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Automated Migration From Cobol To Java On Linux

Posted by timothy on from the so-kids-go-ahead-and-code-in-cobol dept.

Didier DURAND writes "Just published an article about our 100% automated migration from IBM mainframe with Cobol to Linux Java: we could convert of our own application (4 million lines of code) through the tools that we developed. Those tools are open-sourced under GPL for other companies to benefit from them. We save 3 millions euros / year after this migration!"

2 of 195 comments (clear)

  1. Re:"Automated" by filesiteguy · · Score: 3, Informative

    "sluggish java"??

    I've heard this misfound rumor time and again.

    Java - when properly written - has been proven to be as fast in file operations, memory access and sequential processing as true "compiled" applications.

    The same goes for other JIT languages such as .NET.

    --
    The Kai's Semi-Updated Website Thingy
  2. Re:mod parent up! by BikeHelmet · · Score: 3, Informative

    The JIT code is actually pretty fast. (especially when Hotspot is running in -server mode, which does some impressive optimization)

    It just consumes way too much memory, and starts damn slow. (though still faster than C#, in my experience)

    A couple times now I've taken base classes and rewritten them in Java to speed them up. ArrayList? Much too slow for my needs, even with a wrapper class ensurance it allocates in large enough chunks. By rewriting it in Java using Object arrays, I saw 60-100% speedups in the get/add methods, translating into roughly a ~2-4% speedup. (mileage may vary depending on workload)

    It was about 20000% faster than a default ArrayList - mind you, by default those things allocate in 6-index chunks, so every 6 objects you add it copies the whole ArrayList to a new one, with 6 more spots available. @_@

    There's a reason Java got the sluggish reputation, but it's not because the JIT code is slow. It's because the developers can get by with less of an understanding of what goes on behind the scenes, which never turns out good...