com.puppycrawl.tools.checkstyle.checks.metrics

Class CyclomaticComplexityCheck

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.metrics.CyclomaticComplexityCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class CyclomaticComplexityCheck
extends AbstractCheck

Checks cyclomatic complexity against a specified limit. The complexity is measured by the number of "if", "while", "do", "for", "?:", "catch", "switch", "case", "&&" and "||" statements (plus one) in the body of the member. It is a measure of the minimum number of possible paths through the source and therefore the number of required tests. Generally 1-4 is considered good, 5-7 ok, 8-10 consider re-factoring, and 11+ re-factor now!

Check has following properties:

switchBlockAsSingleDecisionPoint - controls whether to treat the whole switch block as a single decision point. Default value is false

Field Summary

Fields

Modifier and Type	Field and Description
private java.math.BigInteger	currentValue The current value.
private static int	DEFAULT_COMPLEXITY_VALUE Default allowed complexity.
private static java.math.BigInteger	INITIAL_VALUE The initial current value.
private int	max Threshold to report error for.
static java.lang.String	MSG_KEY A key is pointing to the warning message text in "messages.properties" file.
private boolean	switchBlockAsSingleDecisionPoint Whether to treat the whole switch block as a single decision point.
private java.util.Deque<java.math.BigInteger>	valueStack Stack of values - all but the current value.

Constructor Summary

Constructors

Constructor and Description
CyclomaticComplexityCheck()

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.
protected void	incrementCurrentValue(java.math.BigInteger amount) Increments the current value by a specified amount.
private void	leaveMethodDef(DetailAST ast) Process the end of a method definition.
void	leaveToken(DetailAST ast) Called after all the child nodes have been process.
protected java.math.BigInteger	popValue() Pops a value off the stack and makes it the current value.
protected void	pushValue() Push the current value on the stack.
void	setMax(int max) Set the maximum threshold allowed.
void	setSwitchBlockAsSingleDecisionPoint(boolean switchBlockAsSingleDecisionPoint) Sets whether to treat the whole switch block as a single decision point.
private void	visitMethodDef() Process the start of the method definition.
void	visitToken(DetailAST ast) Called to process a token.
protected void	visitTokenHook(DetailAST ast) Hook called when visiting a token.

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

beginTree, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getTabWidth, getTokenNames, init, isCommentNodesRequired, 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

INITIAL_VALUE

private static final java.math.BigInteger INITIAL_VALUE

The initial current value.

DEFAULT_COMPLEXITY_VALUE

private static final int DEFAULT_COMPLEXITY_VALUE

Default allowed complexity.

See Also:

Constant Field Values

valueStack

private final java.util.Deque<java.math.BigInteger> valueStack

Stack of values - all but the current value.

switchBlockAsSingleDecisionPoint

private boolean switchBlockAsSingleDecisionPoint

Whether to treat the whole switch block as a single decision point.

currentValue

private java.math.BigInteger currentValue

The current value.

max

private int max

Threshold to report error for.

Constructor Detail

CyclomaticComplexityCheck

public CyclomaticComplexityCheck()

Method Detail

setSwitchBlockAsSingleDecisionPoint

public void setSwitchBlockAsSingleDecisionPoint(boolean switchBlockAsSingleDecisionPoint)

Sets whether to treat the whole switch block as a single decision point.

Parameters:

switchBlockAsSingleDecisionPoint - whether to treat the whole switch block as a single decision point.

setMax

public final void setMax(int max)

Set the maximum threshold allowed.

Parameters:

max - the maximum threshold

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 final 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

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

visitTokenHook

protected final void visitTokenHook(DetailAST ast)

Hook called when visiting a token. Will not be called the method definition tokens.

Parameters:

ast - the token being visited

leaveMethodDef

private void leaveMethodDef(DetailAST ast)

Process the end of a method definition.

Parameters:

ast - the token representing the method definition

incrementCurrentValue

protected final void incrementCurrentValue(java.math.BigInteger amount)

Increments the current value by a specified amount.

Parameters:

amount - the amount to increment by

pushValue

protected final void pushValue()

Push the current value on the stack.

popValue

protected final java.math.BigInteger popValue()

Pops a value off the stack and makes it the current value.

Returns:

pop a value off the stack and make it the current value

visitMethodDef

private void visitMethodDef()

Process the start of the method definition.