Package com.puppycrawl.tools.checkstyle.checks.imports

Class PkgImportControl

java.lang.Object

com.puppycrawl.tools.checkstyle.checks.imports.AbstractImportControl

com.puppycrawl.tools.checkstyle.checks.imports.PkgImportControl

class PkgImportControl
extends AbstractImportControl

Represents a tree of import rules for a specific package. Each instance may have zero or more children. A child may be a sub-package, a class, or an allow/disallow rule.

Field Summary

Fields

Modifier and Type	Field	Description
private final List<AbstractImportControl>	children	List of children AbstractImportControl objects.
private static final String	DOT	The package separator: ".".
private static final String	DOT_ESCAPED_REGEX	The regex for the escaped package separator: "\\\\.".
private static final String	DOT_REGEX	The regex for the package separator: "\\.".
private static final Pattern	DOT_REGEX_PATTERN	A pattern matching the package separator: "\.".
private final String	fullPackageName	The full name for the package.
private final Pattern	patternForExactMatch	The regex pattern for exact matches - only not null if regex is true.
private final Pattern	patternForPartialMatch	The regex pattern for partial match (exact and for subpackages) - only not null if regex is true.
private final boolean	regex	If this package represents a regular expression.

Constructor Summary

Constructors

Constructor	Description
PkgImportControl(PkgImportControl parent, String subPackageName, boolean regex, MismatchStrategy strategyOnMismatch)	Construct a sub-package node.
PkgImportControl(String packageName, boolean regex, MismatchStrategy strategyOnMismatch)	Construct a root, package node.

Method Summary

Modifier and Type	Method	Description
void	addChild(AbstractImportControl importControl)	Adds new child import control.
private static Pattern	createPatternForExactMatch(String expression)	Creates a Pattern from expression.
private static Pattern	createPatternForPartialMatch(String expression)	Creates a Pattern from expression that matches exactly and child packages.
private static String	encloseInGroup(String expression)	Enclose expression in a (non-capturing) group.
private static String	ensureSelfContainedRegex(String input, boolean alreadyRegex)	Returns a regex that is suitable for concatenation by 1) either converting a plain string into a regular expression (handling special characters) or 2) by enclosing input in a (non-capturing) group if input already is a regular expression.
AbstractImportControl	locateFinest(String forPkg, String forFileName)	Search down the tree to locate the finest match for a supplied package.
private boolean	matchesAtFront(String pkg)	Matches other package name exactly or partially at front.
private boolean	matchesAtFrontNoRegex(String pkg)	Non-regex case.
protected boolean	matchesExactly(String pkg, String fileName)	Check for equality of this with pkg.
private static String	toRegex(String input)	Converts a normal package name into a regex pattern by escaping all special characters that may occur in a java package name.

Methods inherited from class com.puppycrawl.tools.checkstyle.checks.imports.AbstractImportControl

addImportRule, checkAccess

Methods inherited from class java.lang.Object

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

Field Details

DOT

private static final String DOT

The package separator: ".".

See Also:

• Constant Field Values

DOT_REGEX

private static final String DOT_REGEX

The regex for the package separator: "\\.".

See Also:

• Constant Field Values

DOT_REGEX_PATTERN

private static final Pattern DOT_REGEX_PATTERN

A pattern matching the package separator: "\.".

DOT_ESCAPED_REGEX

private static final String DOT_ESCAPED_REGEX

The regex for the escaped package separator: "\\\\.".

See Also:

• Constant Field Values

children

private final List<AbstractImportControl> children

List of children AbstractImportControl objects.

fullPackageName

private final String fullPackageName

The full name for the package.

patternForPartialMatch

private final Pattern patternForPartialMatch

The regex pattern for partial match (exact and for subpackages) - only not null if regex is true.

patternForExactMatch

private final Pattern patternForExactMatch

The regex pattern for exact matches - only not null if regex is true.

regex

private final boolean regex

If this package represents a regular expression.

Constructor Details

PkgImportControl

PkgImportControl(String packageName,
 boolean regex,
 MismatchStrategy strategyOnMismatch)

Construct a root, package node.

Parameters:

packageName - the name of the package.

regex - flags interpretation of name as regex pattern.

strategyOnMismatch - strategy in a case if matching allow/disallow rule was not found.

PkgImportControl

PkgImportControl(PkgImportControl parent,
 String subPackageName,
 boolean regex,
 MismatchStrategy strategyOnMismatch)

Construct a sub-package node. The concatenation of regular expressions needs special care: see ensureSelfContainedRegex(String, boolean) for more details.

Parameters:

parent - the parent package.

subPackageName - the name of the current sub-package.

regex - flags interpretation of name as regex pattern.

strategyOnMismatch - strategy in a case if matching allow/disallow rule was not found.

Method Details

ensureSelfContainedRegex

private static String ensureSelfContainedRegex(String input,
 boolean alreadyRegex)

Returns a regex that is suitable for concatenation by 1) either converting a plain string into a regular expression (handling special characters) or 2) by enclosing input in a (non-capturing) group if input already is a regular expression.

1) When concatenating a non-regex package component (like "org.google") with a regex component (like "[^.]+") the other component has to be converted into a regex too, see toRegex(String).

2) The grouping is strictly necessary if a) input is a regular expression that b) contains the alteration character ('|') and if c) the pattern is not already enclosed in a group - as you see in this example: parent="com|org", child="common|uncommon" will result in the pattern "(?:org|com)\.(?common|uncommon)" what will match "com.common", "com.uncommon", "org.common", and "org.uncommon". Without the grouping it would be "com|org.common|uncommon" which would match "com", "org.common", and "uncommon", which clearly is undesirable. Adding the group fixes this.

For simplicity the grouping is added to regular expressions unconditionally.

Parameters:

input - the input string.

alreadyRegex - signals if input already is a regular expression.

Returns:

a regex string.

encloseInGroup

private static String encloseInGroup(String expression)

Enclose expression in a (non-capturing) group.

Parameters:

expression - the input regular expression

Returns:

a grouped pattern.

toRegex

private static String toRegex(String input)

Converts a normal package name into a regex pattern by escaping all special characters that may occur in a java package name.

Parameters:

input - the input string.

Returns:

a regex string.

createPatternForPartialMatch

private static Pattern createPatternForPartialMatch(String expression)

Creates a Pattern from expression that matches exactly and child packages.

Parameters:

expression - a self-contained regular expression matching the full package exactly.

Returns:

a Pattern.

createPatternForExactMatch

private static Pattern createPatternForExactMatch(String expression)

Creates a Pattern from expression.

Parameters:

expression - a self-contained regular expression matching the full package exactly.

Returns:

a Pattern.

locateFinest

public AbstractImportControl locateFinest(String forPkg,
 String forFileName)

Description copied from class: AbstractImportControl

Search down the tree to locate the finest match for a supplied package.

Specified by:

locateFinest in class AbstractImportControl

Parameters:

forPkg - the package to search for.

forFileName - the file name to search for.

Returns:

the finest match, or null if no match at all.

addChild

public void addChild(AbstractImportControl importControl)

Adds new child import control.

Parameters:

importControl - child import control

matchesAtFront

private boolean matchesAtFront(String pkg)

Matches other package name exactly or partially at front.

Parameters:

pkg - the package to compare with.

Returns:

if it matches.

matchesAtFrontNoRegex

private boolean matchesAtFrontNoRegex(String pkg)

Non-regex case. Ensure a trailing dot for subpackages, i.e. "com.puppy" will match "com.puppy.crawl" but not "com.puppycrawl.tools".

Parameters:

pkg - the package to compare with.

Returns:

if it matches.

matchesExactly

protected boolean matchesExactly(String pkg,
 String fileName)

Description copied from class: AbstractImportControl

Check for equality of this with pkg.

Specified by:

matchesExactly in class AbstractImportControl

Parameters:

pkg - the package to compare with.

fileName - the file name to compare with.

Returns:

if it matches.