Package com.puppycrawl.tools.checkstyle.checks

Class FinalParametersCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.FinalParametersCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class FinalParametersCheck
extends AbstractCheck

Checks that parameters for methods, constructors, catch and for-each blocks are final. Interface, abstract, and native methods are not checked: the final keyword does not make sense for interface, abstract, and native method parameters as there is no code that could modify the parameter.

Rationale: Changing the value of parameters during the execution of the method's algorithm can be confusing and should be avoided. A great way to let the Java compiler prevent this coding style is to declare parameters final.

• Property ignorePrimitiveTypes - Ignore primitive types as parameters. Type is boolean. Default value is false.
• Property ignoreUnnamedParameters - Ignore unnamed parameters. Type is boolean. Default value is true.
• Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: METHOD_DEF, CTOR_DEF.

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

• final.parameter

Since:

3.0

Nested Class Summary

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

AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	ignorePrimitiveTypes	Ignore primitive types as parameters.
private boolean	ignoreUnnamedParameters	Ignore unnamed parameters.
static final String	MSG_KEY	A key is pointing to the warning message text in "messages.properties" file.
private final BitSet	primitiveDataTypes	Contains primitive datatypes.

Constructor Summary

Constructors

Constructor	Description
FinalParametersCheck()

Method Summary

Modifier and Type	Method	Description
private void	checkParam(DetailAST param)	Checks if the given parameter is final.
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 boolean	isIgnoredPrimitiveParam(DetailAST paramDef)	Checks for skip current param due to ignorePrimitiveTypes option.
private boolean	isIgnoredUnnamedParam(DetailAST paramDef)	Checks for skip current param due to ignoreUnnamedParameters option.
void	setIgnorePrimitiveTypes(boolean ignorePrimitiveTypes)	Setter to ignore primitive types as parameters.
void	setIgnoreUnnamedParameters(boolean ignoreUnnamedParameters)	Setter to ignore unnamed parameters.
private void	visitCatch(DetailAST catchClause)	Checks parameter of the catch block.
private void	visitForEachClause(DetailAST forEachClause)	Checks parameter of the for each clause.
private void	visitMethod(DetailAST method)	Checks parameters of the method or ctor.
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

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.AbstractAutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Details

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

primitiveDataTypes

private final BitSet primitiveDataTypes

Contains primitive datatypes.

ignorePrimitiveTypes

private boolean ignorePrimitiveTypes

Ignore primitive types as parameters.

ignoreUnnamedParameters

private boolean ignoreUnnamedParameters

Ignore unnamed parameters.

Constructor Details

FinalParametersCheck

public FinalParametersCheck()

Method Details

setIgnorePrimitiveTypes

public void setIgnorePrimitiveTypes(boolean ignorePrimitiveTypes)

Setter to ignore primitive types as parameters.

Parameters:

ignorePrimitiveTypes - true or false.

Since:

6.2

setIgnoreUnnamedParameters

public void setIgnoreUnnamedParameters(boolean ignoreUnnamedParameters)

Setter to ignore unnamed parameters.

Parameters:

ignoreUnnamedParameters - true or false.

Since:

10.18.0

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

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

visitMethod

private void visitMethod(DetailAST method)

Checks parameters of the method or ctor.

Parameters:

method - method or ctor to check.

visitCatch

private void visitCatch(DetailAST catchClause)

Checks parameter of the catch block.

Parameters:

catchClause - catch block to check.

visitForEachClause

private void visitForEachClause(DetailAST forEachClause)

Checks parameter of the for each clause.

Parameters:

forEachClause - for each clause to check.

checkParam

private void checkParam(DetailAST param)

Checks if the given parameter is final.

Parameters:

param - parameter to check.

isIgnoredPrimitiveParam

private boolean isIgnoredPrimitiveParam(DetailAST paramDef)

Checks for skip current param due to ignorePrimitiveTypes option.

Parameters:

paramDef - PARAMETER_DEF

Returns:

true if param has to be skipped.

isIgnoredUnnamedParam

private boolean isIgnoredUnnamedParam(DetailAST paramDef)

Checks for skip current param due to ignoreUnnamedParameters option.

Parameters:

paramDef - parameter to check

Returns:

true if the parameter should be skipped due to the ignoreUnnamedParameters option.