Class AvoidStarImportCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks that there are no import statements that use the *
notation.
Rationale: Importing all classes from a package or static members from a class leads to tight coupling between packages or classes and might lead to problems when a new version of a library introduces name clashes.
Note that property excludes
is not recursive, subpackages of excluded
packages are not automatically excluded.
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Property
excludes
- Specify packages where star imports are allowed. Type isjava.lang.String[]
. Default value is""
. -
Property
allowClassImports
- Control whether to allow starred class imports likeimport java.util.*;
. Type isboolean
. Default value isfalse
. -
Property
allowStaticMemberImports
- Control whether to allow starred static member imports likeimport static org.junit.Assert.*;
. Type isboolean
. Default value isfalse
.
To configure the check:
<module name="AvoidStarImport"/>
Example:
import java.util.Scanner; // OK import java.io.*; // violation import static java.lang.Math.*; // violation import java.util.*; // violation import java.net.*; // violation
To configure the check so that star imports from packages
java.io and java.net
as well as static members from class
java.lang.Math
are allowed:
<module name="AvoidStarImport"> <property name="excludes" value="java.io,java.net,java.lang.Math"/> </module>
Example:
import java.util.Scanner; // OK import java.io.*; // OK import static java.lang.Math.*; // OK import java.util.*; // violation import java.net.*; // OK
To configure the check so that star imports from all packages are allowed:
<module name="AvoidStarImport"> <property name="allowClassImports" value="true"/> </module>
Example:
import java.util.Scanner; // OK import java.io.*; // OK import static java.lang.Math.*; // violation import java.util.*; // OK import java.net.*; // OK
To configure the check so that starred static member imports from all packages are allowed:
<module name="AvoidStarImport"> <property name="allowStaticMemberImports" value="true"/> </module>
Example:
import java.util.Scanner; // OK import java.io.*; // violation import static java.lang.Math.*; // OK import java.util.*; // violation import java.net.*; // violation
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
import.avoidStar
- Since:
- 3.0
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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
Fields -
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
setAllowClassImports
(boolean allow) Setter to control whether to allow starred class imports likeimport java.util.*;
.void
setAllowStaticMemberImports
(boolean allow) Setter to control whether to allow starred static member imports likeimport static org.junit.Assert.*;
.void
setExcludes
(String... excludesParam) Setter to specify packages where star imports are allowed.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
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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AvoidStarImportCheck
public AvoidStarImportCheck()
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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:
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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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setExcludes
Setter to specify packages where star imports are allowed.- Parameters:
excludesParam
- a list of package names/fully-qualifies class names where star imports are ok.
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setAllowClassImports
public void setAllowClassImports(boolean allow) Setter to control whether to allow starred class imports likeimport java.util.*;
.- Parameters:
allow
- true to allow false to disallow
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setAllowStaticMemberImports
public void setAllowStaticMemberImports(boolean allow) Setter to control whether to allow starred static member imports likeimport static org.junit.Assert.*;
.- Parameters:
allow
- true to allow false to disallow
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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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