This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Is there any known repercussions to running Java 1.4 compiled apps under a 1.5 JVM (altering the JNLP to use 1.5)? We have run into an issue with clients running our 1.4 apps while using Windows 7 64 bit machines, the issue being it doesn't work. It does work with Java 5 32-bit JRE installed on the Windows 7 machine. Any thoughts would be greatly appreciated.
Maybe there are some JVM incompatibility with anothers architectures like from 32bits for 64bits, i don't know. But you could try search for flag configs to JVM to run it as 1.4 java code and maybe some flag to convert 32-64bits or something like that.
Feel free to ask me anything!
www.BlackBeltFactory.com/ui#!/ref=jmotta, SCJP 6, OCWCD JEE5, OCE EJB JEE6
Even so, i don't believe it could not work once "Write once, run everywhere" is what mess/bless us, what happens when you try to run the program? Try to execute this from the DOS and see what is returned, like an error or something like that!
You should be able to run Java 1.4 compiled apps on Java 5 without changing anything. Sun (and now Oracle) have always been very, very careful to make sure that newer Java versions are backwards compatible with older versions.
Thanks for the responses guys... the thing to mention i guess is the highest public version of Java 1.4.2 is Update 19, and this is not supported under Windows 7... not till Update 23 and that gets you into Java For Business which isn't free and is very costly... hence attempting to run our 1.4 apps under the 1.5 JVM.
Rob Spoor said "ItDoesntWorkIsUseless. What error are you getting, or what is it doing other than expected?" >>> i mean it does not work, nothing happens... this was with trying 1.4.2_19
On another note, we have been testing one of our simpler applications (reporting) and everything seems to be working as normal... the next will be our billing app which has more depth to it... my main concern was if anyone knew of any specific things that would not work by running this way.
Once again, thanks for everyone's time... much appreciated.
If you decide to upgrade to a newer version of Java, then I'd strongly recommend that you use Java 6, not Java 5 - because Java 5 is also very old and has been in the end-of-life status since October 2009 (see this page for more information).
Java 6 contains lots of improvements, not only in functionality but also in performance, compared to Java 5.