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Java Fundamental Classes Reference

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The java.text Package
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CollationElementIterator

Name

CollationElementIterator

Synopsis

Class Name:

java.text.CollationElementIterator

Superclass:

java.lang.Object

Immediate Subclasses:

None

Interfaces Implemented:

None

Availability:

New as of JDK 1.1

Description

A RuleBasedCollator object creates an instance of the CollationElementIterator class to iterate through the characters of a string and determine their relative collation sequence. A CollationElementIterator object performs callbacks to the RuleBasedCollator that created it to get the information it needs to recognize groups of characters that are treated as single collation characters. For example, a RuleBasedCollator for a Spanish language locale would be set up to treat `ch' as a single letter. A CollationElementIterator object also gets information from its RuleBasedCollator that is used to determine the collation ordering priority for characters.

A collation-ordering priority of a character is a composite integer value that determines how the character is collated. This priority is comprised of:

  • A primary order that distinguishes between different letters. Characters that are considered to be different letters, such as `e' and `f', have different primary orders. Different forms of the same letter, such as `e' and `E', or an accented form of `e', have the same primary order. Primary orders are short values.

  • A secondary order that distinguishes between accented forms of the same letter. An unaccented `e' has a different secondary order than forms of `e' that have different accents. `E' and `e' have the same secondary order, as do upper- and lowercase forms of `e' that have the same accent. Secondary orders are byte values.

  • A tertiary order that distinguishes between case differences. `E' and `e' have different tertiary orders. Tertiary orders are byte values.

The next() method returns the collation-ordering priority of the next logical character. Primary, secondary, and tertiary orders are extracted from an ordering priority with the primaryOrder(), secondaryOrder(), and tertiaryOrder() methods.

Class Summary

public final class java.text.CollationElementIterator
                   extends java.lang.Object {
   // Constants
   public static final int NULLORDER;
 
  // Class Methods
   public static final int primaryOrder(int order);
   public static final short secondaryOrder(int order);
   public static final short tertiaryOrder(int order);
 
  // Instance Methods
   public int next();
   public void reset();
}

Constants

NULLORDER

public final static int NULLORDER

Description

A constant that is returned by next() if the end of the string has been reached.

Class Methods

primaryOrder

public static final int primaryOrder(int order)

Returns

The primary order component of the given order key.

Description

This method extracts the primary order value from the given order key.

secondaryOrder

public static final short secondaryOrder(int order)

Returns

The secondary order component of the given order key.

Description

This method extracts the secondary order value from the given order key.

tertiaryOrder

public static final short tertiaryOrder(int order)

Returns

The tertiary order component of the given order key.

Description

This method extracts the tertiary order value from the given order key.

Instance Methods

next

public int next()

Returns

The order value of the next character in the string.

Description

This method returns the order key for the next character in the string. The returned value can be broken apart using the primaryOrder(), secondaryOrder(), and tertiaryOrder() methods.

reset

public void reset()

Description

This method resets the position of this CollationElementIterator to the beginning of the string.

Inherited Methods

Method Inherited From Method Inherited From

clone()

Object

equals(Object)

Object

finalize()

Object

getClass()

Object

hashCode()

Object

notify()

Object

notifyAll()

Object

toString()

Object

wait()

Object

wait(long)

Object

wait(long, int)

Object

   

See Also

Collator, RuleBasedCollator, String


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