Java: how to "restart" a static class? - static

Question

I have a static class (Foo) and a main class (Main)
See Main.java:
public class Main {
public static void main(String[] args) {
System.out.println(Foo.i); // 0
Foo.i++;
System.out.println(Foo.i); // 1
// restart Foo here
System.out.println(Foo.i); // 1 again...I need 0
}
}
See Foo.java:
public class Foo {
public static int i = 0;
}
Is there any way to restart or reset a static class?
Note: I need this because I'm testing a static class with jUnit and I need to clean parameters before second test.
EDIT
ALMOST SOLUTION:
Using StanMax answer, I can to this:
Main.java
public class Main {
public static void main(String[] args) throws Exception {
test();
test();
}
public static void test() throws Exception {
System.out.println("\ntest()");
MyClassLoader myClassLoader = new MyClassLoader();
Class<?> fooClass = myClassLoader.loadClass(Foo.class.getCanonicalName());
Object foo = fooClass.newInstance();
System.out.println("Checking classloader: " + foo.getClass().getClassLoader());
System.out.println("GC called!");
System.gc();
}
}
MyClassLoader.java
public class MyClassLoader {
private URLClassLoader urlClassLoader;
public MyClassLoader() {
try {
URL url = new File(System.getProperty("user.dir") + "/bin/").toURL();
URL[] urlArray = {url};
urlClassLoader = new URLClassLoader(urlArray, null);
} catch (Exception e) {
}
}
public Class<?> loadClass(String name) {
try {
return (Class<?>) urlClassLoader.loadClass(name);
} catch (Exception e) {
}
return null;
}
#Override
protected void finalize() throws Throwable {
System.out.println("MyClassLoader - End.");
}
}
Foo.java
public class Foo {
public static int i = 0;
static {
System.out.println("Foo - BEGIN ---------------------------------");
}
public void finalize() throws Throwable {
System.out.println("Foo - End.");
}
}
OUTPUT
test()
Foo - BEGIN ---------------------------------
Checking classloader: java.net.URLClassLoader#ec160c9
GC called!
MyClassLoader - End.
Foo - End.
test()
Foo - BEGIN ---------------------------------
Checking classloader: java.net.URLClassLoader#ec3fb9b
GC called!
MyClassLoader - End.
Foo - End.
PROBLEM: if I do the cast bellow:
Foo foo = (Foo) fooClass.newInstance();
I get error:
java.lang.ClassCastException

Answer 1

Only if you can unload class, get it re-loaded, as class static code gets executed when class is loaded.
But you can just directly modify the value:
Foo.i = 0;
(or create equivalent method for doing it, esp. if static member is not public)

Answer 2

Create a static method that sets the class variables to their initial values, then call it when you need it.

Answer 3

Avoid static.
It is well known that static is not testable and should thus be avoided. For example, avoiding static is one of the key motivations behind dependency injection. If you need one instance only at runtime, use the singleton pattern instead. And create a new instance for each test run.

Answer 4

You can try this.
Main MainObject = new Main;
MainObject.main(args);
It will restart the class again and again until you stop the class.