How to compile dynamic library for a JNI application on linux?

I'm using Ubuntu 10.10

So that's what I did.

Hello.java:

class Hello {
        public native void sayHello();

        static { System.loadLibrary("hellolib"); }

        public static void main(String[] args){
                Hello h = new Hello();
                h.sayHello();
        }
}

Then I ran the follwing commands:

dierre@cox:~/Scrivania/provajni$ javac Hello.java

dierre@cox:~/Scrivania/provajni$ javah -jni Hello 

I've obtained Hello.class and Hello.h.

Hello.h:

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class Hello */

#ifndef _Included_Hello
#define _Included_Hello
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     Hello
 * Method:    sayHello
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_Hello_sayHello
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

Then I created Hello.cpp:

#include <jni.h>
#include "Hello.h"
#include  <iostream>

using namespace std;

JNIEXPORT void JNICALL Java_Hello_sayHello (JNIEnv *env, jobject obj) {
        cout << "Hello World!" << endl;
        return;
}

And now the part where I think I screwed up. I was inspired by this guide (Compile the Dynamic or Shared Object Library section):

dierre@cox:~/Scrivania/provajni$ gcc -I"/usr/lib/jvm/java-6-sun/include" -I"/usr/lib/jvm/java-6-sun/include/linux" -o hellolib.so -shared -Wl,-soname,hello.so Hello.cpp -static -lc

that generates the file hellolib.so

But when I try to run it with java Hello I have this error:

Exception in thread "main" java.lang.UnsatisfiedLinkError: no hellolib in java.library.path
 at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1734)
 at java.lang.Runtime.loadLibrary0(Runtime.java:823)
 at java.lang.System.loadLibrary(System.java:1028)
 at Hello.<clinit>(Hello.java:4)
Could not find the main class: Hello.  Program will exit.

I even tried this:

  LD_LIBRARY_PATH=`pwd`
  export LD_LIBRARY_PATH

with no results.

I know I'm doing something extremely stupid but I can't figure out what it is. The dynamic lib is generated with the -shared option, isn't it?

Update #1

I tried static { System.load("/home/dierre/Scrivania/provajni/hellolib.so"); } to see if that worked but now:

Exception in thread "main" java.lang.UnsatisfiedLinkError: /home/dierre/Scrivania/provajni/hello.so: /home/dierre/Scrivania/provajni/hello.so: undefined symbol: _ZSt4cout
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1803)
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1699)
    at java.lang.Runtime.load0(Runtime.java:770)
    at java.lang.System.load(System.java:1003)
    at Hello.<clinit>(Hello.java:4)

Update #2 Ok, to solve the Update #1 problem I had to use g++ insted of gcc, obviously. Still having trouble to use the load method though. I can't seem to tell it the right path.