org.apache.struts.util
Class WildcardHelper

java.lang.Object
  org.apache.struts.util.WildcardHelper

public class WildcardHelper
extends Object

This class is an utility class that perform wilcard-patterns matching and isolation taken from Apache Cocoon.

Since:

Struts 1.2

Version:

$Rev: 471754 $ $Date: 2005-05-07 12:11:38 -0400 (Sat, 07 May 2005) $

Field Summary

protected static int	MATCH_BEGIN The int representing begin in the pattern int [].
protected static int	MATCH_END The int value that terminates the pattern int [].
protected static int	MATCH_FILE The int representing '*' in the pattern int [].
protected static int	MATCH_PATH The int representing '**' in the pattern int [].
protected static int	MATCH_THEEND The int representing end in pattern int [].

Constructor Summary

WildcardHelper()

Method Summary

int[]	compilePattern(String data) Translate the given String into a int [] representing the pattern matchable by this class.
protected int	indexOfArray(int[] r, int rpos, int rend, char[] d, int dpos) Get the offset of a part of an int array within a char array.
protected int	lastIndexOfArray(int[] r, int rpos, int rend, char[] d, int dpos) Get the offset of a last occurance of an int array within a char array.
boolean	match(Map map, String data, int[] expr) Match a pattern agains a string and isolates wildcard replacement into a Stack.
protected boolean	matchArray(int[] r, int rpos, int rend, char[] d, int dpos) Matches elements of array r from rpos to rend with array d, starting from dpos.

Methods inherited from class java.lang.Object

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

Field Detail

MATCH_FILE

protected static final int MATCH_FILE

The int representing '*' in the pattern int [].

See Also:

Constant Field Values

MATCH_PATH

protected static final int MATCH_PATH

The int representing '**' in the pattern int [].

See Also:

Constant Field Values

MATCH_BEGIN

protected static final int MATCH_BEGIN

The int representing begin in the pattern int [].

See Also:

Constant Field Values

MATCH_THEEND

protected static final int MATCH_THEEND

The int representing end in pattern int [].

See Also:

Constant Field Values

MATCH_END

protected static final int MATCH_END

The int value that terminates the pattern int [].

See Also:

Constant Field Values

Constructor Detail

WildcardHelper

public WildcardHelper()

Method Detail

compilePattern

public int[] compilePattern(String data)

Translate the given String into a int [] representing the pattern matchable by this class.
This function translates a String into an int array converting the special '*' and '\' characters.
Here is how the conversion algorithm works:

• The '*' character is converted to MATCH_FILE, meaning that zero or more characters (excluding the path separator '/') are to be matched.
• The '**' sequence is converted to MATCH_PATH, meaning that zero or more characters (including the path separator '/') are to be matched.
• The '\' character is used as an escape sequence ('\*' is translated in '*', not in MATCH_FILE). If an exact '\' character is to be matched the source string must contain a '\\'. sequence.

When more than two '*' characters, not separated by another character, are found their value is considered as '**' (MATCH_PATH).
The array is always terminated by a special value (MATCH_END).
All MATCH* values are less than zero, while normal characters are equal or greater.

Parameters:

data - The string to translate.

Returns:

The encoded string as an int array, terminated by the MATCH_END value (don't consider the array length).

Throws:

NullPointerException - If data is null.

match

public boolean match(Map map,
                     String data,
                     int[] expr)

Match a pattern agains a string and isolates wildcard replacement into a Stack.

Parameters:

map - The map to store matched values

data - The string to match

expr - The compiled wildcard expression

Returns:

True if a match

Throws:

NullPointerException - If any parameters are null

indexOfArray

protected int indexOfArray(int[] r,
                           int rpos,
                           int rend,
                           char[] d,
                           int dpos)

Get the offset of a part of an int array within a char array.
This method return the index in d of the first occurrence after dpos of that part of array specified by r, starting at rpos and terminating at rend.

Parameters:

r - The array containing the data that need to be matched in d.

rpos - The index of the first character in r to look for.

rend - The index of the last character in r to look for plus 1.

d - The array of char that should contain a part of r.

dpos - The starting offset in d for the matching.

Returns:

The offset in d of the part of r matched in d or -1 if that was not found.

lastIndexOfArray

protected int lastIndexOfArray(int[] r,
                               int rpos,
                               int rend,
                               char[] d,
                               int dpos)

Get the offset of a last occurance of an int array within a char array.
This method return the index in d of the last occurrence after dpos of that part of array specified by r, starting at rpos and terminating at rend.

Parameters:

r - The array containing the data that need to be matched in d.

rpos - The index of the first character in r to look for.

rend - The index of the last character in r to look for plus 1.

d - The array of char that should contain a part of r.

dpos - The starting offset in d for the matching.

Returns:

The offset in d of the last part of r matched in d or -1 if that was not found.

matchArray

protected boolean matchArray(int[] r,
                             int rpos,
                             int rend,
                             char[] d,
                             int dpos)

Matches elements of array r from rpos to rend with array d, starting from dpos.
This method return true if elements of array r from rpos to rend equals elements of array d starting from dpos to dpos+(rend-rpos).

Parameters:

r - The array containing the data that need to be matched in d.

rpos - The index of the first character in r to look for.

rend - The index of the last character in r to look for.

d - The array of char that should start from a part of r.

dpos - The starting offset in d for the matching.

Returns:

true if array d starts from portion of array r.