title: How do I save objects/instances while running a jar-file?
body: <p>I've created a little program with <em>BlueJ</em> that works as a digital registry (registry as in 'a sorted list'). The program has only two classes: one working as a template for the entries in the registry which in return is represented by an <strong>ArrayList</strong> in the second class, the one managing all entries. E.g. the user can create a new entry via the console and later search for the right entry and read the details over the console, thus this entries are <strong>instances</strong> of the first class "Entry".</p>
  
  <p>Now I've exported the .<strong>jar</strong> and I do can use all features as in the console-simulation but since the instances aren't saved actually but rather for only one <em>session</em> this program has no useful functionality. I somehow need to save those created instanced in order to have them <em>already in the ArrayList</em> everytime I run the program.
  I'm searching for something that does like the "<strong>save world</strong>" functionality does in <em>Greenfoot</em>.</p>
  
  <p>I've read that you can save objects with the help of the testclass in BlueJ: <a href="http://freebluej.blogspot.de/2008/09/saving-objects.html" rel="nofollow">Saving Objects with the testclass</a>. But the problem is that I can't actually "see" those entries since they are stored in the ArrayList and that I later want to run the program completely independent (i.e. without BlueJ but the .jar).</p>
  
  <p>Does anybody know how I can <strong>save</strong> those instances and use them later on when I quit and run the program again?</p>