Class DescendantTokenCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks for restricted tokens beneath other tokens.
WARNING: This is a very powerful and flexible check, but, at the same time, it is low-level and very implementation-dependent because its results depend on the grammar we use to build abstract syntax trees. Thus we recommend using other checks when they provide the desired functionality. Essentially, this check just works on the level of an abstract syntax tree and knows nothing about language structures.
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Property
limitedTokens
- Specify set of tokens with limited occurrences as descendants. Type isjava.lang.String[]
. Validation type istokenTypesSet
. Default value is""
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Property
minimumDepth
- Specify the minimum depth for descendant counts. Type isint
. Default value is0
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Property
maximumDepth
- Specify the maximum depth for descendant counts. Type isint
. Default value is2147483647
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Property
minimumNumber
- Specify a minimum count for descendants. Type isint
. Default value is0
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Property
maximumNumber
- Specify a maximum count for descendants. Type isint
. Default value is2147483647
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Property
sumTokenCounts
- Control whether the number of tokens found should be calculated from the sum of the individual token counts. Type isboolean
. Default value isfalse
. -
Property
minimumMessage
- Define the violation message when the minimum count is not reached. Type isjava.lang.String
. Default value isnull
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Property
maximumMessage
- Define the violation message when the maximum count is exceeded. Type isjava.lang.String
. Default value isnull
. -
Property
tokens
- tokens to check Type isanyTokenTypesSet
. Default value isempty
.
To configure the check to produce a violation on a switch statement with no default case:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_SWITCH"/> <property name="maximumDepth" value="2"/> <property name="limitedTokens" value="LITERAL_DEFAULT"/> <property name="minimumNumber" value="1"/> </module>
To configure the check to produce a violation on a condition in for
which performs no check:
<module name="DescendantToken"> <property name="tokens" value="FOR_CONDITION"/> <property name="limitedTokens" value="EXPR"/> <property name="minimumNumber" value="1"/> </module>
To configure the check to produce a violation on comparing this
with
null
(i.e. this == null
and this != null
):
<module name="DescendantToken"> <property name="tokens" value="EQUAL,NOT_EQUAL"/> <property name="limitedTokens" value="LITERAL_THIS,LITERAL_NULL"/> <property name="maximumNumber" value="1"/> <property name="maximumDepth" value="1"/> <property name="sumTokenCounts" value="true"/> </module>
To configure the check to produce a violation on a String
literal equality check:
<module name="DescendantToken"> <property name="tokens" value="EQUAL,NOT_EQUAL"/> <property name="limitedTokens" value="STRING_LITERAL"/> <property name="maximumNumber" value="0"/> <property name="maximumDepth" value="1"/> </module>
To configure the check to produce a violation on an assert statement that may have side effects (formatted for browser display):
<module name="DescendantToken"> <property name="tokens" value="LITERAL_ASSERT"/> <property name="limitedTokens" value="ASSIGN,DEC,INC,POST_DEC, POST_INC,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,DIV_ASSIGN,MOD_ASSIGN, BSR_ASSIGN,SR_ASSIGN,SL_ASSIGN,BAND_ASSIGN,BXOR_ASSIGN,BOR_ASSIGN, METHOD_CALL"/> <property name="maximumNumber" value="0"/> </module>
To configure the check to produce a violation on an initializer in for
performs no setup (where a while
statement could be used instead):
<module name="DescendantToken"> <property name="tokens" value="FOR_INIT"/> <property name="limitedTokens" value="EXPR"/> <property name="minimumNumber" value="1"/> </module>
To configure the check to produce a violation on a switch that is nested in another switch:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_SWITCH"/> <property name="limitedTokens" value="LITERAL_SWITCH"/> <property name="maximumNumber" value="0"/> <property name="minimumDepth" value="1"/> </module>
To configure the check to produce a violation on a return statement from within a catch or finally block:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_FINALLY,LITERAL_CATCH"/> <property name="limitedTokens" value="LITERAL_RETURN"/> <property name="maximumNumber" value="0"/> </module>
To configure the check to produce a violation on a try statement within a catch or finally block:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_CATCH,LITERAL_FINALLY"/> <property name="limitedTokens" value="LITERAL_TRY"/> <property name="maximumNumber" value="0"/> </module>
To configure the check to produce a violation on a switch with too many cases:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_SWITCH"/> <property name="limitedTokens" value="LITERAL_CASE"/> <property name="maximumDepth" value="2"/> <property name="maximumNumber" value="10"/> </module>
To configure the check to produce a violation on a method with too many local variables:
<module name="DescendantToken"> <property name="tokens" value="METHOD_DEF"/> <property name="limitedTokens" value="VARIABLE_DEF"/> <property name="maximumDepth" value="2"/> <property name="maximumNumber" value="10"/> </module>
To configure the check to produce a violation on a method with too many returns:
<module name="DescendantToken"> <property name="tokens" value="METHOD_DEF"/> <property name="limitedTokens" value="LITERAL_RETURN"/> <property name="maximumNumber" value="3"/> </module>
To configure the check to produce a violation on an interface with too many fields:
<module name="DescendantToken"> <property name="tokens" value="INTERFACE_DEF"/> <property name="limitedTokens" value="VARIABLE_DEF"/> <property name="maximumDepth" value="2"/> <property name="maximumNumber" value="0"/> </module>
To configure the check to produce a violation on a method which throws too many exceptions:
<module name="DescendantToken"> <property name="tokens" value="LITERAL_THROWS"/> <property name="limitedTokens" value="IDENT"/> <property name="maximumNumber" value="1"/> </module>
To configure the check to produce a violation on a method with too many expressions:
<module name="DescendantToken"> <property name="tokens" value="METHOD_DEF"/> <property name="limitedTokens" value="EXPR"/> <property name="maximumNumber" value="200"/> </module>
To configure the check to produce a violation on an empty statement:
<module name="DescendantToken"> <property name="tokens" value="EMPTY_STAT"/> <property name="limitedTokens" value="EMPTY_STAT"/> <property name="maximumNumber" value="0"/> <property name="maximumDepth" value="0"/> <property name="maximumMessage" value="Empty statement is not allowed."/> </module>
To configure the check to produce a violation on a class with too many fields:
<module name="DescendantToken"> <property name="tokens" value="CLASS_DEF"/> <property name="limitedTokens" value="VARIABLE_DEF"/> <property name="maximumDepth" value="2"/> <property name="maximumNumber" value="10"/> </module>
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
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descendant.token.max
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descendant.token.min
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descendant.token.sum.max
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descendant.token.sum.min
- Since:
- 3.2
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Nested Class Summary
Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
A key is pointing to the warning message text in "messages.properties" file.static final String
A key is pointing to the warning message text in "messages.properties" file.static final String
A key is pointing to the warning message text in "messages.properties" file.static final String
A key is pointing to the warning message text in "messages.properties" file. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint[]
The configurable token set.int[]
Returns the default token a check is interested in.int[]
The tokens that this check must be registered for.void
setLimitedTokens
(String... limitedTokensParam) Setter to specify set of tokens with limited occurrences as descendants.void
setMaximumDepth
(int maximumDepth) Setter to specify the maximum depth for descendant counts.void
setMaximumMessage
(String message) Setter to define the violation message when the maximum count is exceeded.void
setMaximumNumber
(int maximumNumber) Setter to specify a maximum count for descendants.void
setMinimumDepth
(int minimumDepth) Setter to specify the minimum depth for descendant counts.void
setMinimumMessage
(String message) Setter to define the violation message when the minimum count is not reached.void
setMinimumNumber
(int minimumNumber) Setter to specify a minimum count for descendants.void
setSumTokenCounts
(boolean sum) Setter to control whether the number of tokens found should be calculated from the sum of the individual token counts.void
visitToken
(DetailAST ast) Called to process a token.Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, 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
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Field Details
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MSG_KEY_MIN
A key is pointing to the warning message text in "messages.properties" file.- See Also:
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MSG_KEY_MAX
A key is pointing to the warning message text in "messages.properties" file.- See Also:
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MSG_KEY_SUM_MIN
A key is pointing to the warning message text in "messages.properties" file.- See Also:
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MSG_KEY_SUM_MAX
A key is pointing to the warning message text in "messages.properties" file.- See Also:
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Constructor Details
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DescendantTokenCheck
public DescendantTokenCheck()
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Method Details
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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:
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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:
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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:
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visitToken
Description copied from class:AbstractCheck
Called to process a token.- Overrides:
visitToken
in classAbstractCheck
- Parameters:
ast
- the token to process
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setLimitedTokens
Setter to specify set of tokens with limited occurrences as descendants.- Parameters:
limitedTokensParam
- - list of tokens to ignore.
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setMinimumDepth
public void setMinimumDepth(int minimumDepth) Setter to specify the minimum depth for descendant counts.- Parameters:
minimumDepth
- the minimum depth for descendant counts.
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setMaximumDepth
public void setMaximumDepth(int maximumDepth) Setter to specify the maximum depth for descendant counts.- Parameters:
maximumDepth
- the maximum depth for descendant counts.
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setMinimumNumber
public void setMinimumNumber(int minimumNumber) Setter to specify a minimum count for descendants.- Parameters:
minimumNumber
- the minimum count for descendants.
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setMaximumNumber
public void setMaximumNumber(int maximumNumber) Setter to specify a maximum count for descendants.- Parameters:
maximumNumber
- the maximum count for descendants.
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setMinimumMessage
Setter to define the violation message when the minimum count is not reached.- Parameters:
message
- the violation message for minimum count not reached. Used as aMessageFormat
pattern with arguments- {0} - token count
- {1} - minimum number
- {2} - name of token
- {3} - name of limited token
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setMaximumMessage
Setter to define the violation message when the maximum count is exceeded.- Parameters:
message
- the violation message for maximum count exceeded. Used as aMessageFormat
pattern with arguments- {0} - token count
- {1} - maximum number
- {2} - name of token
- {3} - name of limited token
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setSumTokenCounts
public void setSumTokenCounts(boolean sum) Setter to control whether the number of tokens found should be calculated from the sum of the individual token counts.- Parameters:
sum
- whether to use the sum.
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