Class SimplifyBooleanExpressionCheck
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.coding.SimplifyBooleanExpressionCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks for over-complicated boolean expressions. Currently finds code like
if (b == true)
, b || true
, !false
,
etc.
Rationale: Complex boolean logic makes code hard to understand and maintain.
To configure the check:
<module name="SimplifyBooleanExpression"/>
Example:
public class Test { public void bar() { boolean a, b; Foo c, d, e; if (!false) {}; // violation, can be simplified to true if (a == true) {}; // violation, can be simplified to a if (a == b) {}; // OK if (a == false) {}; // violation, can be simplified to !a if (!(a != true)) {}; // violation, can be simplified to a e = (a || b) ? c : d; // OK e = (a || false) ? c : d; // violation, can be simplified to a e = (a && b) ? c : d; // OK } }
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
simplify.expression
- 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
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
A key is pointing to the warning message text in "messages.properties" file.- See Also:
-
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Constructor Details
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SimplifyBooleanExpressionCheck
public SimplifyBooleanExpressionCheck()
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Method Details
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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:
-
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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