Class LineLengthCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public class LineLengthCheck
    extends AbstractCheck
    Checks for long lines.

    Rationale: Long lines are hard to read in printouts or if developers have limited screen space for the source code, e.g. if the IDE displays additional information like project tree, class hierarchy, etc.

    Package statements and import statements (lines matching pattern ^(package|import) .*), and are not verified by this check.

    The default maximum allowable line length is 80 characters. To change the maximum, set property max.

    To ignore lines in the check, set property ignorePattern to a regular expression for the lines to ignore.

    An example of how to configure the check is:

     <module name="LineLength"/>
     

    An example of how to configure the check to accept lines up to 120 characters long is:

     <module name="LineLength">
        <property name="max" value="120"/>
     </module>
     

    An example of how to configure the check to ignore lines that begin with " * ", followed by just one word, such as within a Javadoc comment, is:

     <module name="LineLength">
        <property name="ignorePattern" value="^ *\* *[^ ]+$"/>
     </module>
     
    • 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

      • LineLengthCheck

        public LineLengthCheck()
    • 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
      • beginTree

        public void beginTree​(DetailAST rootAST)
        Description copied from class: AbstractCheck
        Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
        Overrides:
        beginTree in class AbstractCheck
        Parameters:
        rootAST - the root of the tree
      • setMax

        public void setMax​(int length)
        Sets the maximum length of a line.
        Parameters:
        length - the maximum length of a line
      • setIgnorePattern

        public final void setIgnorePattern​(java.util.regex.Pattern pattern)
        Set the ignore pattern.
        Parameters:
        pattern - a pattern.