Class AbstractClassNameCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public final class AbstractClassNameCheck
    extends AbstractCheck

    Ensures that the names of abstract classes conforming to some pattern and check that abstract modifier exists.

    Rationale: Abstract classes are convenience base class implementations of interfaces, not types as such. As such they should be named to indicate this. Also if names of classes starts with 'Abstract' it's very convenient that they will have abstract modifier.

    • Property format - Specify valid identifiers. Type is java.util.regex.Pattern. Default value is "^Abstract.+$".
    • Property ignoreModifier - Control whether to ignore checking for the abstract modifier on classes that match the name. Type is boolean. Default value is false.
    • Property ignoreName - Control whether to ignore checking the name. Realistically only useful if using the check to identify that match name and do not have the abstract modifier. Type is boolean. Default value is false.

    To configure the check:

     <module name="AbstractClassName"/>
     

    Example:

     abstract class AbstractFirstClass {} // OK
     abstract class SecondClass {} // violation, it should match pattern "^Abstract.+$"
     class AbstractThirdClass {} // violation, must be declared 'abstract'
     class FourthClass {} // OK
     

    To configure the check so that it check name but ignore abstract modifier:

     <module name="AbstractClassName">
       <property name="ignoreModifier" value="true"/>
     </module>
     

    Example:

     abstract class AbstractFirstClass {} // OK
     abstract class SecondClass {} // violation, it should match pattern "^Abstract.+$"
     class AbstractThirdClass {} // OK, no "abstract" modifier
     class FourthClass {} // OK
     

    To configure the check to ignore name validation when class declared as 'abstract'

     <module name="AbstractClassName">
       <property name="ignoreName" value="true"/>
     </module>
     

    Example:

     abstract class AbstractFirstClass {} // OK
     abstract class SecondClass {} // OK, name validation is ignored
     class AbstractThirdClass {} // violation, must be declared as 'abstract'
     class FourthClass {} // OK, no "abstract" modifier
     

    To configure the check with format:

     <module name="AbstractClassName">
       <property name="format" value="^Generator.+$"/>
     </module>
     

    Example:

     abstract class GeneratorFirstClass {} // OK
     abstract class SecondClass {} // violation, must match pattern '^Generator.+$'
     class GeneratorThirdClass {} // violation, must be declared 'abstract'
     class FourthClass {} // OK, no "abstract" modifier
     

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • illegal.abstract.class.name
    • no.abstract.class.modifier
    Since:
    3.2
    • Field Detail

      • ignoreModifier

        private boolean ignoreModifier
        Control whether to ignore checking for the abstract modifier on classes that match the name.
      • ignoreName

        private boolean ignoreName
        Control whether to ignore checking the name. Realistically only useful if using the check to identify that match name and do not have the abstract modifier.
    • Method Detail

      • setIgnoreModifier

        public void setIgnoreModifier​(boolean value)
        Setter to control whether to ignore checking for the abstract modifier on classes that match the name.
        Parameters:
        value - new value
      • setIgnoreName

        public void setIgnoreName​(boolean value)
        Setter to control whether to ignore checking the name. Realistically only useful if using the check to identify that match name and do not have the abstract modifier.
        Parameters:
        value - new value.
      • setFormat

        public void setFormat​(Pattern pattern)
        Setter to specify valid identifiers.
        Parameters:
        pattern - the new pattern
      • 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
      • visitClassDef

        private void visitClassDef​(DetailAST ast)
        Checks class definition.
        Parameters:
        ast - class definition for check.
      • isAbstract

        private static boolean isAbstract​(DetailAST ast)
        Checks if declared class is abstract or not.
        Parameters:
        ast - class definition for check.
        Returns:
        true if a given class declared as abstract.
      • isMatchingClassName

        private boolean isMatchingClassName​(String className)
        Returns true if class name matches format of abstract class names.
        Parameters:
        className - class name for check.
        Returns:
        true if class name matches format of abstract class names.