I can not launch my java application as a web applet in HTML (I am using HTML 4.01, I know it doesn't work in html5). The error message it returns is:
java : Unsupported major.minor version 52.0
I have tried downgrading my java JRE/JDK/SDK but I still get the same error message. The current version of java I am now using is 1.8.0_05.
I assumed openjdk8 would work with tomcat8 but I had to remove it and keep openjdk7 only, this fixed the issue in my case. I really don't know why or if there is something else I could have done.
I noticed that in netbeans Apache configuration in the servers tab. you can state the platform for your web application. I changed to 1.8 and it worked fine. (I am targeting java 8 platform in my application). Hope that might t help.
You have to compile with Java 1.7. But if you have *.jsp files, you should also completely remove Java 1.8 from the system. If you use Mac, here is how you can do it.
Source: Stackoverflow.com