Package com.puppycrawl.tools.checkstyle.checks.naming

Class LocalFinalVariableNameCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public class LocalFinalVariableNameCheck
extends AbstractNameCheck

    Checks that local final variable names conform to a specified pattern. A catch parameter and resources in try statements are considered to be a local, final variables.

    • Property format - Specifies valid identifiers. Type is java.util.regex.Pattern. Default value is "^[a-z][a-zA-Z0-9]*$".
    • Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: VARIABLE_DEF, PARAMETER_DEF, RESOURCE.

    To configure the check: 

     <module name="LocalFinalVariableName"/>

    An example of how to configure the check for names that are only upper case letters and digits is: 

     <module name="LocalFinalVariableName">
   <property name="format" value="^[A-Z][A-Z0-9]*$"/>
 </module>

    Code Example:

     class MyClass {
   void MyMethod() {
     try {
       final int VAR1 = 5; // OK
       final int var1 = 10; // violation,  name 'var1' must match pattern "^[A-Z][A-Z0-9]*$"
     } catch (Exception ex) {
       final int VAR2 = 15; // OK
       final int var2 = 20; // violation,  name 'var2' must match pattern "^[A-Z][A-Z0-9]*$"
     }
   }
 }

    An example of how to configure the check for names of local final parameters and resources in try statements (without checks on variables): 

     <module name="LocalFinalVariableName">
   <property name="format" value="^[A-Z][A-Z0-9]*$"/>
   <property name="tokens" value="PARAMETER_DEF,RESOURCE"/>
 </module>

    Code Example:

     class MyClass {
   void MyMethod() {
     try(Scanner scanner = new Scanner()) { // violation, name 'scanner' must
                                            // match pattern '^[A-Z][A-Z0-9]*$'
       final int VAR1 = 5; // OK
       final int var1 = 10; // OK
     } catch (final Exception ex) { // violation, name 'ex'
                                    // must match pattern '^[A-Z][A-Z0-9]*$'
       final int VAR2 = 15; // OK
       final int var2 = 20; // OK
     }
   }
 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • name.invalidPattern
    Since:
    3.0

    • Constructor Detail

      • LocalFinalVariableNameCheck

        public LocalFinalVariableNameCheck()
        Creates a new LocalFinalVariableNameCheck instance.

    • 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

      • mustCheckName

        protected final boolean mustCheckName​(DetailAST ast)
        Description copied from class: AbstractNameCheck
        Decides whether the name of an AST should be checked against the format regexp.
        Specified by:
        mustCheckName in class AbstractNameCheck
        Parameters:
        ast - the AST to check.
        Returns:
        true if the IDENT subnode of ast should be checked against the format regexp.