Q:

Java or ABAP Web Dynpro? (SAP Web Development on Netweaver)

Are there any good arguments for using Java Web Dynpro over ABAP Web Dynpro? I've heard that the Java version is more mature by about 18 months because Dynpro was made for Java, and then ABAP devs wanted it once they saw it working.
I know ABAP is propriatary to SAP and the Java is much more widely used. Does this fact, plus the maturity of the Java version make it the best choice?
Also. should I even consider using the NWDI with Dynpro? NWDI seems like such a bad idea to me when I can use ANT for free. 

A:

Update( two years later): Now its official. Java Web Dynpro are put in maintenance mode. which mean that its will soon be only legacy technology. Right now( 2010) SAP is returning to abap only stack. I am not providing a link because sap links are short lived. Just search in http://sdn.sap.com.
Before update: There is no official sap position on this question as far as I know. So I will throw my two cents. First of all, I don't know of any good argument to use Java over ABAP in sap land.
It seems to me that new thing were developed in Java by Sap, because it was the "future". It looks like they actively hampered the development of the ABAP stack to give the Java stack a chance. But the only reason to use the SAP java application server is to access information and business logic on the ABAP application servers. There is no reason to use it by itself (as there are better j2ee alternatives). And even sap has not done any application of significance on the Java Application Server.
About the maturity. The webdynpro are more mature on the java stack. But the stack itself is terribly imature. 
It take more than ten minutes to start on a decent hardware.
The logging is scattered all over the place. With unusable gui. And very unfriendly to text viewer.
It is not using the java community resources for staff like version management and builds. And the SAP alternatives are imature.
About the availability of java programmers. That’s true, of course, but: Since most of the logic is in the abap stack ( in most scenarios ) there is a need to know both java and abap for any, more than trivial, application. And here you are dealing with a scarce resource. What happens is that you teach abap to java developer or vice versa. This is not bad but it is done from the wrong reasons. And you will have inexperience developers on the project ( inexperienced in one language stack).
Final word. If you care about usability of your site. Consider BSP or JSP. The webdynpro revive all the ugliness and un-usability that is in the Sapgui.

A:

I remember the instructor at my ABAP webdynpro class said that the ALV library was unavailable in the Java stack, so if you want the features it offers, like automatic excel exports and summation, you'd have to implement them yourself.

A:

Ask yourself why you'd consider WebDynpro to begin with.  Consider writing your own MVC (in ABAP or Java) an save yourself a good deal of headache of learning to paint yourself into an unusable WebDynpro corner.

