com.puppycrawl.tools.checkstyle.checks.design

Class MutableExceptionCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.Check

com.puppycrawl.tools.checkstyle.checks.AbstractFormatCheck

com.puppycrawl.tools.checkstyle.checks.design.MutableExceptionCheck

All Implemented Interfaces:

Configurable, Contextualizable

public final class MutableExceptionCheck
extends AbstractFormatCheck

Ensures that exceptions (defined as any class name conforming to some regular expression) are immutable. That is, have only final fields.

Rationale: Exception instances should represent an error condition. Having non final fields not only allows the state to be modified by accident and therefore mask the original condition but also allows developers to accidentally forget to initialise state thereby leading to code catching the exception to draw incorrect conclusions based on the state.

Author:

Simon Harris

Constructor Summary

Constructors

Constructor and Description
MutableExceptionCheck() Creates new instance of the check.

Method Summary

Methods

Modifier and Type	Method and Description
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 aAST) Called after all the child nodes have been process.
void	visitToken(DetailAST aAST) Called to process a token.

Methods inherited from class com.puppycrawl.tools.checkstyle.checks.AbstractFormatCheck

getFormat, getRegexp, setCompileFlags, setFormat

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

beginTree, destroy, finishTree, getAcceptableTokens, getClassLoader, getFileContents, getLines, getTabWidth, getTokenNames, init, 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

Constructor Detail

MutableExceptionCheck

public MutableExceptionCheck()

Creates new instance of the check.

Method Detail

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: Check

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 Check

Returns:

the default tokens

See Also:

TokenTypes

getRequiredTokens

public int[] getRequiredTokens()

Description copied from class: Check

The tokens that this check must be registered for.

Overrides:

getRequiredTokens in class Check

Returns:

the token set this must be registered for.

See Also:

TokenTypes

visitToken

public void visitToken(DetailAST aAST)

Description copied from class: Check

Called to process a token.

Overrides:

visitToken in class Check

Parameters:

aAST - the token to process

leaveToken

public void leaveToken(DetailAST aAST)

Description copied from class: Check

Called after all the child nodes have been process.

Overrides:

leaveToken in class Check

Parameters:

aAST - the token leaving