Package com.puppycrawl.tools.checkstyle.checks.whitespace

Class EmptyLineSeparatorCheck

java.lang.Object
com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
com.puppycrawl.tools.checkstyle.api.AbstractCheck
com.puppycrawl.tools.checkstyle.checks.whitespace.EmptyLineSeparatorCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class EmptyLineSeparatorCheck extends AbstractCheck
Checks for empty line separators before package, all import declarations, fields, constructors, methods, nested classes, static initializers and instance initializers.

Checks for empty line separators before not only statements but implementation and documentation comments and blocks as well.

ATTENTION: empty line separator is required between token siblings, not after line where token is found. If token does not have a sibling of the same type, then empty line is required at its end (for example for CLASS_DEF it is after '}'). Also, trailing comments are skipped.

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • empty.line.separator
  • empty.line.separator.multiple.lines
  • empty.line.separator.multiple.lines.after
  • empty.line.separator.multiple.lines.inside
Since:
5.8

  • Field Details

  • Constructor Details

  • Method Details

    • setAllowNoEmptyLineBetweenFields

      public final void setAllowNoEmptyLineBetweenFields(boolean allow)
      Setter to allow no empty line between fields.
      Parameters:
      allow - User's value.
      Since:
      5.8

    • setAllowMultipleEmptyLines

      public void setAllowMultipleEmptyLines(boolean allow)
      Setter to allow multiple empty lines between class members.
      Parameters:
      allow - User's value.
      Since:
      6.3

    • setAllowMultipleEmptyLinesInsideClassMembers

      public void setAllowMultipleEmptyLinesInsideClassMembers(boolean allow)
      Setter to allow multiple empty lines inside class members.
      Parameters:
      allow - User's value.
      Since:
      6.18

    • isCommentNodesRequired

      public boolean isCommentNodesRequired()
      Description copied from class: AbstractCheck
      Whether comment nodes are required or not.
      Overrides:
      isCommentNodesRequired in class AbstractCheck
      Returns:
      false as a default value.

    • 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:

    • 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:

    • 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:

    • visitToken

      public void visitToken(DetailAST ast)
      Description copied from class: AbstractCheck
      Called to process a token.
      Overrides:
      visitToken in class AbstractCheck
      Parameters:
      ast - the token to process

    • checkToken

      private void checkToken(DetailAST ast, DetailAST nextToken)
      Checks that token and next token are separated.
      Parameters:
      ast - token to validate
      nextToken - next sibling of the token

    • checkCommentInModifiers

      private void checkCommentInModifiers(DetailAST packageDef)
      Checks that packageDef token is separated from comment in modifiers.
      Parameters:
      packageDef - package def token

    • processMultipleLinesInside

      private void processMultipleLinesInside(DetailAST ast)
      Log violation in case there are multiple empty lines inside constructor, initialization block or method.
      Parameters:
      ast - the ast to check.

    • getLastElementBeforeEmptyLines

      private static DetailAST getLastElementBeforeEmptyLines(DetailAST ast, int line)
      Returns the element after which empty lines exist.
      Parameters:
      ast - the ast to check.
      line - the empty line which gives violation.
      Returns:
      The DetailAST after which empty lines are present.

    • getPostFixNode

      private static Optional<DetailAST> getPostFixNode(DetailAST ast)
      Gets postfix Node from AST if present.
      Parameters:
      ast - the AST used to get postfix Node.
      Returns:
      Optional postfix node.

    • isClassMemberBlock

      private static boolean isClassMemberBlock(int astType)
      Whether the AST is a class member block.
      Parameters:
      astType - the AST to check.
      Returns:
      true if the AST is a class member block.

    • getEmptyLines

      private List<Integer> getEmptyLines(DetailAST ast)
      Get list of empty lines.
      Parameters:
      ast - the ast to check.
      Returns:
      list of line numbers for empty lines.

    • getEmptyLinesToLog

      private static List<Integer> getEmptyLinesToLog(Iterable<Integer> emptyLines)
      Get list of empty lines to log.
      Parameters:
      emptyLines - list of empty lines.
      Returns:
      list of empty lines to log.

    • hasMultipleLinesBefore

      private boolean hasMultipleLinesBefore(DetailAST ast)
      Whether the token has not allowed multiple empty lines before.
      Parameters:
      ast - the ast to check.
      Returns:
      true if the token has not allowed multiple empty lines before.

    • processPackage

      private void processPackage(DetailAST ast, DetailAST nextToken)
      Process Package.
      Parameters:
      ast - token
      nextToken - next token

    • isLineEmptyAfterPackage

      private static boolean isLineEmptyAfterPackage(DetailAST ast)
      Checks if there is another element at next line of package declaration.
      Parameters:
      ast - Package ast.
      Returns:
      true, if there is an element.

    • getViolationAstForPackage

      private static DetailAST getViolationAstForPackage(DetailAST ast)
      Gets the Ast on which violation is to be given for package declaration.
      Parameters:
      ast - Package ast.
      Returns:
      Violation ast.

    • processImport

      private void processImport(DetailAST ast, DetailAST nextToken)
      Process Import.
      Parameters:
      ast - token
      nextToken - next token

    • processVariableDef

      private void processVariableDef(DetailAST ast, DetailAST nextToken)
      Process Variable.
      Parameters:
      ast - token
      nextToken - next Token

    • isViolatingEmptyLineBetweenFieldsPolicy

      private boolean isViolatingEmptyLineBetweenFieldsPolicy(DetailAST detailAST)
      Checks whether token placement violates policy of empty line between fields.
      Parameters:
      detailAST - token to be analyzed
      Returns:
      true if policy is violated and warning should be raised; false otherwise

    • hasNotAllowedTwoEmptyLinesBefore

      private boolean hasNotAllowedTwoEmptyLinesBefore(DetailAST token)
      Checks if a token has empty two previous lines and multiple empty lines is not allowed.
      Parameters:
      token - DetailAST token
      Returns:
      true, if token has empty two lines before and allowMultipleEmptyLines is false

    • checkComments

      private void checkComments(DetailAST token)
      Check if group of comments located right before token has more than one previous empty line.
      Parameters:
      token - DetailAST token

    • checkCommentsInsideToken

      private void checkCommentsInsideToken(DetailAST token)
      Check if group of comments located at the start of token has more than one previous empty line.
      Parameters:
      token - DetailAST token

    • isPrePreviousLineEmpty

      private boolean isPrePreviousLineEmpty(DetailAST token)
      Checks if a token has empty pre-previous line.
      Parameters:
      token - DetailAST token.
      Returns:
      true, if token has empty lines before.

    • hasEmptyLineAfter

      private boolean hasEmptyLineAfter(DetailAST token)
      Checks if token have empty line after.
      Parameters:
      token - token.
      Returns:
      true if token have empty line after.

    • findCommentUnder

      private static Optional<DetailAST> findCommentUnder(DetailAST packageDef)
      Finds comment in next sibling of given packageDef.
      Parameters:
      packageDef - token to check
      Returns:
      comment under the token

    • hasEmptyLine

      private boolean hasEmptyLine(int startLine, int endLine)
      Checks, whether there are empty lines within the specified line range. Line numbering is started from 1 for parameter values
      Parameters:
      startLine - number of the first line in the range
      endLine - number of the second line in the range
      Returns:
      true if found any blank line within the range, false otherwise

    • hasEmptyLineBefore

      private boolean hasEmptyLineBefore(DetailAST token)
      Checks if a token has an empty line before.
      Parameters:
      token - token.
      Returns:
      true, if token have empty line before.

    • isCommentInBeginningOfLine

      private boolean isCommentInBeginningOfLine(DetailAST comment)
      Check if token is comment, which starting in beginning of line.
      Parameters:
      comment - comment token for check.
      Returns:
      true, if token is comment, which starting in beginning of line.

    • isPrecededByJavadoc

      private static boolean isPrecededByJavadoc(DetailAST token)
      Check if token is preceded by javadoc comment.
      Parameters:
      token - token for check.
      Returns:
      true, if token is preceded by javadoc comment.

    • isTypeField

      private static boolean isTypeField(DetailAST variableDef)
      If variable definition is a type field.
      Parameters:
      variableDef - variable definition.
      Returns:
      true variable definition is a type field.