Phantom Referenced Objects

Question

Phantom References serve for post-mortem operations. The Java specification states that a phantom referenced object will not be deallocated until the phantom-re

Answer 1

It can allow you two have phantom caches which are very efficient in memory management. Simply put, if you have huge objects that are expensive to create but seldom used, you can use a phantom cache to reference them and be sure they do not take up memory that is more valuable. If you use regular references you have to be manually make sure there are no references left to the object. You can argue the same about any object but you dont have to manually manage the references in your phantom cache. Just have to be carefull to check if they have been collected or not.

Also you can use a framework (i.e. a factory) where references are given as phantom references. This is useful if the objects are many and short lived (i.e. used and then disposed). Very handy for clearing memory if you have sloppy programmers that think garbage collection is magical.