Class AvoidStaticImportCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public class AvoidStaticImportCheck
    extends AbstractCheck

    Check that finds static imports.

    Rationale: Importing static members can lead to naming conflicts between class' members. It may lead to poor code readability since it may no longer be clear what class a member resides (without looking at the import statement).

    An example of how to configure the check is:

     <module name="AvoidStaticImport">
       <property name="excludes"
           value="java.lang.System.out,java.lang.Math.*"/>
     </module>
     
    The optional "excludes" property allows for certain classes via a star notation to be excluded such as java.lang.Math.* or specific static members to be excluded like java.lang.System.out for a variable or java.lang.Math.random for a method.

    If you exclude a starred import on a class this automatically excludes each member individually.

    For example: Excluding java.lang.Math.* will allow the import of each static member in the Math class individually like java.lang.Math.PI

    • 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
      • excludes

        private java.lang.String[] excludes
        The classes/static members to exempt from this check.
    • Constructor Detail

      • AvoidStaticImportCheck

        public AvoidStaticImportCheck()
    • 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
      • setExcludes

        public void setExcludes​(java.lang.String... excludes)
        Sets the list of classes or static members to be exempt from the check.
        Parameters:
        excludes - a list of fully-qualified class names/specific static members where static imports are ok
      • isExempt

        private boolean isExempt​(java.lang.String classOrStaticMember)
        Checks if a class or static member is exempt from known excludes.
        Parameters:
        classOrStaticMember - the class or static member
        Returns:
        true if except false if not
      • isStarImportOfPackage

        private static boolean isStarImportOfPackage​(java.lang.String classOrStaticMember,
                                                     java.lang.String exclude)
        Returns true if classOrStaticMember is a starred name of package, not just member name.
        Parameters:
        classOrStaticMember - - full name of member
        exclude - - current exclusion
        Returns:
        true if member in exclusion list