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

Class ReturnCountCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public final class ReturnCountCheck
extends AbstractCheck
    Restricts the number of return statements in methods, constructors and lambda expressions. Ignores specified methods (equals by default).

    max property will only check returns in methods and lambdas that return a specific value (Ex: 'return 1;').

    maxForVoid property will only check returns in methods, constructors, and lambdas that have no return type (IE 'return;'). It will only count visible return statements. Return statements not normally written, but implied, at the end of the method/constructor definition will not be taken into account. To disallow "return;" in void return type methods, use a value of 0.

    Rationale: Too many return points can mean that code is attempting to do too much or may be difficult to understand.

    • Property format - Specify method names to ignore. Type is java.util.regex.Pattern. Default value is "^equals$".
    • Property max - Specify maximum allowed number of return statements in non-void methods/lambdas. Type is int. Default value is 2.
    • Property maxForVoid - Specify maximum allowed number of return statements in void methods/constructors/lambdas. Type is int. Default value is 1.
    • Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: CTOR_DEF, METHOD_DEF, LAMBDA.

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • return.count
    • return.countVoid
    Since:
    3.2

    • 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

      • setFormat

        public void setFormat​(Pattern pattern)
        Setter to specify method names to ignore.
        Parameters:
        pattern - a pattern.
        Since:
        3.4

      • setMax

        public void setMax​(int max)
        Setter to specify maximum allowed number of return statements in non-void methods/lambdas.
        Parameters:
        max - maximum allowed number of return statements.
        Since:
        3.2

      • setMaxForVoid

        public void setMaxForVoid​(int maxForVoid)
        Setter to specify maximum allowed number of return statements in void methods/constructors/lambdas.
        Parameters:
        maxForVoid - maximum allowed number of return statements for void methods.
        Since:
        6.19

      • beginTree

        public void beginTree​(DetailAST rootAST)
        Description copied from class: AbstractCheck
        Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
        Overrides:
        beginTree in class AbstractCheck
        Parameters:
        rootAST - the root of the tree

      • visitMethodDef

        private void visitMethodDef​(DetailAST ast)
        Creates new method context and places old one on the stack.
        Parameters:
        ast - method definition for check.

      • leave

        private void leave​(DetailAST ast)
        Checks number of return statements and restore previous context.
        Parameters:
        ast - node to leave.

      • visitLambda

        private void visitLambda()
        Creates new lambda context and places old one on the stack.

      • visitReturn

        private void visitReturn​(DetailAST ast)
        Examines the return statement and tells context about it.
        Parameters:
        ast - return statement to check.