Package com.puppycrawl.tools.checkstyle.checks.coding

Class SimplifyBooleanExpressionCheck

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

    Checks for over-complicated boolean expressions. Currently finds code like if (b == true), b || true, !false, etc.

    Rationale: Complex boolean logic makes code hard to understand and maintain.

    To configure the check: 

     <module name="SimplifyBooleanExpression"/>

    Example:

     public class Test {

   public void bar() {

     boolean a, b;
     Foo c, d, e;

     if (!false) {}; // violation, can be simplified to true

     if (a == true) {}; // violation, can be simplified to a
     if (a == b) {}; // OK
     if (a == false) {}; // violation, can be simplified to !a
     if (!(a != true)) {}; // violation, can be simplified to a

     e = (a || b) ? c : d; // OK
     e = (a || false) ? c : d; // violation, can be simplified to a
     e = (a && b) ? c : d; // OK

  }

 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • simplify.expression
    Since:
    3.0

    • 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

    • Constructor Detail

      • SimplifyBooleanExpressionCheck

        public SimplifyBooleanExpressionCheck()

    • Method Detail

      • 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

      • 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

      • 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