Checks for whitespace

NoWhitespaceAfter

Description

Checks that there is no whitespace after a token. More specifically, it checks that it is not followed by whitespace, or (if linebreaks are allowed) all characters on the line after are whitespace. To forbid linebreaks after a token, set property allowLineBreaks to false.

Properties

name	description	type	default value
allowLineBreaks	whether whitespace is allowed if the token is at a linebreak	boolean	true
tokens	tokens to check	subset of tokens ARRAY_INIT, BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS	ARRAY_INIT, BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS

Examples

To configure the check:

<module name="NoWhitespaceAfter"/>

To configure the check to forbid linebreaks after a DOT token:

<module name="NoWhitespaceAfter">
    <property name="tokens" value="DOT"/>
    <property name="allowLineBreaks" value="false"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

NoWhitespaceBefore

Description

Checks that there is no whitespace before a token. More specifically, it checks that it is not preceded with whitespace, or (if linebreaks are allowed) all characters on the line before are whitespace. To allow linebreaks before a token, set property allowLineBreaks to true.

Properties

name	description	type	default value
allowLineBreaks	whether whitespace is allowed if the token is at a linebreak	boolean	false
tokens	tokens to check	subset of tokens SEMI, DOT, POST_DEC, POST_INC	SEMI, POST_DEC, POST_INC

Examples

To configure the check:

<module name="NoWhitespaceBefore"/>

To configure the check to allow linebreaks before a DOT token:

<module name="NoWhitespaceBefore">
    <property name="tokens" value="DOT"/>
    <property name="allowLineBreaks" value="true"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

OperatorWrap

Description

Checks the policy on how to wrap lines on operators.

Properties

name	description	type	default value
option	policy on how to wrap lines	wrap operator policy	nl
tokens	tokens to check	subset of tokens ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, SL, SL_ASSIGN, SR, SR_ASSIGN, STAR, STAR_ASSIGN	BAND, BOR, BSR, BXOR, COLON, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR (all tokens except assignment operators)

Examples

To configure the check:

<module name="OperatorWrap"/>

To configure the check for the assignment operator, =, at the end of a line:

<module name="OperatorWrap">
    <property name="tokens" value="ASSIGN"/>
    <property name="option" value="eol"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

ParenPad

Description

Checks the policy on the padding of parentheses; i.e. whether a space is required after a left parenthesis and before a right parenthesis, or such spaces are forbidden.

Properties

name	description	type	default value
option	policy on how to pad parentheses	pad parentheses policy	nospace
tokens	tokens to check	subset of tokens CTOR_CALL, LPAREN, METHOD_CALL, RPAREN, SUPER_CTOR_CALL, TYPECAST	CTOR_CALL, LPAREN, METHOD_CALL, RPAREN, SUPER_CTOR_CALL, TYPECAST

Examples

To configure the check:

<module name="ParenPad"/>

To configure the check to require spaces for the parentheses of constructor, method, and super constructor calls:

<module name="ParenPad">
    <property name="tokens" value="CTOR_CALL, METHOD_CALL,
    SUPER_CTOR_CALL"/>
    <property name="option" value="space"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

TabCharacter

Description

Checks that there are no tab characters ('\t') in the source code.

Rationale:

Developers should not need to configure the tab width of their text editors in order to be able to read source code.
From the Apache jakarta coding standards: In a distributed development environment, when the cvs commit messages get sent to a mailing list, they are almost impossible to read if you use tabs.

Example

To configure the check:

<module name="TabCharacter"/>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

WhitespaceAfter

Description

Checks that a token is followed by whitespace.

Properties

name	description	type	default value
tokens	tokens to check	subset of tokens COMMA, SEMI, TYPECAST	COMMA, SEMI, TYPECAST

Examples

To configure the check:

<module name="WhitespaceAfter"/>

To configure the check for whitespace only after COMMA and SEMI tokens:

<module name="WhitespaceAfter">
    <property name="tokens" value="COMMA, SEMI"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker

WhitespaceAround

Description

Checks that a token is surrounded by whitespace.

Properties

name	description	type	default value
tokens	tokens to check	subset of tokens ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, EQUAL, GE, GT, LAND, LCURLY, LE, LITERAL_ASSERT, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR, SR_ASSIGN, STAR, STAR_ASSIGN STAR_ASSIGN	all tokens

Examples

To configure the check:

<module name="WhitespaceAround"/>

To configure the check for whitespace around the assignment operator, =:

<module name="WhitespaceAround">
    <property name="tokens" value="ASSIGN"/>
</module>

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker