Class SuppressWarningsCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public class SuppressWarningsCheck
    extends AbstractCheck

    Allows to specify what warnings that @SuppressWarnings is not allowed to suppress. You can also specify a list of TokenTypes that the configured warning(s) cannot be suppressed on.

    Limitations: This check does not consider conditionals inside the @SuppressWarnings annotation.

    For example: @SuppressWarnings((false) ? (true) ? "unchecked" : "foo" : "unused"). According to the above example, the "unused" warning is being suppressed not the "unchecked" or "foo" warnings. All of these warnings will be considered and matched against regardless of what the conditional evaluates to. The check also does not support code like @SuppressWarnings("un" + "used"), @SuppressWarnings((String) "unused") or @SuppressWarnings({('u' + (char)'n') + (""+("used" + (String)"")),}).

    By default, any warning specified will be disallowed on all legal TokenTypes unless otherwise specified via the tokens property.

    Also, by default warnings that are empty strings or all whitespace (regex: ^$|^\s+$) are flagged. By specifying, the format property these defaults no longer apply.

    This check can be configured so that the "unchecked" and "unused" warnings cannot be suppressed on anything but variable and parameter declarations. See below of an example.

    To configure the check:

     <module name="SuppressWarnings"/>

    To configure the check so that the "unchecked" and "unused" warnings cannot be suppressed on anything but variable and parameter declarations.

     <module name="SuppressWarnings">
       <property name="format"
       <property name="tokens"

    Parent is

    Violation Message Keys:

    • suppressed.warning.not.allowed
    • Method Detail

      • setFormat

        public final void setFormat​(Pattern pattern)
        Setter to specify the RegExp to match against warnings. Any warning being suppressed matching this pattern will be flagged.
        pattern - the new pattern
      • getAcceptableTokens

        public final 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
        the token set this check is designed for.
        See Also:
      • logMatch

        private void logMatch​(DetailAST ast,
                              String warningText)
        This method looks for a warning that matches a configured expression. If found it logs a violation at the given AST.
        ast - the location to place the violation
        warningText - the warning.
      • findWarningsHolder

        private static DetailAST findWarningsHolder​(DetailAST annotation)
        Find the parent (holder) of the of the warnings (Expr).
        annotation - the annotation
        a Token representing the expr.
      • removeQuotes

        private static String removeQuotes​(String warning)
        Strips a single double quote from the front and back of a string.

        For example:

         Input String = "unchecked"
        Output String = unchecked
        warning - the warning string
        the string without two quotes
      • walkConditional

        private void walkConditional​(DetailAST cond)
        Recursively walks a conditional expression checking the left and right sides, checking for matches and logging violations.
        cond - a Conditional type QUESTION
      • getCondLeft

        private static DetailAST getCondLeft​(DetailAST cond)
        Retrieves the left side of a conditional.
        cond - cond a conditional type QUESTION
        either the value or another conditional
      • getCondRight

        private static DetailAST getCondRight​(DetailAST cond)
        Retrieves the right side of a conditional.
        cond - a conditional type QUESTION
        either the value or another conditional