Pattern: To many throw statements
Issue: -
Restricts throw statements to a specified count (4 by default). Methods with Override or java.lang.Override annotation are skipped from validation as current class cannot change signature of these methods.
Rationale: Exceptions form part of a method's interface. Declaring a method to throw too many differently rooted exceptions makes exception handling onerous and leads to poor programming practices such as writing code like catch(Exception ex). 4 is the empirical value which is based on reports that we had for the ThrowsCountCheck over big projects such as OpenJDK. This check also forces developers to put exceptions into a hierarchy such that in the simplest case, only one type of exception need be checked for by a caller but any subclasses can be caught specifically if necessary. For more information on rules for the exceptions and their issues, see Effective Java: Programming Language Guide Second Edition by Joshua Bloch pages 264-273.
ignorePrivateMethods - allows to skip private methods as they do not cause problems for other classes.
To configure the check so that it doesn't allow more than two throws per method:
<module name="ThrowsCount">
<property name="max" value="2"/>
</module>To configure the check so that it doesn't skip private methods:
<module name="ThrowsCount">
<property name="ignorePrivateMethods" value="false"/>
</module>