Java Fundamental Classes Reference

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The java.text Package
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CharacterIterator

Name

CharacterIterator

Synopsis

Interface Name:

java.text.CharacterIterator

Super-interface:

java.lang.Cloneable

Immediate Sub-interfaces:

None

Implemented By:

java.text.StringCharacterIterator

Availability:

New as of JDK 1.1

Description

The CharacterIterator interface defines methods that support bidirectional movement through a sequence of text. The interface is implemented by classes that maintain a current position in a sequence of characters. The interface provides methods for moving to the first, last, next, and previous characters in the sequence. The BreakIterator classes uses this interface to locate boundaries in textual sequences.

Class Summary

public abstract interface java.text.CharacterIterator
                          extends java.lang.Cloneable {
  // Constants
  public static final char DONE;
  // Methods
  public abstract Object clone();
  public abstract char current();
  public abstract char first();
  public abstract int getBeginIndex();
  public abstract int getEndIndex();
  public abstract int getIndex();
  public abstract char last();
  public abstract char next();
  public abstract char previous();
  public abstract char setIndex(int position);
}

Constants

DONE

public final static char DONE

Description

A constant that indicates that the beginning or end of the text has been reached. It can be returned by next() or previous().

Methods

clone

public abstract Object clone()

Returns

A copy of this CharacterIterator.

Overrides

Object.clone()

Description

This method creates a copy of this CharacterIterator and returns it.

current

public abstract char current()

Returns

The character at the current position of this CharacterIterator or DONE if the current position is not within the text sequence.

Description

This method returns the character at the current position of this CharacterIterator. The current position is returned by getIndex().

first

public abstract char first()

Returns

The first character in this CharacterIterator.

Description

This method returns the character at the first position in this CharacterIterator. The first position is returned by getBeginIndex(). The current position of the iterator is set to this position.

getBeginIndex

public abstract int getBeginIndex()

Returns

The index of the first character in this CharacterIterator.

Description

This method returns the index of the beginning of the text for this CharacterIterator.

getEndIndex

public abstract int getEndIndex()

Returns

The index after the last character in this CharacterIterator.

Description

This method returns the index of the character following the end of the text for this CharacterIterator.

getIndex

public abstract int getIndex()

Returns

The index of the current character in this CharacterIterator.

Description

This method returns the current position, or index, of this CharacterIterator.

last

public abstract char last()

Returns

The last character in this CharacterIterator.

Description

This method returns the character at the ending position of this CharacterIterator. The last position is the value of getEndIndex()-1. The current position of the iterator is set to this position.

next

public abstract char next()

Returns

The next character in this CharacterIterator or DONE if the current position is already at the end of the text.

Description

This method increments the current position of this CharacterIterator by one and returns the character at the new position. If the current position is already at getEndIndex(), the position is not changed, and DONE is returned.

previous

public abstract char previous()

Returns

The previous character in this CharacterIterator or DONE if the current position is already at the beginning of the text.

Description

This method decrements the current position of this CharacterIterator by one and returns the character at the new position. If the current position is already at getBeginIndex(), the position is not changed, and DONE is returned.

setIndex

public abstract char setIndex(int position)

Parameters

position

The new position.

Returns

The character at the specified position in this CharacterIterator.

Throws

IllegalArgumentException

If the given position is not between getBeginIndex() and getEndIndex()-1.

Description

This method sets the current position, or index, of this CharacterIterator to the given position.

See Also

BreakIterator, StringCharacterIterator


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