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

Class GenericWhitespaceCheck

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.GenericWhitespaceCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class GenericWhitespaceCheck extends AbstractCheck
Checks that the whitespace around the Generic tokens (angle brackets) "<" and ">" are correct to the typical convention. The convention is not configurable.

Left angle bracket ("<"):

  • should be preceded with whitespace only in generic methods definitions.
  • should not be preceded with whitespace when it is preceded method name or constructor.
  • should not be preceded with whitespace when following type name.
  • should not be followed with whitespace in all cases.

Right angle bracket (">"):

  • should not be preceded with whitespace in all cases.
  • should be followed with whitespace in almost all cases, except diamond operators and when preceding a method name, constructor, or record header.

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • ws.followed
  • ws.illegalFollow
  • ws.notPreceded
  • ws.preceded
Since:
5.0

  • Field Details

  • Constructor Details

  • Method Details

    • 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:

    • 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

    • 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

    • processEnd

      private void processEnd(DetailAST ast)
      Checks the token for the end of Generics.
      Parameters:
      ast - the token to check

    • processNestedGenerics

      private void processNestedGenerics(DetailAST ast, int[] line, int after)
      Process Nested generics.
      Parameters:
      ast - token
      line - unicode code points array of line
      after - position after

    • processSingleGeneric

      private void processSingleGeneric(DetailAST ast, int[] line, int after)
      Process Single-generic.
      Parameters:
      ast - token
      line - unicode code points array of line
      after - position after

    • isGenericBeforeRecordHeader

      private static boolean isGenericBeforeRecordHeader(DetailAST ast)
      Checks if generic is before record header. Identifies two cases:
      1. In record def, eg: record Session<T>()
      2. In record pattern def, eg: o instanceof Session<String>(var s)
      Parameters:
      ast - ast
      Returns:
      true if generic is before record header

    • isGenericBeforeCtorInvocation

      private static boolean isGenericBeforeCtorInvocation(DetailAST ast)
      Checks if generic is before constructor invocation. Identifies two cases:
      1. new ArrayList<>();
      2. new Outer.Inner<>();
      Parameters:
      ast - ast
      Returns:
      true if generic is before constructor invocation

    • isGenericAfterNew

      private static boolean isGenericAfterNew(DetailAST ast)
      Checks if generic is after LITERAL_NEW. Identifies three cases:
      1. new <String>Object();
      2. new <String>Outer.Inner();
      3. new <@A Outer>@B Inner();
      Parameters:
      ast - ast
      Returns:
      true if generic after LITERAL_NEW

    • isGenericBeforeMethod

      private static boolean isGenericBeforeMethod(DetailAST ast)
      Is generic before method reference.
      Parameters:
      ast - ast
      Returns:
      true if generic before a method ref

    • isAfterMethodReference

      private static boolean isAfterMethodReference(DetailAST genericEnd)
      Checks if current generic end ('>') is located after method reference operator.
      Parameters:
      genericEnd - TokenTypes.GENERIC_END
      Returns:
      true if '>' follows after method reference.

    • processStart

      private void processStart(DetailAST ast)
      Checks the token for the start of Generics.
      Parameters:
      ast - the token to check

    • containsWhitespaceBetween

      private static boolean containsWhitespaceBetween(int fromIndex, int toIndex, int... line)
      Returns whether the specified string contains only whitespace between specified indices.
      Parameters:
      fromIndex - the index to start the search from. Inclusive
      toIndex - the index to finish the search. Exclusive
      line - the unicode code points array of line to check
      Returns:
      whether there are only whitespaces (or nothing)

    • containsWhitespaceBefore

      private static boolean containsWhitespaceBefore(int before, int... line)
      Returns whether the specified string contains only whitespace up to specified index.
      Parameters:
      before - the index to finish the search. Exclusive
      line - the unicode code points array of line to check
      Returns:
      true if there are only whitespaces, false if there is nothing before or some other characters

    • isCharacterValidAfterGenericEnd

      private static boolean isCharacterValidAfterGenericEnd(char charAfter)
      Checks whether given character is valid to be right after generic ends.
      Parameters:
      charAfter - character to check
      Returns:
      checks if given character is valid