This is a quick article I have had as a draft for quite a while. It might not be finished or have other problems, but I still want to share it.
When to use Errors and Exceptions
An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch. Most such errors are abnormal conditions.
(Source: Javadoc)
How to throw an exception
public void myMethod( String s ) {
if (!isStringValid(s)) {
throw new IllegalArgumentException("This string is not valid!");
}
}
Common Exceptions
- IllegalArgumentException: One argument of the current method doesn't have the form it should have.
- IllegalStateException: The current object is in the wrong state.
- NullPointerException: A null pointer was given, but it should have been an object.
A long list of exceptions is on Hai's Blog.