org.springframework.util

Class AntPathMatcher

java.lang.Object

org.springframework.util.AntPathMatcher

All Implemented Interfaces:

PathMatcher

public class AntPathMatcher
extends Object
implements PathMatcher

PathMatcher implementation for Ant-style path patterns. Examples are provided below.

Part of this mapping code has been kindly borrowed from Apache Ant.

The mapping matches URLs using the following rules:

• ? matches one character
• * matches zero or more characters
• ** matches zero or more 'directories' in a path

Some examples:

• com/t?st.jsp - matches com/test.jsp but also com/tast.jsp or com/txst.jsp
• com/*.jsp - matches all .jsp files in the com directory
• com/**/test.jsp - matches all test.jsp files underneath the com path
• org/springframework/**/*.jsp - matches all .jsp files underneath the org/springframework path
• org/**/servlet/bla.jsp - matches org/springframework/servlet/bla.jsp but also org/springframework/testing/servlet/bla.jsp and org/servlet/bla.jsp

Since:

16.07.2003

Author:

Alef Arendsen, Juergen Hoeller, Rob Harrop, Arjen Poutsma, Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AntPathMatcher.AntPathStringMatcher Tests whether or not a string matches against a pattern via a Pattern.
protected static class	AntPathMatcher.AntPatternComparator The default Comparator implementation returned by getPatternComparator(String).

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_PATH_SEPARATOR Default path separator: "/"

Constructor Summary

Constructors

Constructor and Description
AntPathMatcher() Create a new instance with the DEFAULT_PATH_SEPARATOR.
AntPathMatcher(String pathSeparator) A convenience alternative constructor to use with a custom path separator.

Method Summary

Modifier and Type	Method and Description
String	combine(String pattern1, String pattern2) Combines two patterns into a new pattern that is returned.
protected boolean	doMatch(String pattern, String path, boolean fullMatch, Map<String,String> uriTemplateVariables) Actually match the given path against the given pattern.
String	extractPathWithinPattern(String pattern, String path) Given a pattern and a full path, determine the pattern-mapped part.
Map<String,String>	extractUriTemplateVariables(String pattern, String path) Given a pattern and a full path, extract the URI template variables.
Comparator<String>	getPatternComparator(String path) Given a full path, returns a Comparator suitable for sorting patterns in order of explicitness.
protected AntPathMatcher.AntPathStringMatcher	getStringMatcher(String pattern) Build or retrieve an AntPathMatcher.AntPathStringMatcher for the given pattern.
boolean	isPattern(String path) Does the given path represent a pattern that can be matched by an implementation of this interface?
boolean	match(String pattern, String path) Match the given path against the given pattern, according to this PathMatcher's matching strategy.
boolean	matchStart(String pattern, String path) Match the given path against the corresponding part of the given pattern, according to this PathMatcher's matching strategy.
void	setCachePatterns(boolean cachePatterns) Specify whether to cache parsed pattern metadata for patterns passed into this matcher's match(java.lang.String, java.lang.String) method.
void	setPathSeparator(String pathSeparator) Set the path separator to use for pattern parsing.
void	setTrimTokens(boolean trimTokens) Specify whether to trim tokenized paths and patterns.
protected String[]	tokenizePath(String path) Tokenize the given path String into parts, based on this matcher's settings.
protected String[]	tokenizePattern(String pattern) Tokenize the given path pattern into parts, based on this matcher's settings.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PATH_SEPARATOR

public static final String DEFAULT_PATH_SEPARATOR

Default path separator: "/"

See Also:

Constant Field Values

Constructor Detail

AntPathMatcher

public AntPathMatcher()

Create a new instance with the DEFAULT_PATH_SEPARATOR.

AntPathMatcher

public AntPathMatcher(String pathSeparator)

A convenience alternative constructor to use with a custom path separator.

Parameters:

pathSeparator - the path separator to use, must not be null.

Since:

4.1

Method Detail

setPathSeparator

public void setPathSeparator(String pathSeparator)

Set the path separator to use for pattern parsing. Default is "/", as in Ant.

setTrimTokens

public void setTrimTokens(boolean trimTokens)

Specify whether to trim tokenized paths and patterns. Default is true.

setCachePatterns

public void setCachePatterns(boolean cachePatterns)

Specify whether to cache parsed pattern metadata for patterns passed into this matcher's match(java.lang.String, java.lang.String) method. A value of true activates an unlimited pattern cache; a value of false turns the pattern cache off completely.

Default is for the cache to be on, but with the variant to automatically turn it off when encountering too many patterns to cache at runtime (the threshold is 65536), assuming that arbitrary permutations of patterns are coming in, with little chance for encountering a reoccurring pattern.

See Also:

getStringMatcher(String)

isPattern

public boolean isPattern(String path)

Description copied from interface: PathMatcher

Does the given path represent a pattern that can be matched by an implementation of this interface?

If the return value is false, then the PathMatcher.match(java.lang.String, java.lang.String) method does not have to be used because direct equality comparisons on the static path Strings will lead to the same result.

Specified by:

isPattern in interface PathMatcher

Parameters:

path - the path String to check

Returns:

true if the given path represents a pattern

match

public boolean match(String pattern,
                     String path)

Description copied from interface: PathMatcher

Match the given path against the given pattern, according to this PathMatcher's matching strategy.

Specified by:

match in interface PathMatcher

Parameters:

pattern - the pattern to match against

path - the path String to test

Returns:

true if the supplied path matched, false if it didn't

matchStart

public boolean matchStart(String pattern,
                          String path)

Description copied from interface: PathMatcher

Match the given path against the corresponding part of the given pattern, according to this PathMatcher's matching strategy.

Determines whether the pattern at least matches as far as the given base path goes, assuming that a full path may then match as well.

Specified by:

matchStart in interface PathMatcher

Parameters:

pattern - the pattern to match against

path - the path String to test

Returns:

true if the supplied path matched, false if it didn't

doMatch

protected boolean doMatch(String pattern,
                          String path,
                          boolean fullMatch,
                          Map<String,String> uriTemplateVariables)

Actually match the given path against the given pattern.

Parameters:

pattern - the pattern to match against

path - the path String to test

fullMatch - whether a full pattern match is required (else a pattern match as far as the given base path goes is sufficient)

Returns:

true if the supplied path matched, false if it didn't

tokenizePattern

protected String[] tokenizePattern(String pattern)

Tokenize the given path pattern into parts, based on this matcher's settings.

Performs caching based on setCachePatterns(boolean), delegating to tokenizePath(String) for the actual tokenization algorithm.

Parameters:

pattern - the pattern to tokenize

Returns:

the tokenized pattern parts

tokenizePath

protected String[] tokenizePath(String path)

Tokenize the given path String into parts, based on this matcher's settings.

Parameters:

path - the path to tokenize

Returns:

the tokenized path parts

getStringMatcher

protected AntPathMatcher.AntPathStringMatcher getStringMatcher(String pattern)

Build or retrieve an AntPathMatcher.AntPathStringMatcher for the given pattern.

The default implementation checks this AntPathMatcher's internal cache (see setCachePatterns(boolean)), creating a new AntPathStringMatcher instance if no cached copy is found. When encountering too many patterns to cache at runtime (the threshold is 65536), it turns the default cache off, assuming that arbitrary permutations of patterns are coming in, with little chance for encountering a reoccurring pattern.

This method may get overridden to implement a custom cache strategy.

Parameters:

pattern - the pattern to match against (never null)

Returns:

a corresponding AntPathStringMatcher (never null)

See Also:

setCachePatterns(boolean)

extractPathWithinPattern

public String extractPathWithinPattern(String pattern,
                                       String path)

Given a pattern and a full path, determine the pattern-mapped part.

For example:

• '/docs/cvs/commit.html' and '/docs/cvs/commit.html -> ''
• '/docs/*' and '/docs/cvs/commit -> 'cvs/commit'
• '/docs/cvs/*.html' and '/docs/cvs/commit.html -> 'commit.html'
• '/docs/**' and '/docs/cvs/commit -> 'cvs/commit'
• '/docs/**\/*.html' and '/docs/cvs/commit.html -> 'cvs/commit.html'
• '/*.html' and '/docs/cvs/commit.html -> 'docs/cvs/commit.html'
• '*.html' and '/docs/cvs/commit.html -> '/docs/cvs/commit.html'
• '*' and '/docs/cvs/commit.html -> '/docs/cvs/commit.html'

Assumes that match(java.lang.String, java.lang.String) returns true for 'pattern' and 'path', but does not enforce this.

Specified by:

extractPathWithinPattern in interface PathMatcher

Parameters:

pattern - the path pattern

path - the full path to introspect

Returns:

the pattern-mapped part of the given path (never null)

extractUriTemplateVariables

public Map<String,String> extractUriTemplateVariables(String pattern,
                                                      String path)

Description copied from interface: PathMatcher

Given a pattern and a full path, extract the URI template variables. URI template variables are expressed through curly brackets ('{' and '}').

For example: For pattern "/hotels/{hotel}" and path "/hotels/1", this method will return a map containing "hotel"->"1".

Specified by:

extractUriTemplateVariables in interface PathMatcher

Parameters:

pattern - the path pattern, possibly containing URI templates

path - the full path to extract template variables from

Returns:

a map, containing variable names as keys; variables values as values

combine

public String combine(String pattern1,
                      String pattern2)

Combines two patterns into a new pattern that is returned.

This implementation simply concatenates the two patterns, unless the first pattern contains a file extension match (such as *.html. In that case, the second pattern should be included in the first, or an IllegalArgumentException is thrown.

For example:

Pattern 1	Pattern 2	Result
/hotels	null	/hotels
null	/hotels	/hotels
/hotels	/bookings	/hotels/bookings
/hotels	bookings	/hotels/bookings
/hotels/*	/bookings	/hotels/bookings
/hotels/**	/bookings	/hotels/**/bookings
/hotels	{hotel}	/hotels/{hotel}
/hotels/*	{hotel}	/hotels/{hotel}
/hotels/**	{hotel}	/hotels/**/{hotel}
/*.html	/hotels.html	/hotels.html
/*.html	/hotels	/hotels.html
/*.html	/*.txt	IllegalArgumentException

Specified by:

combine in interface PathMatcher

Parameters:

pattern1 - the first pattern

pattern2 - the second pattern

Returns:

the combination of the two patterns

Throws:

IllegalArgumentException - when the two patterns cannot be combined

getPatternComparator

public Comparator<String> getPatternComparator(String path)

Given a full path, returns a Comparator suitable for sorting patterns in order of explicitness.

The returned Comparator will sort a list so that more specific patterns (without uri templates or wild cards) come before generic patterns. So given a list with the following patterns:

1. /hotels/new
2. /hotels/{hotel}
3. /hotels/*

the returned comparator will sort this list so that the order will be as indicated.

The full path given as parameter is used to test for exact matches. So when the given path is /hotels/2, the pattern /hotels/2 will be sorted before /hotels/1.

Specified by:

getPatternComparator in interface PathMatcher

Parameters:

path - the full path to use for comparison

Returns:

a comparator capable of sorting patterns in order of explicitness