Class SingleSpaceSeparatorCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks that non-whitespace characters are separated by no more than one
whitespace. Separating characters by tabs or multiple spaces will be
reported. Currently the check doesn't permit horizontal alignment. To inspect
whitespaces before and after comments, set the property
validateComments
to true.
Setting validateComments
to false will ignore cases like:
int i; // Multiple whitespaces before comment tokens will be ignored. private void foo(int /* whitespaces before and after block-comments will be ignored */ i) {
Sometimes, users like to space similar items on different lines to the same column position for easier reading. This feature isn't supported by this check, so both braces in the following case will be reported as violations.
public long toNanos(long d) { return d; } // 2 violations public long toMicros(long d) { return d / (C1 / C0); }
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Property
validateComments
- Control whether to validate whitespaces surrounding comments. Type isboolean
. Default value isfalse
.
To configure the check:
<module name="SingleSpaceSeparator"/>
Example:
int foo() { // violation, 3 whitespaces return 1; // violation, 2 whitespaces } int fun1() { // OK, 1 whitespace return 3; // OK, 1 whitespace } void fun2() {} // violation, 2 whitespaces
To configure the check so that it validates comments:
<module name="SingleSpaceSeparator"> <property name="validateComments" value="true"/> </module>
Example:
void fun1() {} // violation, 2 whitespaces before the comment starts void fun2() { return; } /* violation here, 2 whitespaces before the comment starts */ /* violation, 2 whitespaces after the comment ends */ int a; String s; /* OK, 1 whitespace */ /** * This is a Javadoc comment */ int b; // violation, 2 whitespaces after the javadoc comment ends float f1; // OK, 1 whitespace /** * OK, 1 white space after the doc comment ends */ float f2;
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
single.space.separator
- Since:
- 6.19
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Nested Class Summary
Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
A key is pointing to the warning message text in "messages.properties" file.private boolean
Control whether to validate whitespaces surrounding comments. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Called before the starting to process a tree.int[]
The configurable token set.int[]
Returns the default token a check is interested in.int[]
The tokens that this check must be registered for.private static boolean
isBlockCommentEnd
(String line, int columnNo) Checks if theline
atcolumnNo
is the end of a comment, '*/'.boolean
Whether comment nodes are required or not.private static boolean
isFirstInLine
(String line, int columnNo) Checks if theline
up to and includingcolumnNo
is all non-whitespace text encountered.private static boolean
isSingleSpace
(String line, int columnNo) Checks if theline
atcolumnNo
is a single space, and not preceded by another space.private static boolean
Checks if theline
atcolumnNo
is a space.private boolean
isTextSeparatedCorrectlyFromPrevious
(String line, int columnNo) Checks if characters inline
at and aroundcolumnNo
has the correct number of spaces.private static boolean
isWhitespace
(String line, int columnNo) Checks if theline
atcolumnNo
is a whitespace character.void
setValidateComments
(boolean validateComments) Setter to control whether to validate whitespaces surrounding comments.private void
visitEachToken
(DetailAST node) Examines every sibling and child ofnode
for violations.Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
clearViolations, destroy, finishTree, getFileContents, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens, visitToken
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
configure, contextualize, getConfiguration, setupChild
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Field Details
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MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
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validateComments
private boolean validateCommentsControl whether to validate whitespaces surrounding comments.
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Constructor Details
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SingleSpaceSeparatorCheck
public SingleSpaceSeparatorCheck()
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Method Details
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setValidateComments
public void setValidateComments(boolean validateComments) Setter to control whether to validate whitespaces surrounding comments.- Parameters:
validateComments
-true
to validate surrounding whitespaces at comments.
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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 classAbstractCheck
- Returns:
- the default tokens
- See Also:
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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 classAbstractCheck
- Returns:
- the token set this check is designed for.
- See Also:
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getRequiredTokens
public int[] getRequiredTokens()Description copied from class:AbstractCheck
The tokens that this check must be registered for.- Specified by:
getRequiredTokens
in classAbstractCheck
- Returns:
- the token set this must be registered for.
- See Also:
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isCommentNodesRequired
public boolean isCommentNodesRequired()Description copied from class:AbstractCheck
Whether comment nodes are required or not.- Overrides:
isCommentNodesRequired
in classAbstractCheck
- Returns:
- false as a default value.
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beginTree
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 classAbstractCheck
- Parameters:
rootAST
- the root of the tree
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visitEachToken
Examines every sibling and child ofnode
for violations.- Parameters:
node
- The node to start examining.
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isTextSeparatedCorrectlyFromPrevious
Checks if characters inline
at and aroundcolumnNo
has the correct number of spaces. to returntrue
the following conditions must be met:- the character at
columnNo
is the first in the line. - the character at
columnNo
is not separated by whitespaces from the previous non-whitespace character. - the character at
columnNo
is separated by only one whitespace from the previous non-whitespace character. -
validateComments
is disabled and the previous text is the end of a block comment.
- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the text atcolumnNo
is separated correctly from the previous token.
- the character at
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isSingleSpace
Checks if theline
atcolumnNo
is a single space, and not preceded by another space.- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the character atcolumnNo
is a space, and not preceded by another space.
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isSpace
Checks if theline
atcolumnNo
is a space.- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the character atcolumnNo
is a space.
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isWhitespace
Checks if theline
atcolumnNo
is a whitespace character.- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the character atcolumnNo
is a whitespace.
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isFirstInLine
Checks if theline
up to and includingcolumnNo
is all non-whitespace text encountered.- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the column position is the first non-whitespace text on theline
.
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isBlockCommentEnd
Checks if theline
atcolumnNo
is the end of a comment, '*/'.- Parameters:
line
- The line in the file to examine.columnNo
- The column position in theline
to examine.- Returns:
true
if the previous text is a end comment block.
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