UnsupportedClassVersionError (unsupported major.minor version 50.0)

[Krep Lock]

I've tried to install the JDK on my laptop and it's devolved into a horriffic timesink. I cannot get the simplest program to run:

//  test.java

public class test {

	public static void main(String[] args) {

		System.out.println("blah blah blah...");
	}

}

F:\Java\StartingOut\chapter2>javac test.java
F:\Java\StartingOut\chapter2>java test
Exception in thread "main" java.lang.UnsupportedClassVersionError: test (Unsuppo
rted major.minor version 50.0)
at java.lang.ClassLoader.defineClass0(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$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)

F:\Java\StartingOut\chapter2>SET CLASSPATH=

F:\Java\StartingOut\chapter2>javac test.java

F:\Java\StartingOut\chapter2>java test
Exception in thread "main" java.lang.UnsupportedClassVersionError: test (Unsuppo
rted major.minor version 50.0)
at java.lang.ClassLoader.defineClass0(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$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)

F:\Java\StartingOut\chapter2>javac -cp . test.java

F:\Java\StartingOut\chapter2>java -cp . test
Exception in thread "main" java.lang.UnsupportedClassVersionError: test (Unsuppo
rted major.minor version 50.0)
at java.lang.ClassLoader.defineClass0(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$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)

F:\Java\StartingOut\chapter2>

...so it's not likely to be CLASSPATH. I've tried installing that latest JDK/JRE, but nothing resolves this problem.

It's been a long time since I've done anything with Java; I've been working with other languages. Am I missing something simple here? Or am I going to have to resort to brain surgery on my laptop to fix some obscure setting or registry before this will work?

[Ernest Friedman-Hill]

You've got an extra copy of java.exe someplace on your path, from an older version of Java. You're therefore compiling with a new javac.exe which is generating class files that the old java.exe won't read.

It's probably in C:\WINDOWS or thereabouts. You can find it and delete it, or you can change your PATH to put your JDK bin directory first.

[Krep Lock]

Fixed!

Thanks very much. I'm glad I posted here instead of throwing my hands in the air and quitting.