com.puppycrawl.tools.checkstyle.checks.imports

Class ImportOrderCheck

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.imports.ImportOrderCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class ImportOrderCheck
extends AbstractCheck

Checks the ordering/grouping of imports. Features are:

• groups imports: ensures that groups of imports come in a specific order (e.g., java. comes first, javax. comes second, then everything else)
• adds a separation between groups : ensures that a blank line sit between each group
• import groups aren't separated internally: ensures that each group aren't separated internally by blank line or comment
• sorts imports inside each group: ensures that imports within each group are in lexicographic order
• sorts according to case: ensures that the comparison between import is case sensitive
• groups static imports: ensures that static imports are at the top (or the bottom) of all the imports, or above (or under) each group, or are treated like non static imports (@see ImportOrderOption

.

 Properties:
 

name	Description	type	default value
option	policy on the relative order between regular imports and static imports	ImportOrderOption	under
groups	list of imports groups (every group identified either by a common prefix string, or by a regular expression enclosed in forward slashes (e.g. /regexp/)	list of strings	empty list
ordered	whether imports within group should be sorted	Boolean	true
separated	whether imports groups should be separated by, at least, one blank line or comment and aren't separated internally	Boolean	false
caseSensitive	whether string comparison should be case sensitive or not. Case sensitive sorting is in ASCII sort order	Boolean	true
sortStaticImportsAlphabetically	whether static imports grouped by top or bottom option are sorted alphabetically or not	Boolean	false
useContainerOrderingForStatic	whether to use container ordering (Eclipse IDE term) for static imports or not	Boolean	false

Example:

To configure the check so that it matches default Eclipse formatter configuration (tested on Kepler, Luna and Mars):

• group of static imports is on the top
• groups of non-static imports: "java" then "javax" packages first, then "org" and then all other imports
• imports will be sorted in the groups
• groups are separated by, at least, one blank line and aren't separated internally

 <module name="ImportOrder">
    <property name="groups" value="/^javax?\./,org"/>
    <property name="ordered" value="true"/>
    <property name="separated" value="true"/>
    <property name="option" value="above"/>
    <property name="sortStaticImportsAlphabetically" value="true"/>
 </module>
 

To configure the check so that it matches default IntelliJ IDEA formatter configuration (tested on v14):

• group of static imports is on the bottom
• groups of non-static imports: all imports except of "javax" and "java", then "javax" and "java"
• imports will be sorted in the groups
• groups are separated by, at least, one blank line and aren't separated internally

Note: "separated" option is disabled because IDEA default has blank line between "java" and static imports, and no blank line between "javax" and "java"

 <module name="ImportOrder">
     <property name="groups" value="*,javax,java"/>
     <property name="ordered" value="true"/>
     <property name="separated" value="false"/>
     <property name="option" value="bottom"/>
     <property name="sortStaticImportsAlphabetically" value="true"/>
 </module>
 

To configure the check so that it matches default NetBeans formatter configuration (tested on v8):

• groups of non-static imports are not defined, all imports will be sorted as a one group
• static imports are not separated, they will be sorted along with other imports

 <module name="ImportOrder">
     <property name="option" value="inflow"/>
 </module>
 

Group descriptions enclosed in slashes are interpreted as regular expressions. If multiple groups match, the one matching a longer substring of the imported name will take precedence, with ties broken first in favor of earlier matches and finally in favor of the first matching group.

There is always a wildcard group to which everything not in a named group belongs. If an import does not match a named group, the group belongs to this wildcard group. The wildcard group position can be specified using the * character.

Check also has on option making it more flexible: sortStaticImportsAlphabetically - sets whether static imports grouped by top or bottom option should be sorted alphabetically or not, default value is false. It is applied to static imports grouped with top or bottom options.
This option is helping in reconciling of this Check and other tools like Eclipse's Organize Imports feature.

To configure the Check allows static imports grouped to the top being sorted alphabetically:

 
 import static java.lang.Math.abs;
 import static org.abego.treelayout.Configuration.AlignmentInLevel; // OK, alphabetical order

 import org.abego.*;

 import java.util.Set;

 public class SomeClass { ... }
 
 

Author:

Bill Schneider, o_sukhodolsky, David DIDIER, Steve McKay, Aleksey Nesterenko, Andrei Selkin

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

AutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field and Description
static String	MSG_ORDERING A key is pointing to the warning message text in "messages.properties" file.
static String	MSG_SEPARATED_IN_GROUP A key is pointing to the warning message text in "messages.properties" file.
static String	MSG_SEPARATION A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
ImportOrderCheck()

Method Summary

Modifier and Type	Method and Description
void	beginTree(DetailAST rootAST) Called before the starting to process 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	setCaseSensitive(boolean caseSensitive) Sets whether string comparison should be case sensitive or not.
void	setGroups(String... packageGroups) Sets the list of package groups and the order they should occur in the file.
void	setOption(String optionStr) Set the option to enforce.
void	setOrdered(boolean ordered) Sets whether or not imports should be ordered within any one group of imports.
void	setSeparated(boolean separated) Sets whether or not groups of imports must be separated from one another by at least one blank line.
void	setSortStaticImportsAlphabetically(boolean sortAlphabetically) Sets whether static imports (when grouped using 'top' and 'bottom' option) are sorted alphabetically or according to the package groupings.
void	setUseContainerOrderingForStatic(boolean useContainerOrdering) Sets whether to use container ordering (Eclipse IDE term) for static imports or not.
void	visitToken(DetailAST ast) Called to process a token.

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

clearMessages, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setClassLoader, 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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MSG_SEPARATION

public static final String MSG_SEPARATION

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

MSG_ORDERING

public static final String MSG_ORDERING

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

MSG_SEPARATED_IN_GROUP

public static final String MSG_SEPARATED_IN_GROUP

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

Constructor Detail

ImportOrderCheck

public ImportOrderCheck()

Method Detail

setOption

public void setOption(String optionStr)

Set the option to enforce.

Parameters:

optionStr - string to decode option from

Throws:

IllegalArgumentException - if unable to decode

setGroups

public void setGroups(String... packageGroups)

Sets the list of package groups and the order they should occur in the file.

Parameters:

packageGroups - a comma-separated list of package names/prefixes.

setOrdered

public void setOrdered(boolean ordered)

Sets whether or not imports should be ordered within any one group of imports.

Parameters:

ordered - whether lexicographic ordering of imports within a group required or not.

setSeparated

public void setSeparated(boolean separated)

Sets whether or not groups of imports must be separated from one another by at least one blank line.

Parameters:

separated - whether groups should be separated by one blank line.

setCaseSensitive

public void setCaseSensitive(boolean caseSensitive)

Sets whether string comparison should be case sensitive or not.

Parameters:

caseSensitive - whether string comparison should be case sensitive.

setSortStaticImportsAlphabetically

public void setSortStaticImportsAlphabetically(boolean sortAlphabetically)

Sets whether static imports (when grouped using 'top' and 'bottom' option) are sorted alphabetically or according to the package groupings.

Parameters:

sortAlphabetically - true or false.

setUseContainerOrderingForStatic

public void setUseContainerOrderingForStatic(boolean useContainerOrdering)

Sets whether to use container ordering (Eclipse IDE term) for static imports or not.

Parameters:

useContainerOrdering - whether to use container ordering for static imports or not.

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 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

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 class AbstractCheck

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 class AbstractCheck

Parameters:

ast - the token to process