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).
allowEmptyConstructors - Allow empty constructor bodies.
Type is boolean.
Default value is false.
allowEmptyMethods - Allow empty method bodies.
Type is boolean.
Default value is false.
allowEmptyTypes - Allow empty class, interface and enum bodies.
Type is boolean.
Default value is false.
allowEmptyLoops - Allow empty loop bodies.
Type is boolean.
Default value is false.
allowEmptyLambdas - Allow empty lambda bodies.
Type is boolean.
Default value is false.
allowEmptyCatches - Allow empty catch bodies.
Type is boolean.
Default value is false.
ignoreEnhancedForColon - Ignore whitespace around colon in
enhanced for loop.
Type is boolean.
Default value is true.
tokens - tokens to check
Type is int[].
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"/>
Example:
class Test {
public Test(){} // 2 violations, '{' is not followed and preceded by whitespace.
public static void main(String[] args) {
if (foo) { // ok
// body
}
else{ // violation
// body
}
for (int i = 1; i > 1; i++) {} // violation, '{' is not followed by whitespace.
Runnable noop = () ->{}; // 2 violations,
// '{' is not followed and preceded by whitespace.
try {
// body
} catch (Exception e){} // 2 violations,
// '{' is not followed and preceded by whitespace.
char[] vowels = {'a', 'e', 'i', 'o', 'u'};
for (char item: vowels) { // ok, because ignoreEnhancedForColon is true by default
// body
}
}
}
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>
Example:
class Test {
public static void main(String[] args) {
int b=10; // violation
int c = 10; // ok
b+=10; // violation
b += 10; // ok
c*=10; // violation
c *= 10; // ok
c-=5; // violation
c -= 5; // ok
c/=2; // violation
c /= 2; // ok
c%=1; // violation
c %= 1; // ok
c>>=1; // violation
c >>= 1; // ok
c>>>=1; // violation
c >>>= 1; // ok
}
public void myFunction() {
c^=1; // violation
c ^= 1; // ok
c|=1; // violation
c |= 1; // ok
c&=1; // violation
c &= 1; // ok
c<<=1; // violation
c <<= 1; // ok
}
}
To configure the check for whitespace only around curly braces:
<module name="WhitespaceAround"> <property name="tokens" value="LCURLY,RCURLY"/> </module>
Example:
class Test {
public void myFunction() {} // violation
public void myFunction() { } // ok
}
To configure the check to allow empty method bodies:
<module name="WhitespaceAround"> <property name="allowEmptyMethods" value="true"/> </module>
Example:
class Test {
public void muFunction() {} // ok
int a=4; // 2 violations, '=' is not followed and preceded by whitespace.
}
To configure the check to allow empty constructor bodies:
<module name="WhitespaceAround"> <property name="allowEmptyConstructors" value="true"/> </module>
Example:
class Test {
public Test(){} // ok
public void muFunction() {} // violation, '{' is not followed by whitespace.
}
To configure the check to allow empty type bodies:
<module name="WhitespaceAround"> <property name="allowEmptyTypes" value="true"/> </module>
Example:
class Test {} // ok
interface testInterface{} // ok
class anotherTest {
int a=4; // 2 violations, '=' is not followed and preceded by whitespace.
}
To configure the check to allow empty loop bodies:
<module name="WhitespaceAround"> <property name="allowEmptyLoops" value="true"/> </module>
Example:
class Test {
public static void main(String[] args) {
for (int i = 100;i > 10; i--){} // ok
do {} while (i = 1); // ok
int a=4; // 2 violations, '=' is not followed and preceded by whitespace.
}
}
To configure the check to allow empty lambda bodies:
<module name="WhitespaceAround"> <property name="allowEmptyLambdas" value="true"/> </module>
Example:
class Test {
public static void main(String[] args) {
Runnable noop = () -> {}; // ok
int a=4; // 2 violations, '=' is not followed and preceded by whitespace.
}
}
To configure the check to allow empty catch bodies:
<module name="WhitespaceAround"> <property name="allowEmptyCatches" value="true"/> </module>
Example:
class Test {
public static void main(String[] args) {
int a=4; // 2 violations, '=' is not followed and preceded by whitespace.
try {
// body
} catch (Exception e){} // ok
}
}
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="false" /> </module>
Example:
class Test {
public static void main(String[] args) {
int a=4; // 2 violations , '=' is not followed and preceded by whitespace.
char[] vowels = {'a', 'e', 'i', 'o', 'u'};
for (char item: vowels) { // violation, ':' is not preceded by whitespace.
// body
}
}
}
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
ws.notFollowed
ws.notPreceded
AutomaticBean.OutputStreamOptions| Modifier and Type | Field and Description |
|---|---|
static String |
MSG_WS_NOT_FOLLOWED
A key is pointing to the warning message text in "messages.properties"
file.
|
static String |
MSG_WS_NOT_PRECEDED
A key is pointing to the warning message text in "messages.properties"
file.
|
| Constructor and Description |
|---|
WhitespaceAroundCheck() |
| 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.
|
beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokensfinishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverityconfigure, contextualize, getConfiguration, setupChildpublic static final String MSG_WS_NOT_PRECEDED
public static final String MSG_WS_NOT_FOLLOWED
public WhitespaceAroundCheck()
public int[] getDefaultTokens()
AbstractCheckgetDefaultTokens in class AbstractCheckTokenTypespublic int[] getAcceptableTokens()
AbstractCheckgetAcceptableTokens in class AbstractCheckTokenTypespublic int[] getRequiredTokens()
AbstractCheckgetRequiredTokens in class AbstractCheckTokenTypespublic void setAllowEmptyMethods(boolean allow)
allow - true to allow empty method bodies.public void setAllowEmptyConstructors(boolean allow)
allow - true to allow empty constructor bodies.public void setIgnoreEnhancedForColon(boolean ignore)
ignore - true to ignore enhanced for colon.public void setAllowEmptyTypes(boolean allow)
allow - true to allow empty type bodies.public void setAllowEmptyLoops(boolean allow)
allow - true to allow empty loops bodies.public void setAllowEmptyLambdas(boolean allow)
allow - true to allow empty lambda expressions.public void setAllowEmptyCatches(boolean allow)
allow - true to allow empty catch blocks.public void visitToken(DetailAST ast)
AbstractCheckvisitToken in class AbstractCheckast - the token to processCopyright © 2001–2020. All rights reserved.