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Is Java the wrong language for a duplicate file scanner?

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Join Date: Dec 2008

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neilcoffey neilcoffey is offline

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Re: Is Java the wrong language for a duplicate file scanner?

#11

Jan 8th, 2009

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Originally Posted by ~s.o.s~

Re MD5: I guess we are talking about two different things here: security and file uniqueness, hence the confusion. I would personally use MD5 hashing since it seems to be a widely used technique for testing file uniqueness and optimize if and only if required.

And I'd say that's a fair enough way forward. The other advantage of MD5 is that Java gives it you "out of the box".

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Originally Posted by ~s.o.s~

Also, coming up with a good hash solution [if that is what you were suggesting to the OP] is far from a walk in the park, though it seems to be a good exercise in learning more about hash functions.

No, I was thinking the poster could just use a standard one. Numerical Recipes suggests one that I think would work reasonably well.

> Yep-- the OS will generally automatically cache data read from file.

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Originally Posted by ~s.o.s~

If you are talking about kernel file caching which results from reliance on system calls to do I/O, memory mapping the file solves that issue.

In my head, I suppose I was actually discounting mapping the file because in practice, Java has (or has had) some severe problems with this, such as not providing a wap to unmap a section of file once it is mapped, and imposing a less-than-expected limit on the total size of mapped file sections. However, if the poster can get things working with file mapping, I'd be very interested to know.

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jbennet

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Re: Is Java the wrong language for a duplicate file scanner?

#12

Jan 8th, 2009

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Originally Posted by BestJewSinceJC

Personally I would write this in C over Java. Only because Java is Object oriented and the problem you have posed isn't. Well sort of, but even more the fact that C will probably be much faster than Java for this project.

He wants it to be able to be run online in a web browser. Java can do that. C cant. He says

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Im also going to try and make it available online, a bit similar to online virus scanning websites. Ive got the website up in HTML, but im willing to scrap that if the duplicate file scanner cant be added to the website code as a plugin / object etc. Is java the wrong language, is netbeans not the best IDE? Shall I consider AJAX

Last edited by jbennet; Jan 8th, 2009 at 10:00 pm.

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