Class SuppressWithNearbyCommentFilter

  • All Implemented Interfaces:
    Configurable, Contextualizable, TreeWalkerFilter

    public class SuppressWithNearbyCommentFilter
    extends AutomaticBean
    implements TreeWalkerFilter

    Filter SuppressWithNearbyCommentFilter uses nearby comments to suppress audit events.

    Rationale: Same as SuppressionCommentFilter. Whereas the SuppressionCommentFilter uses matched pairs of filters to turn on/off comment matching, SuppressWithNearbyCommentFilter uses single comments. This requires fewer lines to mark a region, and may be aesthetically preferable in some contexts.

    Attention: This filter may only be specified within the TreeWalker module (<module name="TreeWalker"/>) and only applies to checks which are also defined within this module. To filter non-TreeWalker checks like RegexpSingleline, a SuppressWithPlainTextCommentFilter or similar filter must be used.

    SuppressWithNearbyCommentFilter can suppress Checks that have Treewalker as parent module.

    • Property commentFormat - Specify comment pattern to trigger filter to begin suppression. Type is java.util.regex.Pattern. Default value is "SUPPRESS CHECKSTYLE (\w+)".
    • Property checkFormat - Specify check pattern to suppress. Type is java.util.regex.Pattern. Default value is ".*".
    • Property messageFormat - Define message pattern to suppress. Type is java.util.regex.Pattern. Default value is null.
    • Property idFormat - Specify check ID pattern to suppress. Type is java.util.regex.Pattern. Default value is null.
    • Property influenceFormat - Specify negative/zero/positive value that defines the number of lines preceding/at/following the suppression comment. Type is java.lang.String. Default value is "0".
    • Property checkCPP - Control whether to check C++ style comments (//). Type is boolean. Default value is true.
    • Property checkC - Control whether to check C style comments (/* ... */). Type is boolean. Default value is true.

    To configure a filter to suppress audit events for check on any line with a comment SUPPRESS CHECKSTYLE <i>check</i>:

     <module name="SuppressWithNearbyCommentFilter"/>
     
     private int [] array; // SUPPRESS CHECKSTYLE
     

    To configure a filter to suppress all audit events on any line containing the comment CHECKSTYLE IGNORE THIS LINE:

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat" value="CHECKSTYLE IGNORE THIS LINE"/>
       <property name="checkFormat" value=".*"/>
       <property name="influenceFormat" value="0"/>
     </module>
     
     public static final int lowerCaseConstant; // CHECKSTYLE IGNORE THIS LINE
     

    To configure a filter so that // OK to catch (Throwable|Exception|RuntimeException) here permits the current and previous line to avoid generating an IllegalCatch audit event:

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat" value="OK to catch (\w+) here"/>
       <property name="checkFormat" value="IllegalCatchCheck"/>
       <property name="messageFormat" value="$1"/>
       <property name="influenceFormat" value="-1"/>
     </module>
     
     . . .
     catch (RuntimeException re) {
     // OK to catch RuntimeException here
     }
     catch (Throwable th) { ... }
     . . .
     

    To configure a filter so that CHECKSTYLE IGNORE <i>check</i> FOR NEXT <i>var</i> LINES avoids triggering any audits for the given check for the current line and the next var lines (for a total of var+1 lines):

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat"
           value="CHECKSTYLE IGNORE (\w+) FOR NEXT (\d+) LINES"/>
       <property name="checkFormat" value="$1"/>
       <property name="influenceFormat" value="$2"/>
     </module>
     
     static final int lowerCaseConstant; // CHECKSTYLE IGNORE ConstantNameCheck FOR NEXT 3 LINES
     static final int lowerCaseConstant1;
     static final int lowerCaseConstant2;
     static final int lowerCaseConstant3;
     static final int lowerCaseConstant4; // will warn here
     

    To configure a filter to avoid any audits on code like:

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat"
         value="ALLOW (\\w+) ON PREVIOUS LINE"/>
       <property name="checkFormat" value="$1"/>
       <property name="influenceFormat" value="-1"/>
     </module>
     
     private int D2;
     // ALLOW MemberName ON PREVIOUS LINE
     . . .
     

    To configure a filter to allow suppress one or more Checks (separated by "|") and demand comment no less than 14 symbols:

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat"
         value="@cs\.suppress \[(\w+(\|\w+)*)\] \w[-\.'`,:;\w ]{14,}"/>
       <property name="checkFormat" value="$1"/>
       <property name="influenceFormat" value="1"/>
     </module>
     
     public static final int [] array; // @cs.suppress [ConstantName|NoWhitespaceAfter] A comment here
     

    It is possible to specify an ID of checks, so that it can be leveraged by the SuppressWithNearbyCommentFilter to skip validations. The following examples show how to skip validations near code that has comment like // @cs-: &lt;ID/&gt; (reason), where ID is the ID of checks you want to suppress.

    Examples of Checkstyle checks configuration:

     <module name="RegexpSinglelineJava">
       <property name="id" value="ignore"/>
       <property name="format" value="^.*@Ignore\s*$"/>
       <property name="message" value="@Ignore should have a reason."/>
     </module>
    
     <module name="RegexpSinglelineJava">
       <property name="id" value="systemout"/>
       <property name="format" value="^.*System\.(out|err).*$"/>
       <property name="message" value="Don't use System.out/err, use SLF4J instead."/>
     </module>
     

    Example of SuppressWithNearbyCommentFilter configuration (idFormat which is set to '$1' points that ID of the checks is in the first group of commentFormat regular expressions):

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat" value="@cs-: (\w+) \(.*\)"/>
       <property name="idFormat" value="$1"/>
       <property name="influenceFormat" value="0"/>
     </module>
     
     @Ignore // @cs-: ignore (test has not been implemented yet)
     @Test
     public void testMethod() { }
    
     public static void foo() {
       System.out.println("Debug info."); // @cs-: systemout (should not fail RegexpSinglelineJava)
     }
     

    Example of how to configure the check to suppress more than one checks. The influence format format is specified in the second regexp group.

     <module name="SuppressWithNearbyCommentFilter">
       <property name="commentFormat" value="@cs-\: ([\w\|]+) influence (\d+)"/>
       <property name="checkFormat" value="$1"/>
       <property name="influenceFormat" value="$2"/>
     </module>
     
     // @cs-: ClassDataAbstractionCoupling influence 2
     // @cs-: MagicNumber influence 4
     @Service // no violations from ClassDataAbstractionCoupling here
     @Transactional
     public class UserService {
       private int value = 10022; // no violations from MagicNumber here
     }
     

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Since:
    5.0
    • Method Detail

      • setCommentFormat

        public final void setCommentFormat​(Pattern pattern)
        Setter to specify comment pattern to trigger filter to begin suppression.
        Parameters:
        pattern - a pattern.
      • getFileContents

        private FileContents getFileContents()
        Returns FileContents for this filter.
        Returns:
        the FileContents for this filter.
      • setFileContents

        public void setFileContents​(FileContents fileContents)
        Set the FileContents for this filter.
        Parameters:
        fileContents - the FileContents for this filter.
      • setCheckFormat

        public final void setCheckFormat​(String format)
        Setter to specify check pattern to suppress.
        Parameters:
        format - a String value
      • setMessageFormat

        public void setMessageFormat​(String format)
        Setter to define message pattern to suppress.
        Parameters:
        format - a String value
      • setIdFormat

        public void setIdFormat​(String format)
        Setter to specify check ID pattern to suppress.
        Parameters:
        format - a String value
      • setInfluenceFormat

        public final void setInfluenceFormat​(String format)
        Setter to specify negative/zero/positive value that defines the number of lines preceding/at/following the suppression comment.
        Parameters:
        format - a String value
      • setCheckCPP

        public void setCheckCPP​(boolean checkCpp)
        Setter to control whether to check C++ style comments (//).
        Parameters:
        checkCpp - true if C++ comments are checked.
      • setCheckC

        public void setCheckC​(boolean checkC)
        Setter to control whether to check C style comments (&#47;* ... *&#47;).
        Parameters:
        checkC - true if C comments are checked.
      • finishLocalSetup

        protected void finishLocalSetup()
        Description copied from class: AutomaticBean
        Provides a hook to finish the part of this component's setup that was not handled by the bean introspection.

        The default implementation does nothing.

        Specified by:
        finishLocalSetup in class AutomaticBean
      • accept

        public boolean accept​(TreeWalkerAuditEvent event)
        Description copied from interface: TreeWalkerFilter
        Determines whether or not a filtered TreeWalkerAuditEvent is accepted.
        Specified by:
        accept in interface TreeWalkerFilter
        Parameters:
        event - the TreeWalkerAuditEvent to filter.
        Returns:
        true if the event is accepted.
      • matchesTag

        private boolean matchesTag​(TreeWalkerAuditEvent event)
        Whether current event matches any tag from tags.
        Parameters:
        event - TreeWalkerAuditEvent to test match on tags.
        Returns:
        true if event matches any tag from tags, false otherwise.
      • tagSuppressions

        private void tagSuppressions()
        Collects all the suppression tags for all comments into a list and sorts the list.
      • tagSuppressions

        private void tagSuppressions​(Collection<TextBlock> comments)
        Appends the suppressions in a collection of comments to the full set of suppression tags.
        Parameters:
        comments - the set of comments.
      • tagCommentLine

        private void tagCommentLine​(String text,
                                    int line)
        Tags a string if it matches the format for turning checkstyle reporting on or the format for turning reporting off.
        Parameters:
        text - the string to tag.
        line - the line number of text.
      • addTag

        private void addTag​(String text,
                            int line)
        Adds a comment suppression Tag to the list of all tags.
        Parameters:
        text - the text of the tag.
        line - the line number of the tag.