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

Class PackageNameCheck

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

    Checks that package names conform to a specified pattern.

    The default value of format for module PackageName has been chosen to match the requirements in the Java Language specification and the Sun coding conventions. However both underscores and uppercase letters are rather uncommon, so most configurations should probably assign value ^[a-z]+(\.[a-z][a-z0-9]*)*$ to format for module PackageName.

    • Property format - Specifies valid identifiers. Type is java.util.regex.Pattern. Default value is "^[a-z]+(\.[a-zA-Z_][a-zA-Z0-9_]*)*$".

    To configure the check: 

     <module name="PackageName"/>

    Code Example:

     package com; // OK
 package COM; // violation, name 'COM' must match pattern '^[a-z]+(\.[a-zA-Z_][a-zA-Z0-9_]*)*$'
 package com.checkstyle.checks; // OK
 package com.A.checkstyle.checks; // OK
 package com.checkstyle1.checks; // OK
 package com.checkSTYLE.checks; // OK
 package com._checkstyle.checks_; // OK

    An example of how to configure the check to ensure with packages start with a lowercase letter and only contains lowercase letters or numbers is: 

     <module name="PackageName">
   <property name="format"
     value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
 </module>

    Code Example:

     package com; // OK
 package COM; // violation, name 'COM' must match pattern '^[a-z]+(\.[a-z][a-z0-9]*)*$'
 package com.checkstyle.checks; // OK
 package com.A.checkstyle.checks; // violation, name 'com.A.checkstyle' must match
                                  // pattern '^[a-z]+(\.[a-z][a-z0-9]*)*$'
 package com.checkstyle1.checks; // OK
 package com.checkSTYLE.checks; // violation, name 'com.checkSTYLE.checks' must
                                // match pattern '^[a-z]+(\.[a-z][a-z0-9]*)*$'
 package com._checkstyle.checks_; // violation, name 'com._checkstyle.checks_' must match
                                  // pattern '^[a-z]+(\.[a-z][a-z0-9]*)*$'

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • name.invalidPattern
    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

      • PackageNameCheck

        public PackageNameCheck()

    • Method Detail

      • setFormat

        public void setFormat​(java.util.regex.Pattern pattern)
        Setter to specifies valid identifiers.
        Parameters:
        pattern - the new pattern

      • 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