并完全按照您的要求进行操作。

“JSF将输出视图层HTML和JavaScript，如果不进入控制器代码，您就无法控制或更改它们。”

实际上，JSF为您提供了灵活性，您既可以使用标准/第三方组件，也可以创建自己的组件，您可以完全控制呈现的内容。使用JSF 2.0创建自定义组件只需要一个xhtml。

对我来说，JSF 2.0最大的缺点不仅是JSF的学习曲线，而且是为了让它做有用的工作而必须使用的组件库。想想你要真正精通需要处理的数量惊人的规范和标准:

HTML in the various incarnations. Don't pretend you don't need to know it. HTTP -- when you can't figure out what is going on you have to open Firebug and see. For that you need to know this. CSS -- Like it or not. It isn't so bad really and there are some nice tools out there at least. XML -- JSF will probably the first place you use namespaces to this degree. Servlet Specification. Sooner or later you will get into calling methods in this package. Aside from that you have to know how your Facelets gets turned into XHTML or whatever. JSP (mostly so you know why you don't need it in JSF) JSTL (again, mostly to cope with legacy framework) Expression Language (EL) in its various forms. ECMAScript, JavaScript, or whatever else you want to call it. JSON -- you should know this even if you don't use it. AJAX. I would say JSF 2.0 does a decent job of hiding this from you but you still need to know what is going on. The DOM. And how a browser uses it. See ECMAScript. DOM Events -- a topic all by itself. Java Persistence Architecture (JPA) that is if you want your app to have any back end data base. Java itself. JSEE while you are at it. The Context Dependency Injection specification (CDI) and how it clashes with and is used with JSF 2.0 JQuery -- I would like to see you get along without it.

现在，一旦你完成了这些，你就可以继续使用专有规范，即你将在此过程中获得的组件库和提供者库:

PrimeFaces(我选择的组件库) RichFaces MyFaces ICEFaces EclipseLink(我的JPA提供者) Hibernate 焊接

别忘了容器!所有这些配置文件:

GlassFish(2,3等) JBoss Tomcat

那么——这让事情变得简单了吗?当然，JSF 2.0很“简单”，只要你想做的只是最基本的web页面和最简单的交互。

简单地说，JSF 2.0是当今软件界所存在的最复杂和最麻烦的技术大杂烩。我想不出还有什么更好的方法。

Inexperienced developers usually will create applications that are painfully slow and code will be really ugly and hard to maintain. Its deceptively simple to start, but actually requires some investment in learning if you want to write good programs. At least at the start you will often "stuck" on some problem and will spend more time reading balusc posts on internet than actually working :) After a while it will be less and less of that, but it still can be annoying. Even more annoying when you find out that the problem is not due to you lack of knowledge/mistake but actually a bug. Mojarra was(is?) quite buggy, and another layer of components adds even more problems. Richfaces was biggest piece of crap software ever written :) Don't know how it is now on version 4. We have Primefaces which is better, but still you will run into bugs or lack of features especially with more exotic components. And now you will need to pay for Primefaces updates. So I would say its buggy but its getting better especially after 2.2 version fixed some problems with spec. Framework getting more mature but still far from perfect (maybe myfaces better?). I don't find it especially flexible. Often if you need something very very customized and there are no components that does that - it will be a bit painful. Again I'm talking from average developer perspective - the one with deadlines, quick reading tutorials, and searching stackoverflow when getting stuck because no time to learn how it really works :) Often some components seems to have "almost" what you need, but not exactly and sometimes you might spend too much time to make it do something you want :) Need to be careful in evaluating if its better to create your own or torture existing component. Actually if you are creating something really unique I would not recommend JSF.

简而言之，我的缺点是:复杂，开发过程不流畅，漏洞百出，缺乏灵活性。

当然也有好处，但这不是你问的。不管怎样，这是我使用框架的经验，其他人可能有不同的意见，所以最好的方法是尝试一段时间，看看它是否适合你(只是一些更复杂的东西-不是天真的例子- JSF真的很出色:)依我看，JSF的最佳用例是业务应用程序，如crm等…