As the title says, is it possible? Right now, we have Java 6 + sqljdbc4 + glassfish 2.1.1. We're planning on upgrading our Java 6 to Java 8 in order for Sqljdbc42.jar to work, because we are having JDBC Connectivity issue and the solution might be to upgrade to sqljdbc42. Please see Option 1 in this link:
Of course some of you might say to upgrade Glassfish to a later version but in case is this is not an option, would errors occur? I found out that editing the asenv.bat will do the trick (http://alvinalexander.com/blog/post/java/fixing-glassfish-jdk-path-problem-solved) but I'm not sure about the deeper problems we might face.
Thank you so much for your answers.
You would have to be very brave (and have lots of free time) to try jdk-8 on glassfish-2. While you can still download glassfish-2, the Extended Support support ends this year (2017). This is not even Premium Support, it's Extended meaning you have already gone too far by this time. I know this because of a client I used to work for that used glassfish-2.
There were multiple bugs and complaints reported or the 3-rd and 4-th versions with jdk-8, not even speaking of 2-nd. Unfortunately you should upgrade to something way more recent (and have a constant plan to upgrade from there still). Obviously you can try and change the jdk version and see what happens - but I bet you would be visiting this site way more often than you would want to.
The real reason why you should seriously consider upgrading is that not a lot of people can answer deeper problems we might face, because not a lot of people use this version. Just my 0.02$.