Correct me if I'm wrong but are you looking for a way to do something like

Code:
public class MyClass
{
   public void someMethod ()
   {
       TestObject myTestObject = new TestObject ();
   }
}
where new TestObject may be replaced by Spring, automagically returning a bean from the application context?

As irbouho said, that's not really possible without maybe using AOP to intercept the construction of TestObject. Your best bet is to have a some kind of factory which is injected into MyClass.

Code:
public class MyClass {
   TestObjectFactory toFactory;

   public void setFactory ( TestObjectFactory tof ) {
      toFactory = tof;
   }

   public void someMethod () {
       TestObject myTestObject = toFactory.newTestObject ();
   }
}
The factory can then decide how it wants to create/acquire a new TestObject instance. OK, it's one more class but it's still ignorant of Spring.

My experience is that maybe 85% of my classes have no knowledge of Spring but to harness the full power of Spring you need to use it's API, ideally only in your-own-framework classes.

Maybe you can give us an example of your ideal code and we'll try to help

Cuong.