Class AvoidStaticImportCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks that there are no static import statements.
Rationale: Importing static members can lead to naming conflicts between class' members. It may lead to poor code readability since it may no longer be clear what class a member resides in (without looking at the import statement).
If you exclude a starred import on a class this automatically excludes each member individually.
For example: Excluding java.lang.Math.*
. will allow the import
of each static member in the Math class individually like
java.lang.Math.PI, java.lang.Math.cos, ...
.
-
Property
excludes
- Control whether to allow for certain classes via a star notation to be excluded such asjava.lang.Math.*
or specific static members to be excluded likejava.lang.System.out
for a variable orjava.lang.Math.random
for a method. See notes section for details. Type isjava.lang.String[]
. Default value is""
.
To configure the check:
<module name="AvoidStaticImport"/>
Example:
import static java.lang.Math.pow; // violation import static java.lang.System.*; // violation import java.io.File; // OK import java.util.*; // OK
To configure the check so that the java.lang.System.out
member and all
members from java.lang.Math
are allowed:
<module name="AvoidStaticImport"> <property name="excludes" value="java.lang.System.out,java.lang.Math.*"/> </module>
Example:
import static java.lang.Math.*; // OK import static java.lang.System.out; // OK import static java.lang.Integer.parseInt; // violation import java.io.*; // OK import java.util.*; // OK
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
import.avoidStatic
- Since:
- 5.0
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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 TypeFieldDescriptionprivate String[]
Control whether to allow for certain classes via a star notation to be excluded such asjava.lang.Math.*
or specific static members to be excluded likejava.lang.System.out
for a variable orjava.lang.Math.random
for a method.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.private boolean
Checks if a class or static member is exempt from known excludes.private static boolean
isStarImportOfPackage
(String classOrStaticMember, String exclude) Returns true if classOrStaticMember is a starred name of package, not just member name.void
setExcludes
(String... excludes) Setter to control whether to allow for certain classes via a star notation to be excluded such asjava.lang.Math.*
or specific static members to be excluded likejava.lang.System.out
for a variable orjava.lang.Math.random
for a method.void
visitToken
(DetailAST ast) Called to process a token.Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearViolations, destroy, finishTree, getFileContents, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, 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
-
MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
-
excludes
Control whether to allow for certain classes via a star notation to be excluded such asjava.lang.Math.*
or specific static members to be excluded likejava.lang.System.out
for a variable orjava.lang.Math.random
for a method. See notes section for details.
-
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Constructor Details
-
AvoidStaticImportCheck
public AvoidStaticImportCheck()
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Method Details
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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:
-
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:
-
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:
-
setExcludes
Setter to control whether to allow for certain classes via a star notation to be excluded such asjava.lang.Math.*
or specific static members to be excluded likejava.lang.System.out
for a variable orjava.lang.Math.random
for a method. See notes section for details.- Parameters:
excludes
- a list of fully-qualified class names/specific static members where static imports are ok
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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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isExempt
Checks if a class or static member is exempt from known excludes.- Parameters:
classOrStaticMember
- the class or static member- Returns:
- true if except false if not
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isStarImportOfPackage
Returns true if classOrStaticMember is a starred name of package, not just member name.- Parameters:
classOrStaticMember
- - full name of memberexclude
- - current exclusion- Returns:
- true if member in exclusion list
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