Class JavaNCSSCheck
- 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.JavaNCSSCheck
-
- All Implemented Interfaces:
Configurable
,Contextualizable
public class JavaNCSSCheck extends AbstractCheck
Determines complexity of methods, classes and files by counting the Non Commenting Source Statements (NCSS). This check adheres to the specification for the JavaNCSS-Tool written by Chr. Clemens Lee.
Roughly said the NCSS metric is calculated by counting the source lines which are not comments, (nearly) equivalent to counting the semicolons and opening curly braces.
The NCSS for a class is summarized from the NCSS of all its methods, the NCSS of its nested classes and the number of member variable declarations.
The NCSS for a file is summarized from the ncss of all its top level classes, the number of imports and the package declaration.
Rationale: Too large methods and classes are hard to read and costly to maintain. A large NCSS number often means that a method or class has too many responsibilities and/or functionalities which should be decomposed into smaller units.
-
Property
methodMaximum
- Specify the maximum allowed number of non commenting lines in a method. Default value is50
. -
Property
classMaximum
- Specify the maximum allowed number of non commenting lines in a class. Default value is1500
. -
Property
fileMaximum
- Specify the maximum allowed number of non commenting lines in a file including all top level and nested classes. Default value is2000
.
To configure the check:
<module name="JavaNCSS"/>
To configure the check with 40 allowed non commenting lines for a method:
<module name="JavaNCSS"> <property name="methodMaximum" value="40"/> </module>
- Since:
- 3.5
-
-
Nested Class Summary
-
Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
-
-
Field Summary
Fields Modifier and Type Field Description static java.lang.String
MSG_CLASS
A key is pointing to the warning message text in "messages.properties" file.static java.lang.String
MSG_FILE
A key is pointing to the warning message text in "messages.properties" file.static java.lang.String
MSG_METHOD
A key is pointing to the warning message text in "messages.properties" file.
-
Constructor Summary
Constructors Constructor Description JavaNCSSCheck()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
beginTree(DetailAST rootAST)
Called before the starting to process a tree.void
finishTree(DetailAST rootAST)
Called after finished processing 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
setClassMaximum(int classMaximum)
Setter to specify the maximum allowed number of non commenting lines in a class.void
setFileMaximum(int fileMaximum)
Setter to specify the maximum allowed number of non commenting lines in a file including all top level and nested classes.void
setMethodMaximum(int methodMaximum)
Setter to specify the maximum allowed number of non commenting lines in a method.void
visitToken(DetailAST ast)
Called to process a token.-
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
clearMessages, destroy, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, 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.api.AutomaticBean
configure, contextualize, getConfiguration, setupChild
-
-
-
-
Field Detail
-
MSG_METHOD
public static final java.lang.String MSG_METHOD
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
-
MSG_CLASS
public static final java.lang.String MSG_CLASS
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
-
MSG_FILE
public static final java.lang.String MSG_FILE
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
-
-
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 classAbstractCheck
- 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 classAbstractCheck
- 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 classAbstractCheck
- 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 classAbstractCheck
- 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 classAbstractCheck
- 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 classAbstractCheck
- Parameters:
ast
- the token leaving
-
finishTree
public void finishTree(DetailAST rootAST)
Description copied from class:AbstractCheck
Called after finished processing a tree. Ideal place to report on information collected whilst processing a tree.- Overrides:
finishTree
in classAbstractCheck
- Parameters:
rootAST
- the root of the tree
-
setFileMaximum
public void setFileMaximum(int fileMaximum)
Setter to specify the maximum allowed number of non commenting lines in a file including all top level and nested classes.- Parameters:
fileMaximum
- the maximum ncss
-
setClassMaximum
public void setClassMaximum(int classMaximum)
Setter to specify the maximum allowed number of non commenting lines in a class.- Parameters:
classMaximum
- the maximum ncss
-
setMethodMaximum
public void setMethodMaximum(int methodMaximum)
Setter to specify the maximum allowed number of non commenting lines in a method.- Parameters:
methodMaximum
- the maximum ncss
-
-