How to loop through URLs with Interpreted Java? (again)

I'll start with a disclaimer that I recognize that I'm not a programmer (writing simple PHP code and Excel macros is about my speed) and therefore probably out of my depth; and that I'm probably posing a question that amounts to asking you to teach me how to program in Java.

However, I have a question which I've seen asked in several other forum posts, which seems to have confused more than just a few potential users, and which I still haven't been able to piece together after going through all the support materials: how do you write a script(s) to loop through incrementing a URL token in order to scrape multiple pages?

I'm talking about a scenario like scraping a page that is called with a URL like http://www.example.com/display.php?item=123 (or, for that matter, like http://www.screen-scraper.com/forum/phpBB2/viewtopic.php?t=324)

I can successfully follow the tutorial directions to generate a proxy session, define a scraping session and add a scrapeable file. I even get how to setup extractor patterns and write out the results of extraction to a file.

I have inserted a token into the URL as a placeholder for the item id (so the URL in the scrapeable file properties page becomes, for example, http://www.example.com/display.php?~#ITEM_ID#~.

Then, based upon one of the examples, I specified this "start session" script - which only successfully generates a scrape based upon the initial ITEM_ID = 601 and then terminates:

runnableScrapingSession = new com.screenscraper.scraper.RunnableScrapingSession( "item description" );

for(i=600; i<=650; i++)
{
runnableScrapingSession.setVariable("ITEM_ID", String.valueOf(i));
runnableScrapingSession.scrape();
}

Clearly I don't know what I'm doing... Help!

What I'd like is to setup a loop for the ITEM_ID token in the URL to be replaced during each successive iteration with the next number in sequence and have the scraping session re-run with that next ITEM_ID (in my example, for all the id's between 600 and 650).

The general flow, I believe, is something like this:

1. Initiate the scraping session (I'm doing this via a "start session" style script from the GUI as in the Tutorials)
2. Define a variable in the session to hold the ITEM_ID value
3. Define an initial value for ITEM_ID and a stopping value
4. Call the scrapeable file using the initial value of ITEM_ID
5. Scrape the scrapeable file
6. After file is scraped, write the results of extracting out to a file
7. increment the value of ITEM_ID
8. Call scrapeable file again with new (i.e. next) value of ITEM_ID in the URL

I've seen the post about how it is possible to setup an external batch file to invoke SS and feed it ITEM_ID's via "params" â€" but I'd like to learn how to do it with a loop using Interpreted Java.

As an aside, I (obviously!) think this would be a good topic for a dedicated tutorial â€" and sorry for the really long post and for revisiting a question that seems to have been asked before. I'd appreciate it if someone would take one more shot at explaining it step-by-step to someone who really wants to understand it but has met his match.