Package com.puppycrawl.tools.checkstyle.checks.javadoc

Class JavadocStyleCheck

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

    Validates Javadoc comments to help ensure they are well formed.

    The following checks are performed:

    • Ensures the first sentence ends with proper punctuation (That is a period, question mark, or exclamation mark, by default). Javadoc automatically places the first sentence in the method summary table and index. Without proper punctuation the Javadoc may be malformed. All items eligible for the {@inheritDoc} tag are exempt from this requirement.
    • Check text for Javadoc statements that do not have any description. This includes both completely empty Javadoc, and Javadoc with only tags such as @param and @return.
    • Check text for incomplete HTML tags. Verifies that HTML tags have corresponding end tags and issues an "Unclosed HTML tag found:" error if not. An "Extra HTML tag found:" error is issued if an end tag is found without a previous open tag.
    • Check that a package Javadoc comment is well-formed (as described above) and NOT missing from any package-info.java files.
    • Check for allowed HTML tags. The list of allowed HTML tags is "a", "abbr", "acronym", "address", "area", "b", "bdo", "big", "blockquote", "br", "caption", "cite", "code", "colgroup", "dd", "del", "dfn", "div", "dl", "dt", "em", "fieldset", "font", "h1", "h2", "h3", "h4", "h5", "h6", "hr", "i", "img", "ins", "kbd", "li", "ol", "p", "pre", "q", "samp", "small", "span", "strong", "sub", "sup", "table", "tbody", "td", "tfoot", "th", "thead", "tr", "tt", "u", "ul", "var".

    These checks were patterned after the checks made by the DocCheck doclet available from Sun. Note: Original Sun's DocCheck tool does not exist anymore.

    • Property scope - Specify the visibility scope where Javadoc comments are checked. Type is com.puppycrawl.tools.checkstyle.api.Scope. Default value is private.
    • Property excludeScope - Specify the visibility scope where Javadoc comments are not checked. Type is com.puppycrawl.tools.checkstyle.api.Scope. Default value is null.
    • Property checkFirstSentence - Control whether to check the first sentence for proper end of sentence. Type is boolean. Default value is true.
    • Property endOfSentenceFormat - Specify the format for matching the end of a sentence. Type is java.util.regex.Pattern. Default value is "([.?!][ \t\n\r\f<])|([.?!]$)".
    • Property checkEmptyJavadoc - Control whether to check if the Javadoc is missing a describing text. Type is boolean. Default value is false.
    • Property checkHtml - Control whether to check for incomplete HTML tags. Type is boolean. Default value is true.
    • Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: ANNOTATION_DEF, ANNOTATION_FIELD_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF, INTERFACE_DEF, METHOD_DEF, PACKAGE_DEF, VARIABLE_DEF, RECORD_DEF, COMPACT_CTOR_DEF.

    To configure the default check: 

     <module name="JavadocStyle"/>

    Example:

     public class Test {
     /**
      * Some description here. // OK
      */
     private void methodWithValidCommentStyle() {}

     /**
      * Some description here // violation, the sentence must end with a proper punctuation
      */
     private void methodWithInvalidCommentStyle() {}
 }

    To configure the check for public scope: 

     <module name="JavadocStyle">
   <property name="scope" value="public"/>
 </module>

    Example:

     public class Test {
     /**
      * Some description here // violation, the sentence must end with a proper punctuation
      */
     public void test1() {}

     /**
      * Some description here // OK
      */
     private void test2() {}
 }

    To configure the check for javadoc which is in private, but not in package scope: 

     <module name="JavadocStyle">
   <property name="scope" value="private"/>
   <property name="excludeScope" value="package"/>
 </module>

    Example:

     public class Test {
     /**
      * Some description here // violation, the sentence must end with a proper punctuation
      */
     private void test1() {}

     /**
      * Some description here // OK
      */
     void test2() {}
 }

    To configure the check to turn off first sentence checking: 

     <module name="JavadocStyle">
   <property name="checkFirstSentence" value="false"/>
 </module>

    Example:

     public class Test {
     /**
      * Some description here // OK
      * Second line of description // violation, the sentence must end with a proper punctuation
      */
     private void test1() {}
 }

    To configure the check to turn off validation of incomplete html tags: 

     <module name="JavadocStyle">
 <property name="checkHtml" value="false"/>
 </module>

    Example:

     public class Test {
     /**
      * Some description here // violation, the sentence must end with a proper punctuation
      * <p // OK
      */
     private void test1() {}
 }

    To configure the check for only class definitions: 

     <module name="JavadocStyle">
 <property name="tokens" value="CLASS_DEF"/>
 </module>

    Example:

     /**
  * Some description here // violation, the sentence must end with a proper punctuation
  */
 public class Test {
     /**
      * Some description here // OK
      */
     private void test1() {}
 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • javadoc.empty
    • javadoc.extraHtml
    • javadoc.incompleteTag
    • javadoc.missing
    • javadoc.noPeriod
    • javadoc.unclosedHtml
    Since:
    3.2

    • Field Detail

      • MSG_NO_PERIOD

        public static final java.lang.String MSG_NO_PERIOD
        Message property key for the No Javadoc end of Sentence Period message.
        See Also:
        Constant Field Values

      • SINGLE_TAGS

        private static final java.util.Set<java.lang.String> SINGLE_TAGS
        HTML tags that do not require a close tag.

      • ALLOWED_TAGS

        private static final java.util.Set<java.lang.String> ALLOWED_TAGS
        HTML tags that are allowed in java docs. From https://www.w3schools.com/tags/default.asp The forms and structure tags are not allowed

      • scope

        private Scope scope
        Specify the visibility scope where Javadoc comments are checked.

      • excludeScope

        private Scope excludeScope
        Specify the visibility scope where Javadoc comments are not checked.

      • endOfSentenceFormat

        private java.util.regex.Pattern endOfSentenceFormat
        Specify the format for matching the end of a sentence.

      • checkFirstSentence

        private boolean checkFirstSentence
        Control whether to check the first sentence for proper end of sentence.

      • checkHtml

        private boolean checkHtml
        Control whether to check for incomplete HTML tags.

      • checkEmptyJavadoc

        private boolean checkEmptyJavadoc
        Control whether to check if the Javadoc is missing a describing text.

    • Method Detail

      • 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

      • shouldCheck

        private boolean shouldCheck​(DetailAST ast)
        Whether we should check this node.
        Parameters:
        ast - a given node.
        Returns:
        whether we should check a given node.

      • checkFirstSentenceEnding

        private void checkFirstSentenceEnding​(DetailAST ast,
                                      TextBlock comment)
        Checks that the first sentence ends with proper punctuation. This method uses a regular expression that checks for the presence of a period, question mark, or exclamation mark followed either by whitespace, an HTML element, or the end of string. This method ignores {_AT_inheritDoc} comments for TokenTypes that are valid for {_AT_inheritDoc}.
        Parameters:
        ast - the current node
        comment - the source lines that make up the Javadoc comment.

      • checkJavadocIsNotEmpty

        private void checkJavadocIsNotEmpty​(TextBlock comment)
        Checks that the Javadoc is not empty.
        Parameters:
        comment - the source lines that make up the Javadoc comment.

      • getCommentText

        private static java.lang.String getCommentText​(java.lang.String... comments)
        Returns the comment text from the Javadoc.
        Parameters:
        comments - the lines of Javadoc.
        Returns:
        a comment text String.

      • findTextStart

        private static int findTextStart​(java.lang.String line)
        Finds the index of the first non-whitespace character ignoring the Javadoc comment start and end strings (/** and */) as well as any leading asterisk.
        Parameters:
        line - the Javadoc comment line of text to scan.
        Returns:
        the int index relative to 0 for the start of text or -1 if not found.

      • trimTail

        private static void trimTail​(java.lang.StringBuilder builder)
        Trims any trailing whitespace or the end of Javadoc comment string.
        Parameters:
        builder - the StringBuilder to trim.

      • checkHtmlTags

        private void checkHtmlTags​(DetailAST ast,
                           TextBlock comment)
        Checks the comment for HTML tags that do not have a corresponding close tag or a close tag that has no previous open tag. This code was primarily copied from the DocCheck checkHtml method.
        Parameters:
        ast - the node with the Javadoc
        comment - the TextBlock which represents the Javadoc comment.

      • checkUnclosedTags

        private void checkUnclosedTags​(java.util.Deque<HtmlTag> htmlStack,
                               java.lang.String token)
        Checks to see if there are any unclosed tags on the stack. The token represents a html tag that has been closed and has a corresponding open tag on the stack. Any tags, except single tags, that were opened (pushed on the stack) after the token are missing a close.
        Parameters:
        htmlStack - the stack of opened HTML tags.
        token - the current HTML tag name that has been closed.

      • isSingleTag

        private static boolean isSingleTag​(HtmlTag tag)
        Determines if the HtmlTag is one which does not require a close tag.
        Parameters:
        tag - the HtmlTag to check.
        Returns:
        true if the HtmlTag is a single tag.

      • isAllowedTag

        private static boolean isAllowedTag​(HtmlTag tag)
        Determines if the HtmlTag is one which is allowed in a javadoc.
        Parameters:
        tag - the HtmlTag to check.
        Returns:
        true if the HtmlTag is an allowed html tag.

      • isExtraHtml

        private static boolean isExtraHtml​(java.lang.String token,
                                   java.util.Deque<HtmlTag> htmlStack)
        Determines if the given token is an extra HTML tag. This indicates that a close tag was found that does not have a corresponding open tag.
        Parameters:
        token - an HTML tag id for which a close was found.
        htmlStack - a Stack of previous open HTML tags.
        Returns:
        false if a previous open tag was found for the token.

      • setScope

        public void setScope​(Scope scope)
        Setter to specify the visibility scope where Javadoc comments are checked.
        Parameters:
        scope - a scope.

      • setExcludeScope

        public void setExcludeScope​(Scope excludeScope)
        Setter to specify the visibility scope where Javadoc comments are not checked.
        Parameters:
        excludeScope - a scope.

      • setEndOfSentenceFormat

        public void setEndOfSentenceFormat​(java.util.regex.Pattern pattern)
        Setter to specify the format for matching the end of a sentence.
        Parameters:
        pattern - a pattern.

      • setCheckFirstSentence

        public void setCheckFirstSentence​(boolean flag)
        Setter to control whether to check the first sentence for proper end of sentence.
        Parameters:
        flag - true if the first sentence is to be checked

      • setCheckHtml

        public void setCheckHtml​(boolean flag)
        Setter to control whether to check for incomplete HTML tags.
        Parameters:
        flag - true if HTML checking is to be performed.

      • setCheckEmptyJavadoc

        public void setCheckEmptyJavadoc​(boolean flag)
        Setter to control whether to check if the Javadoc is missing a describing text.
        Parameters:
        flag - true if empty Javadoc checking should be done.