HyperCon Ubuntu 14.04 not work :(

Hello! I am trying to launch Hyperion server on mini PC on ubuntu 13.04 according to the instructions here https://hyperion-project.org/wiki/HyperCon-Information
I run through the terminal:
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ubuntu@Mini-PC:~$ java -jar ./HyperCon.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/hyperion/hypercon/Main : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:808)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:443)
at java.net.URLClassLoader.access$100(URLClassLoader.java:65)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.net.URLClassLoader$1.run(URLClassLoader.java:349)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:348)
at java.lang.ClassLoader.loadClass(ClassLoader.java:430)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:323)
at java.lang.ClassLoader.loadClass(ClassLoader.java:363)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
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What to do? How to start?

Zitat von TPmodding

which java version do you have?
java -version

java version 1.7.0 51
Ubuntu 13.04
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tried the instruction steps https://hyperion-project.org/w…stallation-on-all-systems
Result on the photo

Zitat von TPmodding

just update your java...

I tried on another version of ubuntu 14.04 from Java 1.7.71
There is exactly the same mistake!

Zitat von TPmodding

from google:

sudo apt-get install openjdk-8-jre

sudo update-alternatives --config java
and then select java8

userl@host-424248691:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 13.04
Release: 13.04
Codename: raring
userl@host-424248691:~$ sudo apt-get install openjdk-8-jre
[sudo] password for userl:
Reading package lists ... Done
Building a dependency tree
Reading status information ... Done
E: Could not find package openjdk-8-jre
userl@host-424248691:~$ sudo update-alternatives --config java
There is only one alternative in the java link group (providing /usr/bin/java): /usr/lib/jvm/java-7-openjdk-armhf/jre/bin/java
There is nothing to adjust.

:(((((