Class ThrowsCountCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public final class ThrowsCountCheck
    extends AbstractCheck

    Restricts throws statements to a specified count (default = 4). 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 methods interface. Declaring a method to throw too many differently rooted exceptions makes exception handling onerous and leads to poor programming practices such as catch (Exception). 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 allows any sub-classes to 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.

    Author:
    Simon Harris
    • Constructor Detail

      • ThrowsCountCheck

        public ThrowsCountCheck()
        Creates new instance of the check.
    • Method Detail

      • getAcceptableTokens

        public int[] getAcceptableTokens()
        Description copied from class: AbstractCheck
        The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.
        Specified by:
        getAcceptableTokens in class AbstractCheck
        Returns:
        the token set this check is designed for.
        See Also:
        TokenTypes
      • setIgnorePrivateMethods

        public void setIgnorePrivateMethods​(boolean ignorePrivateMethods)
        Sets whether private methods must be ignored.
        Parameters:
        ignorePrivateMethods - whether private methods must be ignored.
      • setMax

        public void setMax​(int max)
        Setter for max property.
        Parameters:
        max - maximum allowed throws statements.