Why catch Exceptions in Java, when you can catch Throwables?

Question

We recently had a problem with a Java server application where the application was throwing Errors which were not caught because Error is a separate subclass of Throwable and we were only catching Exceptions.

We solved the immediate problem by catching Throwables rather than Exceptions, but this got me thinking as to why you would ever want to catch Exceptions, rather than Throwables, because you would then miss the Errors.

So, why would you want to catch Exceptions, when you can catch Throwables?

Answer 1

From the Java API documentation:

The class Exception and its subclasses are a form of Throwable that indicates conditions that a reasonable application might want to catch.

An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch.

Errors usually are low-level (eg., raised by the virtual machine) and should not be caught by the application since reasonable continuation might not be possible.