com.puppycrawl.tools.checkstyle.checks.coding

Class RequireThisCheck

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.RequireThisCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class RequireThisCheck
extends AbstractCheck

Checks that code doesn't rely on the "this" default. That is references to instance variables and methods of the present object are explicitly of the form "this.varName" or "this.methodName(args)".

Check has the following options:

checkFields - whether to check references to fields. Default value is true.

checkMethods - whether to check references to methods. Default value is true.

validateOnlyOverlapping - whether to check only overlapping by variables or arguments. Default value is true.

Warning: the Check is very controversial if 'validateOnlyOverlapping' option is set to 'false' and not that actual nowadays.

Examples of use:

 <module name="RequireThis"/>
 

An example of how to configure to check this qualifier for methods only:

 <module name="RequireThis">
   <property name="checkFields" value="false"/>
   <property name="checkMethods" value="true"/>
 </module>
 

Rationale:

1. The same notation/habit for C++ and Java (C++ have global methods, so having "this." do make sense in it to distinguish call of method of class instead of global).
2. Non-IDE development (ease of refactoring, some clearness to distinguish static and non-static methods).

Limitations: Nothing is currently done about static variables or catch-blocks. Static methods invoked on a class name seem to be OK; both the class name and the method name have a DOT parent. Non-static methods invoked on either this or a variable name seem to be OK, likewise.

Author:

Stephen Bloch, o_sukhodolsky, Andrei Selkin

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RequireThisCheck.CatchFrame A frame initiated on entering a catch block; holds local catch variable names.
static class	RequireThisCheck.ForFrame A frame initiated on entering a for block; holds local for variable names.

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

AutomaticBean.OutputStreamOptions

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
RequireThisCheck()

Method Summary

Modifier and Type	Method and Description
void	beginTree(DetailAST rootAST) Called before the starting to process a tree.
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.
void	leaveToken(DetailAST ast) Called after all the child nodes have been process.
void	setCheckFields(boolean checkFields) Setter for checkFields property.
void	setCheckMethods(boolean checkMethods) Setter for checkMethods property.
void	setValidateOnlyOverlapping(boolean validateOnlyOverlapping) Setter for validateOnlyOverlapping property.
void	visitToken(DetailAST ast) Called to process a token.

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

clearMessages, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, log, log, log, setClassLoader, 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

Methods inherited from class java.lang.Object

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

Field Detail

MSG_METHOD

public static final String MSG_METHOD

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

See Also:

Constant Field Values

MSG_VARIABLE

public static final String MSG_VARIABLE

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

See Also:

Constant Field Values

Constructor Detail

RequireThisCheck

public RequireThisCheck()

Method Detail

setCheckFields

public void setCheckFields(boolean checkFields)

Setter for checkFields property.

Parameters:

checkFields - should we check fields usage or not.

setCheckMethods

public void setCheckMethods(boolean checkMethods)

Setter for checkMethods property.

Parameters:

checkMethods - should we check methods usage or not.

setValidateOnlyOverlapping

public void setValidateOnlyOverlapping(boolean validateOnlyOverlapping)

Setter for validateOnlyOverlapping property.

Parameters:

validateOnlyOverlapping - should we check only overlapping by variables or arguments.

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

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

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

beginTree

public void beginTree(DetailAST rootAST)

Description copied from class: AbstractCheck

Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.

Overrides:

beginTree in class AbstractCheck

Parameters:

rootAST - the root of the tree

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

leaveToken

public void leaveToken(DetailAST ast)

Description copied from class: AbstractCheck

Called after all the child nodes have been process.

Overrides:

leaveToken in class AbstractCheck

Parameters:

ast - the token leaving