UnsupportedClassVersionError due to java 7?

Question

Ok so I just finished an assignment for university and wanted to test my solution on their server and got this exception:

  [java] Exception in thread "main" java.lang.UnsupportedClassVersionError: controller/CloudController : Unsupported major.minor version 52.0
     [java]     at java.lang.ClassLoader.defineClass1(Native Method)
     [java]     at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
     [java]     at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
     [java]     at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
     [java]     at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
     [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
     [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
     [java]     at java.security.AccessController.doPrivileged(Native Method)
     [java]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
     [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
     [java]     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
     [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
     [java]     at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
     [java] Java Result: 1

I checked the server and found out they are using Java 7 while I used Java 8 already.

What I then tried was this:

enter image description here

I changed the Project language level to 7, but still this hasn`t solved the problem.

So here is my question, do I really have to download the 1.7 jdk to make this work, because I want to avoid this. The program has to run on the server though, since it is used for the grading and I obviously can`t update the Java version on an university server.

Thanks for any answers in advance.

Yes. Download JDK7 compile your classes with 7 .. – SMA Jan 04 '15 at 14:36 — SMA, Jan 04 '15 at 14:36

Todd · Accepted Answer · 2015-01-04T14:47:32.180

10

No, you shouldn't need to download JDK 7. This is a project level setting. Here is how I do it on IntelliJ IDEA 14, but I suspect it is the same if you are on 13 or 12.

Go to Settings->Build,Execution,Deployment->Compiler->Java Compiler. Under that tab you should see a Project-wide setting for Project Bytecode Version. Set that to 1.7 and you should be set.

enter image description here

You can also set the per-module settings here if for some reason you have some modules on one version and other modules on another version (but it doesn't sound like you do in this case).

edited Jan 04 '15 at 14:47

answered Jan 04 '15 at 14:41

Todd

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Thanks! and even easier solution was to remove the build folder and compile the files on the server LOL – Jakob Abfalter Jan 04 '15 at 15:00
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Also remember to modify the JRE version in Settings->Build,Execution,Deployment->Build Tools->Maven->Runner if you are using the Maven Lifecycle install – eureka19 Apr 17 '18 at 11:26

UnsupportedClassVersionError due to java 7?

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