Returning value to use in variable

Returning value to use in variable

Having a bit of a problem, basically I've got a button setup to generate a
alphanumeric number which it does however I'm having trouble turning in to
a variable that I can implement into another.
final String image_url = ("" + rand + jpg);
final ImageLoader imgLoader = new
ImageLoader(getApplicationContext());
imgLoader.DisplayImage(image_url, loader, image);
Button bButton = (Button) findViewById(R.id.button1);
bButton.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
RandomString.generateRandomString(7,RandomString.Mode.ALPHANUMERIC);
imgLoader.DisplayImage(image_url, loader, image);
}
Basically I want
RandomString.generateRandomString(7,RandomString.Mode.ALPHANUMERIC);
to return a value that is 'stored' as 'rand' used in the final String
Image_url. Just to clarify the random generator works fine, I can set it
to a TextView and it works fine, I may be stupid but I'm a bit stuck with
this bit.