Java Exception after exporting runnable jar

Question

When I try to run the jar, after exporting it using eclipse, this is what I get:

Exception in thread "main" java.lang.UnsupportedClassVersionError: ietstesten : Unsupported major.minor version 52.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$100(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

I don't really know why this happens. I tried importing everything into a new project but it doesn't seem to solve anything.

When I double click the jar I get "Java Exception Occured"

possible duplicate of [Exception in thread "main" java.lang.UnsupportedClassVersionError, Unsupported major.minor version 52.0](http://stackoverflow.com/questions/18161907/exception-in-thread-main-java-lang-unsupportedclassversionerror-unsupported-m) — Kenster, Dec 18 '14 at 17:38

Bruce · Answer 1 · 2014-12-18T17:12:47.310

2

This happens because of your jar file compiled in java 1.8 But you are running in the lower version than 1.8

Install Java 8
Change compliance level to 1.8 in your IDE

Java Version History

J2SE 8 = 52

J2SE 7 = 51

J2SE 6.0 = 50

J2SE 5.0 = 49

JDK 1.4 = 48

JDK 1.3 = 47

JDK 1.2 = 46

JDK 1.1 = 45

edited Dec 18 '14 at 17:12

answered Dec 18 '14 at 17:06

Bruce

8,609
8
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I checked if I had the newest version, though, but thanks! Ill double check! – Jbv1 Dec 19 '14 at 01:16

score 0 · Answer 2 · answered Dec 18 '14 at 17:02

0

You get the version error when the Jar is compiled with a newer Java version than what you are using to run it with. Did you compile it with Java 8 and are you now running it with Java 7 perhaps?

answered Dec 18 '14 at 17:02

David ten Hove

2,748
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Java Exception after exporting runnable jar

2 Answers2

Java Version History