Try to use reflection to open url in a webview,

I'm trying to use reflection for loadUrl in a webview, but it doesn't works.

I use this code :

Class primary
{..............
public void start(InputStream is) 
{

    prova = new _JsonRead();
    try {
        Class<?> test=Class.forName("xxx.test.learning.Webview1");
        Field f=test.getDeclaredField("myWebView");

        Class<?> web=WebView.class;
        Method metodo=web.getMethod("loadUrl",String.class); //restituisce il metodo loadUrl con parametro tipo stringa
         ; 
        metodo.invoke(f, "www.google.com");

    } catch (Exception e) {
        // TODO Auto-generated catch block
        Log.i("ecc", "error "+e);
        e.printStackTrace();
    }
.......
}
public class Webview1 extends Activity 
{
public WebView myWebView = null;
public WebSettings webSettings = null;

@Override
public void onCreate(Bundle SavedInstance)
{
    super.onCreate(SavedInstance);
    setContentView(R.layout.activity_webview);

    myWebView = (WebView) findViewById(R.id.webview);
    webSettings = myWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);

    Primary prova = new Primary();
    prova.start(getResources().openRawResource(R.raw.config));
    //myWebView.loadUrl(prova.indirizzo);

    /*
     * I move this function
     * myWebView.loadUrl("file:///android_asset/test.html");
     * in the Learning_lib2
     */

}

}

But there is this error : "03-01 15:58:07.200: I/ecc(19919): error java.lang.IllegalArgumentException: expected receiver of type android.webkit.WebView, but got java.lang.reflect.Field "

I'm new in reflection, and this is my first test. I have thought that Field was a generic Object , but securely I'm wronging..but where ? :/