This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Hola, I have JDK 1.4 installed and it works just fine. However, I want to take advantage of the new features given in 1.5. Do I have to first uninstall 1.4 and then install 1.5 or can all that be accomplished with a single upgrade step... Thanks,
Just install 1.5 and change your JAVA_HOME environment setting. You may also have to remove java.exe and javaw.exe from your windows directory (you'll have to do this if your path now says jdk1.5.0 yet java -version reports 1.4, or alternatively you get a classfile version error (49 found, 48 required) when running a freshly compiled class).
If you had 1.4 installed properly, that should be all you need to do.
You don't have to uninstall JDK 1.4. Just be sure to install JDK 1.5 in a different directory (folder) and change any related system variables (such as PATH and JAVA_HOME) to point to the new installation. This will make it so you can easily go back to 1.4 if necessary. Of course, once you are completely converted over to 1.5, you may then decide to uninstall 1.4.
Thank you Layne... indeed, it is not necessary to uninstall 1.4 in order to use new features of 1.5. Simple change of the PATH enviromental variable value after instalation of new JDK does it... but also the JAVA_HOME was mentioned. Where do I find it and to what do I change? I don't remember even declaring it while installing 1.4... OS is WinXP home edition...
Joined: Dec 06, 2001
Don't worry about JAVA_HOME. It is occassionally used by programming tools like the NetBeans IDE. If you haven't set it previously, then you probably don't need it atm.