> Not all. Some of them are related to execution environment of an application, not to your code Let's say "more or less all": Yes, if there's an OOM because t

> Not all. Some of them are related to execution environment of an application, not to your code Let's say "more or less all": Yes, if there's an OOM because the system has not enough memory at all you maybe have to tell the user what to do instead of just crashing because the environment failed you, but in almost every other case the moment you accept the environment as parameter it becomes part of your code: If someone gives you a null object you can throw an IllegalArgumentException and show the calling program that it misused your API, but if you accept null and then call some method without checking for null the NPE you get is your bug, not that of your caller. Edit: Rewritten to make my point clearer.