org.springframework.web.util.patterns

Class PathPattern

java.lang.Object

org.springframework.web.util.patterns.PathPattern

All Implemented Interfaces:

java.lang.Comparable<PathPattern>

public class PathPattern
extends java.lang.Object
implements java.lang.Comparable<PathPattern>

Represents a parsed path pattern. Includes a chain of path elements for fast matching and accumulates computed state for quick comparison of patterns.

PathPatterns match URL paths using the following rules:

• ? matches one character
• * matches zero or more characters within a path segment
• ** matches zero or more path segments until the end of the path
• {spring} matches a path segment and captures it as a variable named "spring"
• {spring:[a-z]+} matches the regexp [a-z]+ as a path variable named "spring"
• {*spring} matches zero or more path segments until the end of the path and captures it as a variable named "spring"

Examples

• /pages/t?st.html — matches /pages/test.html but also /pages/tast.html but not /pages/toast.html
• /resources/*.png — matches all .png files in the resources directory
• /resources/** — matches all files underneath the /resources/ path, including /resources/image.png and /resources/css/spring.css
• /resources/{*path} — matches all files underneath the /resources/ path and captures their relative path in a variable named "path"; /resources/image.png will match with "spring" -> "/image.png", and /resources/css/spring.css will match with "spring" -> "/css/spring.css"
• /resources/{filename:\\w+}.dat will match /resources/spring.dat and assign the value "spring" to the filename variable

Since:

5.0

Author:

Andy Clement

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) class	PathPattern.MatchingContext Encapsulates context when attempting a match.

Field Summary

Fields

Modifier and Type	Field and Description
private int	capturedVariableCount How many variables are captured in this pattern
private boolean	caseSensitive Will this match candidates in a case sensitive way? (case sensitivity at parse time)
(package private) boolean	endsWithSeparatorWildcard Does the pattern end with '<separator>*'
private PathElement	head First path element in the parsed chain of path elements for this pattern
private boolean	isCatchAll Does the pattern end with {*...}
private static java.util.Map<java.lang.String,java.lang.String>	NO_VARIABLES_MAP
(package private) int	normalizedLength The normalized length is trying to measure the 'active' part of the pattern.
private java.lang.String	patternString The text of the parsed pattern
private int	score Score is used to quickly compare patterns.
private char	separator The separator used when parsing the pattern

Constructor Summary

Constructors

Constructor and Description
PathPattern(java.lang.String patternText, PathElement head, char separator, boolean caseSensitive)

Method Summary

Modifier and Type	Method and Description
java.lang.String	combine(java.lang.String pattern2string) Combine this pattern with another.
int	compareTo(PathPattern p) Compare this pattern with a supplied pattern.
private java.lang.String	concat(java.lang.String path1, java.lang.String path2) Join two paths together including a separator if necessary.
boolean	equals(java.lang.Object o)
java.lang.String	extractPathWithinPattern(java.lang.String path) Given a full path, determine the pattern-mapped part.
int	getCapturedVariableCount()
PathElement	getHeadSection()
int	getNormalizedLength() The normalized length is trying to measure the 'active' part of the pattern.
java.lang.String	getPatternString()
int	getScore()
char	getSeparator()
int	hashCode()
boolean	isCatchAll()
java.util.Map<java.lang.String,java.lang.String>	matchAndExtract(java.lang.String path)
boolean	matches(java.lang.String path)
boolean	matchStart(java.lang.String path)
java.lang.String	toChainString()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_VARIABLES_MAP

private static final java.util.Map<java.lang.String,java.lang.String> NO_VARIABLES_MAP

head

private PathElement head

First path element in the parsed chain of path elements for this pattern

patternString

private java.lang.String patternString

The text of the parsed pattern

separator

private char separator

The separator used when parsing the pattern

caseSensitive

private boolean caseSensitive

Will this match candidates in a case sensitive way? (case sensitivity at parse time)

capturedVariableCount

private int capturedVariableCount

How many variables are captured in this pattern

normalizedLength

int normalizedLength

The normalized length is trying to measure the 'active' part of the pattern. It is computed by assuming all captured variables have a normalized length of 1. Effectively this means changing your variable name lengths isn't going to change the length of the active part of the pattern. Useful when comparing two patterns.

endsWithSeparatorWildcard

boolean endsWithSeparatorWildcard

Does the pattern end with '<separator>*'

score

private int score

Score is used to quickly compare patterns. Different pattern components are given different weights. A 'lower score' is more specific. Current weights:

• Captured variables are worth 1
• Wildcard is worth 100

isCatchAll

private boolean isCatchAll

Does the pattern end with {*...}

Constructor Detail

PathPattern

public PathPattern(java.lang.String patternText,
                   PathElement head,
                   char separator,
                   boolean caseSensitive)

Method Detail

matches

public boolean matches(java.lang.String path)

Parameters:

path - the candidate path to attempt to match against this pattern

Returns:

true if the path matches this pattern

matchStart

public boolean matchStart(java.lang.String path)

Parameters:

path - the path to check against the pattern

Returns:

true if the pattern matches as much of the path as is supplied

matchAndExtract

public java.util.Map<java.lang.String,java.lang.String> matchAndExtract(java.lang.String path)

Parameters:

path - a path to match against this pattern

Returns:

a map of extracted variables - an empty map if no variables extracted.

getPatternString

public java.lang.String getPatternString()

Returns:

the original pattern string that was parsed to create this PathPattern

getHeadSection

public PathElement getHeadSection()

extractPathWithinPattern

public java.lang.String extractPathWithinPattern(java.lang.String path)

Given 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'

Note: Assumes that matches(java.lang.String) returns true for 'pattern' and 'path', but does not enforce this. As per the contract on PathMatcher, this method will trim leading/trailing separators. It will also remove duplicate separators in the returned path.

Parameters:

path - a path that matches this pattern

Returns:

the subset of the path that is matched by pattern or "" if none of it is matched by pattern elements

compareTo

public int compareTo(PathPattern p)

Compare this pattern with a supplied pattern. Return -1,0,+1 if this pattern is more specific, the same or less specific than the supplied pattern. The aim is to sort more specific patterns first.

Specified by:

compareTo in interface java.lang.Comparable<PathPattern>

getScore

public int getScore()

isCatchAll

public boolean isCatchAll()

getNormalizedLength

public int getNormalizedLength()

The normalized length is trying to measure the 'active' part of the pattern. It is computed by assuming all capture variables have a normalized length of 1. Effectively this means changing your variable name lengths isn't going to change the length of the active part of the pattern. Useful when comparing two patterns.

Returns:

the normalized length of the pattern

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toChainString

public java.lang.String toChainString()

getSeparator

public char getSeparator()

getCapturedVariableCount

public int getCapturedVariableCount()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

combine

public java.lang.String combine(java.lang.String pattern2string)

Combine this pattern with another. Currently does not produce a new PathPattern, just produces a new string.

concat

private java.lang.String concat(java.lang.String path1,
                                java.lang.String path2)

Join two paths together including a separator if necessary. Extraneous separators are removed (if the first path ends with one and the second path starts with one).

Parameters:

path1 - First path

path2 - Second path

Returns:

joined path that may include separator if necessary