Class EmptyBlockCheck
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.blocks.EmptyBlockCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks for empty blocks. This check does not validate sequential blocks.
Sequential blocks won't be checked. Also, no violations for fallthrough:
switch (a) { case 1: // no violation case 2: // no violation case 3: someMethod(); { } // no violation default: break; }
NOTE: This check processes LITERAL_CASE and LITERAL_DEFAULT separately.
Verification empty block is done for single most nearest case
or default
.
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Property
option
- specify the policy on block contents. Type iscom.puppycrawl.tools.checkstyle.checks.blocks.BlockOption
. Default value isstatement
. -
Property
tokens
- tokens to check Type isjava.lang.String[]
. Validation type istokenSet
. Default value is: LITERAL_WHILE, LITERAL_TRY, LITERAL_FINALLY, LITERAL_DO, LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, INSTANCE_INIT, STATIC_INIT, LITERAL_SWITCH, LITERAL_SYNCHRONIZED.
To configure the check:
<module name="EmptyBlock"/>
To configure the check for the text
policy and only try
blocks:
<module name="EmptyBlock"> <property name="option" value="text"/> <property name="tokens" value="LITERAL_TRY"/> </module>
To configure the check for default in switch block:
<module name="EmptyBlock"> <property name="tokens" value="LITERAL_DEFAULT"/> </module>
Result:
switch (a) { default: // no violation for "default:" as empty block belong to "case 1:" case 1: { } }
switch (a) { case 1: default: { } // violation }
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
block.empty
-
block.noStatement
- Since:
- 3.0
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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
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint[]
The configurable token set.int[]
Returns the default token a check is interested in.int[]
The tokens that this check must be registered for.void
Setter to specify the policy on block contents.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
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Field Details
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MSG_KEY_BLOCK_NO_STATEMENT
A key is pointing to the warning message text in "messages.properties" file.- See Also:
-
MSG_KEY_BLOCK_EMPTY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
-
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Constructor Details
-
EmptyBlockCheck
public EmptyBlockCheck()
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Method Details
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setOption
Setter to specify the policy on block contents.- Parameters:
optionStr
- string to decode option from- Throws:
IllegalArgumentException
- if unable to decode
-
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:
-
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:
-
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:
-
visitToken
Description copied from class:AbstractCheck
Called to process a token.- Overrides:
visitToken
in classAbstractCheck
- Parameters:
ast
- the token to process
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