Class ExplicitInitializationCheck
- java.lang.Object
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- com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
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- com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
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- com.puppycrawl.tools.checkstyle.api.AbstractCheck
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- com.puppycrawl.tools.checkstyle.checks.coding.ExplicitInitializationCheck
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- All Implemented Interfaces:
Configurable
,Contextualizable
public class ExplicitInitializationCheck extends AbstractCheck
Checks if any class or object member is explicitly initialized to default for its type value (
null
for object references, zero for numeric types andchar
andfalse
forboolean
.Rationale: Each instance variable gets initialized twice, to the same value. Java initializes each instance variable to its default value (
0
ornull
) before performing any initialization specified in the code. So there is a minor inefficiency.-
Property
onlyObjectReferences
- Control whether only explicit initializations made to null for objects should be checked. Type isboolean
. Default value isfalse
.
Parent is
com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
explicit.init
- Since:
- 3.2
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Nested Class Summary
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Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
AbstractAutomaticBean.OutputStreamOptions
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Field Summary
Fields Modifier and Type Field Description static String
MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.private boolean
onlyObjectReferences
Control whether only explicit initializations made to null for objects should be checked.
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Constructor Summary
Constructors Constructor Description ExplicitInitializationCheck()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method 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.private static boolean
isNumericType(int type)
Determine if a given type is a numeric type.private static boolean
isSkipCase(DetailAST ast)
Checks for cases that should be skipped: no assignment, local variable, final variables.private static boolean
isZero(DetailAST expr)
Checks if given node contains numeric constant for zero.private static boolean
isZeroChar(DetailAST exprStart)
Examine char literal for initializing to default value.void
setOnlyObjectReferences(boolean onlyObjectReferences)
Setter to control whether only explicit initializations made to null for objects should be checked.private void
validateNonObjects(DetailAST ast)
Checks for explicit initializations made to 'false', '0' and '\0'.void
visitToken(DetailAST ast)
Called to process a token.-
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens
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Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity
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Methods inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
configure, contextualize, getConfiguration, setupChild
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Field Detail
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MSG_KEY
public static final String MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
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onlyObjectReferences
private boolean onlyObjectReferences
Control whether only explicit initializations made to null for objects should be checked.
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Constructor Detail
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ExplicitInitializationCheck
public ExplicitInitializationCheck()
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Method Detail
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getDefaultTokens
public final 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:
TokenTypes
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getRequiredTokens
public final 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:
TokenTypes
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getAcceptableTokens
public final 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:
TokenTypes
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setOnlyObjectReferences
public void setOnlyObjectReferences(boolean onlyObjectReferences)
Setter to control whether only explicit initializations made to null for objects should be checked.- Parameters:
onlyObjectReferences
- whether only explicit initialization made to null should be checked- Since:
- 7.8
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visitToken
public void visitToken(DetailAST ast)
Description copied from class:AbstractCheck
Called to process a token.- Overrides:
visitToken
in classAbstractCheck
- Parameters:
ast
- the token to process
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validateNonObjects
private void validateNonObjects(DetailAST ast)
Checks for explicit initializations made to 'false', '0' and '\0'.- Parameters:
ast
- token being checked for explicit initializations
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isZeroChar
private static boolean isZeroChar(DetailAST exprStart)
Examine char literal for initializing to default value.- Parameters:
exprStart
- expression- Returns:
- true is literal is initialized by zero symbol
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isSkipCase
private static boolean isSkipCase(DetailAST ast)
Checks for cases that should be skipped: no assignment, local variable, final variables.- Parameters:
ast
- Variable def AST- Returns:
- true is that is a case that need to be skipped.
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isNumericType
private static boolean isNumericType(int type)
Determine if a given type is a numeric type.- Parameters:
type
- code of the type for check.- Returns:
- true if it's a numeric type.
- See Also:
TokenTypes
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