In Java, how to convert Unchecked Exception into Checked Exception and Vice Versa in Java.
Add a comment
|
4 Answers
You can't convert. Rather you have to wrap into a new exception of the required type e.g. to convert to unchecked:
throw new RuntimeException(checkedException);
or to checked:
throw new Exception(uncheckedException);
(you may want to choose more meaningful/specific exception types)
3 Comments
Unihedron
Nice one, what if
checkedException is null? What happens?
Olaf Kock
when you're "converting" a checkedException, it's probably not null. Otherwise it would be NullpointerException, unchecked. Problem solved ;) (ducks)
Brian Agnew
If you catch an exception, it won't be null. I'm assuming the above would be used in a catch() clause
Unchecked Exceptions are subclasses of RuntimeException, checked ones are not. So to convert one exception you'd have to change its inheritance, then fix the compiler errors because your new checked exception was never declared or caught.
Comments
There is no way you can convert them. They are for different purposes. Caller needs to handle checked exceptions, while unchecked or runtime exceptions aren't usually taken care explicitly.
Comments
Let's say you've got two exception classes ExceptionA and ExceptionB; and one of them is checked and the other is unchecked. You want to convert ExceptionA to ExceptionB.
Assuming ExceptionB has a constructor like
public ExceptionB(Exception e) {
super(e);
}
you can do something like
catch (ExceptionA e) {
throw new ExceptionB(e);
}
to wrap objects of one exception class in the other.
answered Jul 25, 2014 at 10:12
Dawood ibn Kareem
80.2k15 gold badges102 silver badges112 bronze badges