是否有一个基于Java的Web模板引擎之类的JSP，可以从持久性存储中加载页面模板？

Question

I would like to provide users to write plugins to my application, the initial design and implementaion involve a Velocity (VTL) template engine to allow

• Secure : uesrs can't call internall Java code (without hacking using reflection)
• Simple : Limited and confined API, I can write my own domain specific language
• Portable : I can store VTL templates in a JAR, in the database or anywhere I like
• Decoupled : template context and logic / controller is not coupled to the web / HTML

Then with the limitations of VTL (no tag library support as first) we looked at Freemarker

It has all the advantages, but I wonder if this is as good as it gets

The other alternatives are eclipse JET, and I don't know of anything else at the moment

I would like a solution that can have Java content assist (like JSP) but that can be saved in the database

Is there something like this out there? (Besides JET, and JBoss's Freemarker buggy plugin)

Answer 1

Check out Thymeleaf .

I haven't used it.. YET!

It appears the developer designed it to address the shortcomings of Velocity and FreeMaker.

Answer 2

I have successfully used FreeMarker on several projects.

To address your concerns:

• Processing a template - even one written by a user - is secure if you don't expose any unsafe method in your model. In general, the model should only contain immutable objects (eg Strings, numbers) and collections of those (eg List, Map), and not be related in any way to the control layer of your MVC application.
• FreeMarker is simple enough for programmers, but not necessarily for web designers or editors.
• FreeMarker templates can be stored anywhere you like, since the template loader can be anything you can imagine. Have a look at the API documentation.
• FreeMarker templates are confined to the view layer of your MVC application, as long as you don't publish any sensible method in your model (see first point). Unlike JSP, they are completely unaware of the Servlet API.

As for content assist, most major IDE's (IntelliJ, Eclipse, probably NetBeans) have support for the FreeMarker syntax and should provide auto-completion for the keywords. If you want a JavaScript-based editor for FreeMarker, I'm not as affirmative since I know of none.

Good luck!