net.sf.saxon.expr.sort
Class AlphanumericCollator

java.lang.Object
  net.sf.saxon.expr.sort.AlphanumericCollator

All Implemented Interfaces:

Serializable, StringCollator

public class AlphanumericCollator
extends Object
implements StringCollator, Serializable

A Comparer that treats strings as an alternating sequence of alpha parts and numeric parts. The alpha parts are compared using a base collation supplied as a parameter; the numeric parts are compared numerically. "Numeric" here means a sequence of consecutive ASCII digits 0-9.

Note: this StringCollator produces an ordering that is not compatible with equals().

See Also:

Serialized Form

Constructor Summary

AlphanumericCollator(StringCollator base)
Create an alphanumeric collation

Method Summary

boolean	comparesEqual(String s1, String s2) Compare two strings for equality.
int	compareStrings(String s1, String s2) Compare two objects.
Object	getCollationKey(String s) Get a collation key for two Strings.

Methods inherited from class java.lang.Object

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

Constructor Detail

AlphanumericCollator

public AlphanumericCollator(StringCollator base)

Create an alphanumeric collation

Parameters:

base - the collation used to compare the alphabetic parts of the string

Method Detail

compareStrings

public int compareStrings(String s1,
                          String s2)

Compare two objects.

Specified by:

compareStrings in interface StringCollator

Parameters:

s1 - the first string

s2 - the second string

Returns:

<0 if a0 if a>b

comparesEqual

public boolean comparesEqual(String s1,
                             String s2)

Compare two strings for equality. This may be more efficient than using compareStrings and testing whether the result is zero, but it must give the same result

Specified by:

comparesEqual in interface StringCollator

Parameters:

s1 - the first string

s2 - the second string

Returns:

true if and only if the strings are considered equal,

getCollationKey

public Object getCollationKey(String s)

Get a collation key for two Strings. The essential property of collation keys is that if two values are equal under the collation, then the collation keys are compare correctly under the equals() method.

Specified by:

getCollationKey in interface StringCollator

Parameters:

s - the string whose collation key is required

Returns:

the collation key