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Native Class Amanuensis


This essay does not describe an existing computer program, just one that should exist. This essay is about a suggested student project in Java programming. This essay gives a rough overview of how it might work. I have no source, object, specifications, file layouts or anything else useful to implementing this project. Everything I have prepared to help you is right here.

This project outline is not like the artificial, tidy little problems you are spoon-fed in school, when all the facts you need are included, nothing extraneous is mentioned, the answer is fully specified, along with hints to nudge you toward a single expected canonical solution. This project is much more like the real world of messy problems where it is up to you to fully the define the end point, or a series of ever more difficult versions of this project and research the information yourself to solve them.

Everything I have to say to help you with this project is written below. I am not prepared to help you implement it; or give you any additional materials. I have too many other projects of my own.

Though I am a programmer by profession, I don’t do people’s homework for them. That just robs them of an education.

You have my full permission to implement this project in any way you please and to keep all the profits from your endeavour.

Please do not email me about this project without reading the disclaimer above.

This is one of the amanuensis projects. Let us say that you wanted to write a native class to access the volume serial number of a drive. This is just a couple of lines of assembler. However, to glue that code into Java would require a major intellectual effort. You would have to learn JNI (Java Native Interface) and Microsoft RNI (Raw Native Interface) and all the steps. 95% of what you read would be irrelevant to your tiny task. By the time you did another such project, it would all be a haze and you would have to start your earning from scratch.

I suggest writing an amanuensis that generates all the glue code, control files, headers etc. and a set of instructions on just what needs to be done manually.

You tell the Amanuensis the name of your native class, the methods and signatures, the native platforms you want to support and it generates all the necessary bubblegum, including some C and assembler skeleton programs that just access the parameters, create a dummy return value and return. They are heavily commented, so that most C or assembler programmers would be able to just look at those comments, flesh out the real code and go, without any understanding of JNI/RNI.

To start, pick just one platform, say Win95 and just JNI, and generate only the C skeleton. Design your classes so that you or others can plug in delegates later to handle other variants.

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