com.puppycrawl.tools.checkstyle.checks.design

Class HideUtilityClassConstructorCheck

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.design.HideUtilityClassConstructorCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class HideUtilityClassConstructorCheck
extends AbstractCheck

Make sure that utility classes (classes that contain only static methods) do not have a public constructor.

Rationale: Instantiating utility classes does not make sense. A common mistake is forgetting to hide the default constructor.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	HideUtilityClassConstructorCheck.Details Details of class that are required for validation.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	MSG_KEY A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
HideUtilityClassConstructorCheck()

Method Summary

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.
private static boolean	isAbstract(DetailAST ast) Returns true if given class is abstract or false.
private static boolean	isStatic(DetailAST ast) Returns true if given class is static or false.
void	visitToken(DetailAST ast) Called to process a token.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

beginTree, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, setClassLoader, setFileContents, setMessages, setTabWidth, setTokens

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, log, setId, setSeverity

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

configure, contextualize, finishLocalSetup, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Detail

MSG_KEY

public static final java.lang.String MSG_KEY

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

Constructor Detail

HideUtilityClassConstructorCheck

public HideUtilityClassConstructorCheck()

Method Detail

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

isAbstract

private static boolean isAbstract(DetailAST ast)

Returns true if given class is abstract or false.

Parameters:

ast - class definition for check.

Returns:

true if a given class declared as abstract.

isStatic

private static boolean isStatic(DetailAST ast)

Returns true if given class is static or false.

Parameters:

ast - class definition for check.

Returns:

true if a given class declared as static.