com.puppycrawl.tools.checkstyle.checks.whitespace

Class WhitespaceAroundCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAroundCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class WhitespaceAroundCheck
extends AbstractCheck

Checks that a token is surrounded by whitespace. Empty constructor, method, class, enum, interface, loop bodies (blocks), lambdas of the form

 public MyClass() {}      // empty constructor
 public void func() {}    // empty method
 public interface Foo {} // empty interface
 public class Foo {} // empty class
 public enum Foo {} // empty enum
 MyClass c = new MyClass() {}; // empty anonymous class
 while (i = 1) {} // empty while loop
 for (int i = 1; i > 1; i++) {} // empty for loop
 do {} while (i = 1); // empty do-while loop
 Runnable noop = () -> {}; // empty lambda
 public @interface Beta {} // empty annotation type
 

may optionally be exempted from the policy using the allowEmptyMethods, allowEmptyConstructors, allowEmptyTypes, allowEmptyLoops, allowEmptyLambdas and allowEmptyCatches properties.

This check does not flag as violation double brace initialization like:

 new Properties() {{
     setProperty("key", "value");
 }};
 

Parameter allowEmptyCatches allows to suppress violations when token list contains SLIST to check if beginning of block is surrounded by whitespace and catch block is empty, for example:

 try {
     k = 5 / i;
 } catch (ArithmeticException ex) {}
 

With this property turned off, this raises violation because the beginning of the catch block (left curly bracket) is not separated from the end of the catch block (right curly bracket).

• Property allowEmptyConstructors - Allow empty constructor bodies. Default value is false.
• Property allowEmptyMethods - Allow empty method bodies. Default value is false.
• Property allowEmptyTypes - Allow empty class, interface and enum bodies. Default value is false.
• Property allowEmptyLoops - Allow empty loop bodies. Default value is false.
• Property allowEmptyLambdas - Allow empty lambda bodies. Default value is false.
• Property allowEmptyCatches - Allow empty catch bodies. Default value is false.
• Property ignoreEnhancedForColon - Ignore whitespace around colon in enhanced for loop. Default value is true.
• Property tokens - tokens to check Default value is: ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND, LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, 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, LITERAL_ASSERT, TYPE_EXTENSION_AND.

To configure the check:

 <module name="WhitespaceAround"/>
 

To configure the check for whitespace only around assignment operators:

 <module name="WhitespaceAround">
   <property name="tokens"
     value="ASSIGN,DIV_ASSIGN,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,
            MOD_ASSIGN,SR_ASSIGN,BSR_ASSIGN,SL_ASSIGN,BXOR_ASSIGN,
            BOR_ASSIGN,BAND_ASSIGN"/>
 </module>
 

To configure the check for whitespace only around curly braces:

 <module name="WhitespaceAround">
   <property name="tokens" value="LCURLY,RCURLY"/>
 </module>
 

To configure the check to allow empty method bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyMethods" value="true"/>
 </module>
 

To configure the check to allow empty constructor bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyConstructors" value="true"/>
 </module>
 

To configure the check to allow empty type bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyTypes" value="true"/>
 </module>
 

To configure the check to allow empty loop bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyLoops" value="true"/>
 </module>
 

To configure the check to allow empty lambda bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyLambdas" value="true"/>
 </module>
 

To configure the check to allow empty catch bodies:

 <module name="WhitespaceAround">
   <property name="allowEmptyCatches" value="true"/>
 </module>
 

Also, this check can be configured to ignore the colon in an enhanced for loop. The colon in an enhanced for loop is ignored by default.

To configure the check to ignore the colon:

 <module name="WhitespaceAround">
   <property name="ignoreEnhancedForColon" value="true" />
 </module>
 

Since:

3.0

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

AutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	MSG_WS_NOT_FOLLOWED A key is pointing to the warning message text in "messages.properties" file.
static java.lang.String	MSG_WS_NOT_PRECEDED A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
WhitespaceAroundCheck()

Method Summary

Modifier and Type	Method and Description
int[]	getAcceptableTokens() The configurable token set.
int[]	getDefaultTokens() Returns the default token a check is interested in.
int[]	getRequiredTokens() The tokens that this check must be registered for.
void	setAllowEmptyCatches(boolean allow) Setter to allow empty catch bodies.
void	setAllowEmptyConstructors(boolean allow) Setter to allow empty constructor bodies.
void	setAllowEmptyLambdas(boolean allow) Setter to allow empty lambda bodies.
void	setAllowEmptyLoops(boolean allow) Setter to allow empty loop bodies.
void	setAllowEmptyMethods(boolean allow) Setter to allow empty method bodies.
void	setAllowEmptyTypes(boolean allow) Setter to allow empty class, interface and enum bodies.
void	setIgnoreEnhancedForColon(boolean ignore) Setter to ignore whitespace around colon in enhanced for loop.
void	visitToken(DetailAST ast) Called to process a token.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MSG_WS_NOT_PRECEDED

public static final java.lang.String MSG_WS_NOT_PRECEDED

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

MSG_WS_NOT_FOLLOWED

public static final java.lang.String MSG_WS_NOT_FOLLOWED

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

Constructor Detail

WhitespaceAroundCheck

public WhitespaceAroundCheck()

Method Detail

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:

TokenTypes

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

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:

TokenTypes

setAllowEmptyMethods

public void setAllowEmptyMethods(boolean allow)

Setter to allow empty method bodies.

Parameters:

allow - true to allow empty method bodies.

setAllowEmptyConstructors

public void setAllowEmptyConstructors(boolean allow)

Setter to allow empty constructor bodies.

Parameters:

allow - true to allow empty constructor bodies.

setIgnoreEnhancedForColon

public void setIgnoreEnhancedForColon(boolean ignore)

Setter to ignore whitespace around colon in enhanced for loop.

Parameters:

ignore - true to ignore enhanced for colon.

setAllowEmptyTypes

public void setAllowEmptyTypes(boolean allow)

Setter to allow empty class, interface and enum bodies.

Parameters:

allow - true to allow empty type bodies.

setAllowEmptyLoops

public void setAllowEmptyLoops(boolean allow)

Setter to allow empty loop bodies.

Parameters:

allow - true to allow empty loops bodies.

setAllowEmptyLambdas

public void setAllowEmptyLambdas(boolean allow)

Setter to allow empty lambda bodies.

Parameters:

allow - true to allow empty lambda expressions.

setAllowEmptyCatches

public void setAllowEmptyCatches(boolean allow)

Setter to allow empty catch bodies.

Parameters:

allow - true to allow empty catch blocks.

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