Package com.puppycrawl.tools.checkstyle.checks.design

Class MutableExceptionCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public final class MutableExceptionCheck
extends AbstractCheck

    Ensures that exceptions (classes with names conforming to some regular expression and explicitly extending classes with names conforming to other regular expression) are immutable. That is, they have only final fields.

    Rationale: Exception instances should represent an error condition. Having non final fields not only allows the state to be modified by accident and therefore mask the original condition but also allows developers to accidentally forget to initialise state thereby leading to code catching the exception to draw incorrect conclusions based on the state.

    • Field Detail

      • MSG_KEY

        public static final java.lang.String MSG_KEY
        A key is pointing to the warning message text in "messages.properties" file.
        See Also:
        Constant Field Values

      • DEFAULT_FORMAT

        private static final java.lang.String DEFAULT_FORMAT
        Default value for format and extendedClassNameFormat properties.
        See Also:
        Constant Field Values

      • checkingStack

        private final java.util.Deque<java.lang.Boolean> checkingStack
        Stack of checking information for classes.

      • extendedClassNameFormat

        private java.util.regex.Pattern extendedClassNameFormat
        Pattern for class name that is being extended.

      • checking

        private boolean checking
        Should we check current class or not.

      • format

        private java.util.regex.Pattern format
        The regexp to match against.

    • Constructor Detail

      • MutableExceptionCheck

        public MutableExceptionCheck()

    • Method Detail

      • setExtendedClassNameFormat

        public void setExtendedClassNameFormat​(java.util.regex.Pattern extendedClassNameFormat)
        Sets the format of extended class name to the specified regular expression.
        Parameters:
        extendedClassNameFormat - a String value

      • setFormat

        public void setFormat​(java.util.regex.Pattern pattern)
        Set the format for the specified regular expression.
        Parameters:
        pattern - the new pattern

      • getDefaultTokens

        public int[] getDefaultTokens()
        Description copied from class: AbstractCheck
        Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.
        Specified by:
        getDefaultTokens in class AbstractCheck
        Returns:
        the default tokens
        See Also:
        TokenTypes

      • getRequiredTokens

        public int[] getRequiredTokens()
        Description copied from class: AbstractCheck
        The tokens that this check must be registered for.
        Specified by:
        getRequiredTokens in class AbstractCheck
        Returns:
        the token set this must be registered for.
        See Also:
        TokenTypes

      • 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

      • leaveToken

        public void leaveToken​(DetailAST ast)
        Description copied from class: AbstractCheck
        Called after all the child nodes have been process.
        Overrides:
        leaveToken in class AbstractCheck
        Parameters:
        ast - the token leaving

      • visitClassDef

        private void visitClassDef​(DetailAST ast)
        Called when we start processing class definition.
        Parameters:
        ast - class definition node

      • leaveClassDef

        private void leaveClassDef()
        Called when we leave class definition.

      • visitVariableDef

        private void visitVariableDef​(DetailAST ast)
        Checks variable definition.
        Parameters:
        ast - variable def node for check

      • isNamedAsException

        private boolean isNamedAsException​(DetailAST ast)
        Checks that a class name conforms to specified format.
        Parameters:
        ast - class definition node
        Returns:
        true if a class name conforms to specified format

      • isExtendedClassNamedAsException

        private boolean isExtendedClassNamedAsException​(DetailAST ast)
        Checks that if extended class name conforms to specified format.
        Parameters:
        ast - class definition node
        Returns:
        true if extended class name conforms to specified format