Persistent static

Question

Does anybody have a recommendation on good way to get the effect of a
persistent static object (ie. one persistent instance for all objects of a
persistent class)?
Scott

Answer 1

If you mean one shared PC instance, you can have a facade to store the
oid of that single object for use by each specific instance:
public class Foo
     private static Object oid = null;
     // ... persistent attributes here ...//
     public static Foo getSharedInstance (PersistenceManager pm)
          if (oid == null)
               Extent e = pm.getExtent (Foo.class, false);
               oid = JDOHelper.getObjectId
                    (e.iterator ().next ());
          return pm.getObjectById (false);
Of course this is untested, but you get the idea. Then in when you deal
with Bar instances sharing that Foo, you can simply do something along
the lines of
     Bar bar = new Bar ();
     bar.setFoo (Foo.getSharedInstance (pm));
Scott Leschke wrote:
Does anybody have a recommendation on good way to get the effect of a
persistent static object (ie. one persistent instance for all objects of a
persistent class)?
Scott
Stephen Kim
[email protected]
SolarMetric, Inc.
http://www.solarmetric.com