orDrumbox Java Software Drum Machine

Here is what I am seeing:

$ java -jar orDrumbox-0.6.02.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: ordrumbox/swing/Ihm (Unsupported major.minor version 49.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)

Any ideas?

java -version
java version "1.4.2-01"
Java(TM) 2 Runtime Environment, Standard Edition (build Blackdown-1.4.2-01)
Java HotSpot(TM) Client VM (build Blackdown-1.4.2-01, mixed mode)

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