Class FinalParametersCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public class FinalParametersCheck
    extends AbstractCheck

    Checks that parameters for methods, constructors, catch and for-each blocks are final. Interface, abstract, and native methods are not checked: the final keyword does not make sense for interface, abstract, and native method parameters as there is no code that could modify the parameter.

    Rationale: Changing the value of parameters during the execution of the method's algorithm can be confusing and should be avoided. A great way to let the Java compiler prevent this coding style is to declare parameters final.

    • Property ignorePrimitiveTypes - Ignore primitive types as parameters. Type is boolean. Default value is false.
    • Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: METHOD_DEF, CTOR_DEF.

    To configure the check to enforce final parameters for methods and constructors:

     <module name="FinalParameters"/>
     

    To configure the check to enforce final parameters only for constructors:

     <module name="FinalParameters">
       <property name="tokens" value="CTOR_DEF"/>
     </module>
     

    To configure the check to allow ignoring primitive datatypes as parameters:

     <module name="FinalParameters">
       <property name="ignorePrimitiveTypes" value="true"/>
     </module>
     

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • final.parameter
    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

      • FinalParametersCheck

        public FinalParametersCheck()
    • Method Detail

      • setIgnorePrimitiveTypes

        public void setIgnorePrimitiveTypes​(boolean ignorePrimitiveTypes)
        Setter to ignore primitive types as parameters.
        Parameters:
        ignorePrimitiveTypes - true or false.
      • 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