I have some enterprise apps running on Java 1.4. They mostly invoke Stored Proces on DB, Parse XML files (Not too large files, at the most few megs), read/write from/to disk. We have a requirement where now we have to migrate these apps to Java 6(No code changes to be done at all). My questions:
- If I dont recompile my apps under Java 6 and just run them with it, will it work fine (I know they 'should'). But if somebody thinks other way round, could you kindly share your thoughts please?
- More important question is - Will it have any perfomance impact?. As in, App compiled on 1.4 and running on 1.6 vs App compiled and running on 1.6. Is 1.6 gonna do any bytecode optimization for the same old peace of code compared to 1.4?
@steve - Yes, running on 1.6 will def be faster. But will compilation on 1.4 or 1.6 make any difference?
@Kees - Yes, no code change is a kind of requirement (Sad but true!). Didnt know that for CPU bound processes might get perfromnace benefits to the order of 50%. Thanks for sharing that. Also, XML libraries are the ones I am really worried abt. I just think that over last few years, XML processing and transofrmation has become too messy. But I get your point.
Kees Jan Koster
Joined: Mar 31, 2009
Whoever set the "no code changes" requirement needs to be sacked. Java 1.5 is EOSL, let alone 1.4. You are *years* behind in code cleaning and starting to use the safer and more performant collections (to name one example). The person setting the requirement is just adding to the technological debt you guys are building up.