How to throw RuntimeException ("cannot find symbol")

Question

I'm trying to throw an exception in my code like this:

throw RuntimeException(msg); 

But when I build in NetBeans I get this error:

C:\....java:50: cannot find symbol symbol  : method RuntimeException(java.lang.String) location: class ...         throw RuntimeException(msg); 1 error 

Do I need to import something? Am I misspelling it? I'm sure I must be doing something dumb :-(

Answer 1

throw new RuntimeException(msg);

You need the new in there. It's creating an instance and throwing it, not calling a method.

Answer 2

An Exception is an Object like any other in Java. You need to use the new keyword to create a new Exception before you can throw it.

throw new RuntimeException(); 

Optionally you could also do the following:

RuntimeException e = new RuntimeException(); throw e; 

Both code snippets are equivalent.

Link to the tutorials for completeness.