java.text
Interface CharacterIterator

All Superinterfaces:
Cloneable
All Known Subinterfaces:
AttributedCharacterIterator
All Known Implementing Classes:
Segment, StringCharacterIterator

public interface CharacterIterator
extends Cloneable

This interface defines a mechanism for iterating over a range of characters. For a given range of text, a beginning and ending index, as well as a current index are defined. These values can be queried by the methods in this interface. Additionally, various methods allow the index to be set.


Field Summary
static char DONE
          This is a special constant value that is returned when the beginning or end of the character range has been reached.
 
Method Summary
 Object clone()
          This method creates a copy of this CharacterIterator.
 char current()
          This method returns the character at the current index position
 char first()
          This method sets the index value to the beginning of the range and returns the character there.
 int getBeginIndex()
          This method returns the character position of the first character in the range.
 int getEndIndex()
          This method returns the character position of the end of the text range.
 int getIndex()
          This method returns the current value of the index.
 char last()
          This method sets the index value to getEndIndex() - 1 and returns the character there.
 char next()
          This method increments the current index and then returns the character at the new index value.
 char previous()
          This method decrements the current index and then returns the character at the new index value.
 char setIndex(int index)
          This method sets the value of the index to the specified value, then returns the character at that position.
 

Field Detail

DONE

static final char DONE
This is a special constant value that is returned when the beginning or end of the character range has been reached.

See Also:
Constant Field Values
Method Detail

current

char current()
This method returns the character at the current index position

Returns:
The character at the current index position.

next

char next()
This method increments the current index and then returns the character at the new index value. If the index is already at getEndIndex() - 1, it will not be incremented.

Returns:
The character at the position of the incremented index value, or DONE if the index has reached getEndIndex() - 1

previous

char previous()
This method decrements the current index and then returns the character at the new index value. If the index value is already at the beginning index, it will not be decremented.

Returns:
The character at the position of the decremented index value, or DONE if index was already equal to the beginning index value.

first

char first()
This method sets the index value to the beginning of the range and returns the character there.

Returns:
The character at the beginning of the range, or DONE if the range is empty.

last

char last()
This method sets the index value to getEndIndex() - 1 and returns the character there. If the range is empty, then the index value will be set equal to the beginning index.

Returns:
The character at the end of the range, or DONE if the range is empty.

getIndex

int getIndex()
This method returns the current value of the index.

Returns:
The current index value

setIndex

char setIndex(int index)
              throws IllegalArgumentException
This method sets the value of the index to the specified value, then returns the character at that position.

Parameters:
index - The new index value.
Returns:
The character at the new index value or DONE if the index value is equal to getEndIndex().
Throws:
IllegalArgumentException

getBeginIndex

int getBeginIndex()
This method returns the character position of the first character in the range.

Returns:
The index of the first character in the range.

getEndIndex

int getEndIndex()
This method returns the character position of the end of the text range. This will actually be the index of the first character following the end of the range. In the event the text range is empty, this will be equal to the first character in the range.

Returns:
The index of the end of the range.

clone

Object clone()
This method creates a copy of this CharacterIterator.

Returns:
A copy of this CharacterIterator.