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

Class ConstantNameCheck

java.lang.Object
com.puppycrawl.tools.checkstyle.api.AutomaticBean
com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
com.puppycrawl.tools.checkstyle.api.AbstractCheck
com.puppycrawl.tools.checkstyle.checks.naming.AbstractNameCheck
com.puppycrawl.tools.checkstyle.checks.naming.AbstractAccessControlNameCheck
com.puppycrawl.tools.checkstyle.checks.naming.ConstantNameCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class ConstantNameCheck extends AbstractAccessControlNameCheck

Checks that constant names conform to a specified pattern. A constant is a static and final field or an interface/annotation field, except serialVersionUID and serialPersistentFields .

  • Property format - Specifies valid identifiers. Type is java.util.regex.Pattern. Default value is "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$".
  • Property applyToPublic - Controls whether to apply the check to public member. Type is boolean. Default value is true.
  • Property applyToProtected - Controls whether to apply the check to protected member. Type is boolean. Default value is true.
  • Property applyToPackage - Controls whether to apply the check to package-private member. Type is boolean. Default value is true.
  • Property applyToPrivate - Controls whether to apply the check to private member. Type is boolean. Default value is true.

To configure the check: 

 <module name="ConstantName"/>

Example:

 class MyClass {
   public final static int FIRST_CONSTANT1 = 10; // OK
   protected final static int SECOND_CONSTANT2 = 100; // OK
   final static int third_Constant3 = 1000; // violation, name 'third_Constant3' must
                                           // match pattern '^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
   private final static int fourth_Const4 = 50; // violation, name 'fourth_Const4' must match
                                                 // pattern '^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
 }

The following configuration apart from names allowed by default allows log or logger: 

 <module name="ConstantName">
   <property name="format"
     value="^log(ger)?$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$"/>
 </module>

Code Example:

 class MyClass {
   final static int log = 10; // OK
   final static int logger = 50; // OK
   final static int logMYSELF = 10; // violation, name 'logMYSELF' must match
                                    // pattern '^log(ger)?$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
   final static int loggerMYSELF = 5; // violation, name 'loggerMYSELF' must match
                                      // pattern '^log(ger)?$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
   final static int MYSELF = 100; // OK
   final static int myselfConstant = 1; // violation, name 'myselfConstant' must match pattern
                                        // '^log(ger)?$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
 }

The following configuration skip validation on public constant field and protected constant field. 

 <module name="ConstantName">
   <property name="applyToPublic" value="false"/>
   <property name="applyToProtected" value="false"/>
 </module>

Code Example:

 class MyClass {
   public final static int firstConstant = 10; // OK
   protected final static int secondConstant = 100; // OK
   final static int thirdConstant = 1000; // violation, name 'thirdConstant' must
                                          // match pattern '^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
   private final static int fourthConstant = 50; // violation, name 'fourthConstant' must match
                                                 // pattern '^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$'
 }

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • name.invalidPattern
Since:
3.0

  • Constructor Details

    • ConstantNameCheck

      public ConstantNameCheck()
      Creates a new ConstantNameCheck instance.

  • Method Details

    • 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:

    • 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:

    • 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:

    • 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.
      Overrides:
      mustCheckName in class AbstractAccessControlNameCheck
      Parameters:
      ast - the AST to check.
      Returns:
      true if the IDENT subnode of ast should be checked against the format regexp.