Mon, 16 Mar 2009 15:46:46 +0000 (UTC), Nicholas Jordan wrote: > import placed in source file, will do a build later today as I am > swamped with simple survival stuff today. > > What I don't get is, given that javap pulls headers, I tried to use > the headers so that the JVM could call the dll. So far, so good, > except that it would be much more in the style intent and manner of D > to just write the calls and make the whole thing reliant on a header > style we are trying to get away from. > > Thus, I don't know how to prototype the function. There is JNIEnv / > jobject both of which resolve to "some computer stuff like we have > always known it" ... the JNIEnv is double indirection, jobject amounts > to something along the lines of a strongly typed pointer. > > If we could expose the function entry points to the JVM using D > syntax, I am sure the entry from the JVM would be 190% better. > > That is what my question actually is: "How do I expose the function > entry points to a running JVM - given that this code is called as a > loadable runtime?" > > I re-coded my def file several times, think I have got the entire > syntax starting to memorize. I put everything in there I could find in > the docs, have to recode the EXPORTS as on of the editors I tried ate > my sources last night. > > The massive array running down the middle is a bench hack as the > compiler kept complaining about how I was doing the pointers. That is > to be a data space some 1 to 100 kb by which I can pass data if I can > not get anything else to work. > > The intent is to write Java code, bring in an image using EZTwain, do > OCR on it.
I suggest you take an iterative approach. You're trying to make too many non-trivial things at once: learn D, make Java correctly interface with your DLL, make your DLL correctly interface with JRE, make your DLL correctly interface with TWAIN drivers. I suggest you create a very simple Java class, with a single native function taking an integer argument and returning its square, and implement this function in D. After this works, try adding another function, taking a string as an argument and returning another string. After you do that you'll have some grasp on D and on Java interfacing. Then you may try implementing one of your actual functions, but even then I suggest you skip TWAIN interactions first and fake them instead. Or try to write a simple console application doing exclusively TWAIN interactions. Currently, in your zarfOCR.d almost every single line requires fixing.
