Ho una piattaforma Java
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
Java HotSpot(TM) Server VM (build 1.5.0-b64, mixed mode)

Ed ho i seguenti codici sorgente nel package 'random': è un programmino semplice.

GR.java
package random;

public interface GR
{
public double genNext();
}
GRUnif01.java
package random;

public class GRUnif01 implements GR
{
private double seme;
private long alfa;
private double modulo;
private double last;

public class SeedException extends Exception
{
public SeedException () {}
public SeedException (String str) { super(str); }
}

public class LambdaException extends Exception
{
public LambdaException () {}
public LambdaException (String str) { super(str); }
}

public GRUnif01(double seed) throws SeedException
{
if (seed <= 0) throw new SeedException();
seme = seed;
alfa = 16807;
modulo = 2147483647;
last = seed;
}

public double genNext()
{
last = (alfa * last) % modulo;
return last/modulo;
}
}

GRUnif.java
package random;

public class GRUnif extends GRUnif01
{
private double a;
private double b;

public GRUnif (double seed, double limInf, double limSup) throws SeedException
{
super(seed);
a = limInf;
b = limSup;
}

public double genNext()
{
double random0l = super.genNext();
return a + random0l*(b - a);
}

}
e questo main, contenuto nella classe di prova:
package random;

public class prova
{
public static void main(String args[])
{
try{random.GRUnif grSeme;
grSeme = new GRUnif(1, 1, 999999999);
System.out.println(grSeme);
}catch (Exception e) {System.err.println(e);}
}
}
La compilazione va a buon fine, ma al tentativo di avviare il test... ecco cosa ottengo:

Exception in thread "main" java.lang.NoClassDefFoundError: prova (wrong name: random/prova)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java :620)
at java.security.SecureClassLoader.defineClass(Secure ClassLoader.java:124)
at java.net.URLClassLoader.defineClass(URLClassLoader .java:260)
at java.net.URLClassLoader.access$100(URLClassLoader. java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java: 195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 51)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:319)

Perché???

Grazie a chiunque sappia aiutarmi!
L.