Android - An Open Handset Alliance Project

java.nio
public abstract class

java.nio.CharBuffer

java.lang.Object
	java.nio.Buffer
		java.nio.CharBuffer	Appendable CharSequence Comparable Readable

A buffer of chars.

A char buffer can be created in either of the following ways:

Allocate a new char array and create a buffer based on it;
Wrap an existing char array to create a new buffer;
Wrap an existing char sequence to create a new buffer;
Use ByteBuffer.asCharBuffer to create a char buffer based on a byte buffer.

Summary

Public Methods

		static	CharBuffer	allocate(int capacity)
				Creates a char buffer based on a new allocated char array.
			CharBuffer	append(char c)
				Append the given character.
			CharBuffer	append(CharSequence csq)
				Append the given `CharSequence`.
			CharBuffer	append(CharSequence csq, int start, int end)
				Append part of the given `CharSequence`.
	final		char[]	array()
				Returns the char array which this buffer is based on, if there's one.
	final		int	arrayOffset()
				Returns the offset of the char array which this buffer is based on, if there's one.
abstract			CharBuffer	asReadOnlyBuffer()
				Returns a readonly buffer that shares content with this buffer.
	final		char	charAt(int index)
				Returns the character located at the specified index in the buffer.
abstract			CharBuffer	compact()
				Compacts this char buffer.
			int	compareTo(CharBuffer otherBuffer)
				Compare the remaining `char`s of this buffer to another char buffer's remaining `char`s.
abstract			CharBuffer	duplicate()
				Returns a duplicated buffer that shares content with this buffer.
			boolean	equals(Object other)
				Tests whether this char buffer equals to another object.
abstract			char	get()
				Returns the char at the current position and increase the position by 1.
			CharBuffer	get(char[] dest)
				Reads `char`s from the current position into the specified char array and increase the position by the number of `char`s read.
abstract			char	get(int index)
				Returns a char at the specified index, and the position is not changed.
			CharBuffer	get(char[] dest, int off, int len)
				Reads `char`s from the current position into the specified char array, starting from the specified offset, and increase the position by the number of `char`s read.
	final		boolean	hasArray()
				Returns whether this buffer is based on a char array and is read/write.
			int	hashCode()
				Hash code is calculated from the remaining `char`s.
abstract			boolean	isDirect()
				Returns true if this buffer is direct.
	final		int	length()
				Returns the number of remaining `char`s.
abstract			ByteOrder	order()
				Returns the byte order used by this buffer when converting `char`s from/to `byte`s.
			CharBuffer	put(char[] src, int off, int len)
				Writes `char`s in the given char array, starting from the specified offset, to the current position and increase the position by the number of `char`s written.
abstract			CharBuffer	put(int index, char c)
				Write a char to the specified index of this buffer and the position is not changed.
abstract			CharBuffer	put(char c)
				Writes the given char to the current position and increase the position by 1.
			CharBuffer	put(CharBuffer src)
				Writes all the remaining `char`s of the `src` char buffer to this buffer's current position, and increase both buffers' position by the number of `char`s copied.
	final		CharBuffer	put(char[] src)
				Writes `char`s in the given char array to the current position and increase the position by the number of `char`s written.
	final		CharBuffer	put(String str)
				Write all `char`s of the give string to the current position of this buffer, and increase the position by the length of string.
			CharBuffer	put(String str, int start, int end)
				Write `char`s of the given string to the current position of this buffer, and increase the position by the number of `char`s written.
			int	read(CharBuffer target)
				Reads the characters into the given `CharBuffer`.
abstract			CharBuffer	slice()
				Returns a sliced buffer that shares content with this buffer.
abstract			CharSequence	subSequence(int start, int end)
				Returns a new char buffer represents a sub-sequence of this buffer's current remaining content.
			String	toString()
				Returns a string represents the current remaining `char`s of this buffer.
		static	CharBuffer	wrap(char[] array, int start, int len)
				Creates new a char buffer by wrapping the given char array.
		static	CharBuffer	wrap(CharSequence chseq)
				Creates a new char buffer by wrapping the given char sequence.
		static	CharBuffer	wrap(char[] array)
				Creates a new char buffer by wrapping the given char array.
		static	CharBuffer	wrap(CharSequence chseq, int start, int end)
				Creates a new char buffer by wrapping the given char sequence.

Methods inherited from class java.nio.Buffer

capacity, clear, flip, hasRemaining, isReadOnly, limit, limit, mark, position, position, remaining, reset, rewind

	final	int	capacity()
			Returns the capacity of this buffer.
	final	Buffer	clear()
			Clears this buffer.
	final	Buffer	flip()
			Flips this buffer.
	final	boolean	hasRemaining()
			Returns true if there are remaining element(s) in this buffer.
abstract		boolean	isReadOnly()
			Returns whether this buffer is readonly or not.
	final	int	limit()
			Returns the limit of this buffer.
	final	Buffer	limit(int newLimit)
			Sets the limit of this buffer.
	final	Buffer	mark()
			Mark the current position, so that the position may return to this point later by calling `reset()`.
	final	int	position()
			Returns the position of this buffer.
	final	Buffer	position(int newPosition)
			Sets the position of this buffer.
	final	int	remaining()
			Returns the number of remaining elements in this buffer.
	final	Buffer	reset()
			Reset the position of this buffer to the `mark`.
	final	Buffer	rewind()
			Rewinds this buffer.

Methods inherited from class java.lang.Object

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

	Object	clone()
		Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
	boolean	equals(Object o)
		Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
	void	finalize()
		Called by the virtual machine when there are no longer any (non-weak) references to the receiver.
final	Class	getClass()
		Answers the unique instance of java.lang.Class which represents the class of the receiver.
	int	hashCode()
		Answers an integer hash code for the receiver.
final	void	notify()
		Causes one thread which is `wait` ing on the receiver to be made ready to run.
final	void	notifyAll()
		Causes all threads which are `wait` ing on the receiver to be made ready to run.
	String	toString()
		Answers a string containing a concise, human-readable description of the receiver.
final	void	wait(long time, int frac)
		Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by `notify` or `notifyAll`) or the expiration of the timeout.
final	void	wait(long time)
		Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by `notify` or `notifyAll`) or the expiration of the timeout.
final	void	wait()
		Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by `notify` or `notifyAll`).

Details

Public Methods

public static CharBuffer allocate(int capacity)

Creates a char buffer based on a new allocated char array.

Parameters

capacity	The capacity of the new buffer

Returns

The created char buffer

Throws

IllegalArgumentException	If `capacity` is less than zero

public CharBuffer append(char c)

Append the given character.

public CharBuffer append(CharSequence csq)

Append the given CharSequence.

The behaviour of this method depends on the implementation class of Appendable.

If the give CharSequence is null, the sequence is treated as String "null".

public CharBuffer append(CharSequence csq, int start, int end)

Append part of the given CharSequence.

If the given CharSequence is not null, this method behaves same as the following statement:

    out.append(csq.subSequence(start, end))

If the give CharSequence is null, the sequence is treated as String "null".

public final char[] array()

Returns the char array which this buffer is based on, if there's one.

Returns

The char array which this buffer is based on

Throws

ReadOnlyBufferException	If this buffer is based on an array, but it is readonly
UnsupportedOperationException	If this buffer is not based on an array

public final int arrayOffset()

Returns the offset of the char array which this buffer is based on, if there's one.

The offset is the index of the array corresponds to the zero position of the buffer.

Returns

The offset of the char array which this buffer is based on

Throws

ReadOnlyBufferException	If this buffer is based on an array, but it is readonly
UnsupportedOperationException	If this buffer is not based on an array

public abstract CharBuffer asReadOnlyBuffer()

Returns a readonly buffer that shares content with this buffer.

The returned buffer is guaranteed to be a new instance, even this buffer is readonly itself. The new buffer's position, limit, capacity and mark are the same as this buffer.

The new buffer shares content with this buffer, which means this buffer's change of content will be visible to the new buffer. The two buffer's position, limit and mark are independent.

Returns

A readonly version of this buffer.

public final char charAt(int index)

Returns the character located at the specified index in the buffer. The index value is referenced from the current buffer position.

Parameters

index	The index referenced from the current buffer position. It must not be less than zero but less than the value obtained from a call to `remaining()`

Returns

the character located at the specified index (referenced from the current position) in the buffer.

Throws

IndexOutOfBoundsException	If the index is invalid

public abstract CharBuffer compact()

Compacts this char buffer.

The remaining chars will be moved to the head of the buffer, staring from position zero. Then the position is set to remaining(); the limit is set to capacity; the mark is cleared.

Returns

This buffer

Throws

ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public int compareTo(CharBuffer otherBuffer)

Compare the remaining chars of this buffer to another char buffer's remaining chars.

Parameters

otherBuffer	Another char buffer

Returns

a negative value if this is less than other; 0 if this equals to other; a positive value if this is greater than other

Throws

ClassCastException	If `other` is not a char buffer

public abstract CharBuffer duplicate()

Returns a duplicated buffer that shares content with this buffer.

The duplicated buffer's position, limit, capacity and mark are the same as this buffer. The duplicated buffer's readonly property and byte order are same as this buffer too.

The new buffer shares content with this buffer, which means either buffer's change of content will be visible to the other. The two buffer's position, limit and mark are independent.

Returns

A duplicated buffer that shares content with this buffer.

public boolean equals(Object other)

Tests whether this char buffer equals to another object.

If other is not a char buffer, then false is returned.

Two char buffers are equals if, and only if, their remaining chars are exactly the same. Position, limit, capacity and mark are not considered.

Parameters

other	the object to be compared against

Returns

Whether this char buffer equals to another object.

public abstract char get()

Returns the char at the current position and increase the position by 1.

Returns

The char at the current position.

Throws

BufferUnderflowException	If the position is equal or greater than limit

public CharBuffer get(char[] dest)

Reads chars from the current position into the specified char array and increase the position by the number of chars read.

Calling this method has the same effect as get(dest, 0, dest.length).

Parameters

dest	The destination char array

Returns

This buffer

Throws

BufferUnderflowException	if `dest.length` is greater than `remaining()`

public abstract char get(int index)

Returns a char at the specified index, and the position is not changed.

Parameters

index	The index, must be no less than zero and less than limit

Returns

A char at the specified index.

Throws

IndexOutOfBoundsException	If index is invalid

public CharBuffer get(char[] dest, int off, int len)

Reads chars from the current position into the specified char array, starting from the specified offset, and increase the position by the number of chars read.

Parameters

dest	The target char array
off	The offset of the char array, must be no less than zero and no greater than `dest.length`
len	The number of `char`s to read, must be no less than zero and no greater than `dest.length - off`

Returns

This buffer

Throws

IndexOutOfBoundsException	If either `off` or `len` is invalid
BufferUnderflowException	If `len` is greater than `remaining()`

public final boolean hasArray()

Returns whether this buffer is based on a char array and is read/write.

If this buffer is readonly, then false is returned.

Returns

Whether this buffer is based on a char array and is read/write.

public int hashCode()

Hash code is calculated from the remaining chars.

Position, limit, capacity and mark don't affect the hash code.

Returns

The hash code calculated from the remaining chars.

public abstract boolean isDirect()

Returns true if this buffer is direct.

A direct buffer will try its best to take advantage of native memory APIs and it may not stay in java heap, thus not affected by GC.

A char buffer is direct, if it is based on a byte buffer and the byte buffer is direct.

Returns

True if this buffer is direct.

public final int length()

Returns the number of remaining chars.

Returns

The number of remaining chars.

public abstract ByteOrder order()

Returns the byte order used by this buffer when converting chars from/to bytes.

If this buffer is not based on a byte buffer, then always return the platform's native byte order.

Returns

The byte order used by this buffer when converting chars from/to bytes.

public CharBuffer put(char[] src, int off, int len)

Writes chars in the given char array, starting from the specified offset, to the current position and increase the position by the number of chars written.

Parameters

src	The source char array
off	The offset of char array, must be no less than zero and no greater than `src.length`
len	The number of `char`s to write, must be no less than zero and no greater than `src.length - off`

Returns

This buffer

Throws

BufferOverflowException	If `remaining()` is less than `len`
IndexOutOfBoundsException	If either `off` or `len` is invalid
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public abstract CharBuffer put(int index, char c)

Write a char to the specified index of this buffer and the position is not changed.

Parameters

index	The index, must be no less than zero and less than the limit
c	The char to write

Returns

This buffer

Throws

IndexOutOfBoundsException	If index is invalid
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public abstract CharBuffer put(char c)

Writes the given char to the current position and increase the position by 1.

Parameters

c	The char to write

Returns

This buffer

Throws

BufferOverflowException	If position is equal or greater than limit
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public CharBuffer put(CharBuffer src)

Writes all the remaining chars of the src char buffer to this buffer's current position, and increase both buffers' position by the number of chars copied.

Parameters

src	The source char buffer

Returns

This buffer

Throws

BufferOverflowException	If `src.remaining()` is greater than this buffer's `remaining()`
IllegalArgumentException	If `src` is this buffer
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public final CharBuffer put(char[] src)

Writes chars in the given char array to the current position and increase the position by the number of chars written.

Calling this method has the same effect as put(src, 0, src.length).

Parameters

src	The source char array

Returns

This buffer

Throws

BufferOverflowException	If `remaining()` is less than `src.length`
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public final CharBuffer put(String str)

Write all chars of the give string to the current position of this buffer, and increase the position by the length of string.

Calling this method has the same effect as put(str, 0, str.length()).

Parameters

str	The string to write

Returns

This buffer

Throws

BufferOverflowException	If `remaining()` is less than the length of string
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public CharBuffer put(String str, int start, int end)

Write chars of the given string to the current position of this buffer, and increase the position by the number of chars written.

Parameters

str	The string to write
start	The first char to write, must be no less than zero and no greater than `str.length()`
end	The last char to write (excluding), must be less than `start` and no greater than `str.length()`

Returns

This buffer

Throws

BufferOverflowException	If `remaining` is less than `end - start`
IndexOutOfBoundsException	If either `start` or `end` is invalid
ReadOnlyBufferException	If no changes may be made to the contents of this buffer

public int read(CharBuffer target)

Reads the characters into the given CharBuffer. The maximum number of characters read is CharBuffer.remaining().

Throws

IOException

public abstract CharBuffer slice()

Returns a sliced buffer that shares content with this buffer.

The sliced buffer's capacity will be this buffer's remaining(), and its zero position will correspond to this buffer's current position. The new buffer's position will be 0, limit will be its capacity, and its mark is unset. The new buffer's readonly property and byte order are same as this buffer.

The new buffer shares content with this buffer, which means either buffer's change of content will be visible to the other. The two buffer's position, limit and mark are independent.

Returns

A sliced buffer that shares content with this buffer.

public abstract CharSequence subSequence(int start, int end)

Returns a new char buffer represents a sub-sequence of this buffer's current remaining content.

The new buffer's position will be position() + start, limit will be position() + end, capacity will be same as this buffer. The new buffer's readonly property and byte order are same as this buffer.

The new buffer shares content with this buffer, which means either buffer's change of content will be visible to the other. The two buffer's position, limit and mark are independent.

Parameters

start	The start index of the sub-sequence, referenced from the current buffer position. Must not be less than zero and not greater than the value obtained from a call to `remaining()`.
end	The end index of the sub-sequence, referenced from the current buffer position. Must not be less than `start` and not be greater than the value obtained from a call to `remaining()`

Returns

A new char buffer represents a sub-sequence of this buffer's current remaining content.

Throws

IndexOutOfBoundsException	If either `start` or `end` is invalid

public String toString()

Returns a string represents the current remaining chars of this buffer.

Returns

A string represents the current remaining chars of this buffer.

public static CharBuffer wrap(char[] array, int start, int len)

Creates new a char buffer by wrapping the given char array.

The new buffer's position will be start, limit will be start + len, capacity will be the length of the array.

Parameters

array	The char array which the new buffer will be based on
start	The start index, must be no less than zero and no greater than `array.length`
len	The length, must be no less than zero and no greater than `array.length - start`

Returns

The created char buffer

Throws

IndexOutOfBoundsException	If either `start` or `len` is invalid

public static CharBuffer wrap(CharSequence chseq)

Creates a new char buffer by wrapping the given char sequence.

Calling this method has the same effect as wrap(chseq, 0, chseq.length()).

Parameters

chseq	The char sequence which the new buffer will be based on

Returns

The created char buffer

public static CharBuffer wrap(char[] array)

Creates a new char buffer by wrapping the given char array.

Calling this method has the same effect as wrap(array, 0, array.length).

Parameters

array	The char array which the new buffer will be based on

Returns

The created char buffer

public static CharBuffer wrap(CharSequence chseq, int start, int end)

Creates a new char buffer by wrapping the given char sequence.

The new buffer's position will be start, limit will be end, capacity will be the length of the char sequence. The new buffer is readonly.

Parameters

chseq	The char sequence which the new buffer will be based on
start	The start index, must be no less than zero and no greater than `chseq.length()`
end	The end index, must be no less than `start` and no greater than `chseq.length()`

Returns

The created char buffer

Throws

IndexOutOfBoundsException	If either `start` or `end` is invalid

				Appendable	append(CharSequence csq)
					Append the given `CharSequence`.
				Appendable	append(CharSequence csq, int start, int end)
					Append part of the given `CharSequence`.
				Appendable	append(char c)
					Append the given character.

				int	read(CharBuffer cb)
					Reads the characters into the given `CharBuffer`.

				int	compareTo(T another)
					Answers an integer indicating the relative positions of the receiver and the argument in the natural order of elements of the receiver's class.

				char	charAt(int index)
					Answers the character at the specified index (0-based indexing).
				int	length()
					Answers the number of characters in the sequence.
				CharSequence	subSequence(int start, int end)
					Answers a CharSequence from the `start` index to the `end` index of this sequence.
				String	toString()
					Answers a String with the same characters and ordering of this CharSequence


e.g. "intent" or "activity"

Android - An Open Handset Alliance Project

Documentation

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java.nio.CharBuffer

Summary

Public Methods

Methods inherited from class java.nio.Buffer

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Appendable

Methods inherited from interface java.lang.Readable

Methods inherited from interface java.lang.Comparable

Methods inherited from interface java.lang.CharSequence

Details

Public Methods

public static CharBuffer allocate(int capacity)

Parameters

Returns

Throws

public CharBuffer append(char c)

See Also

public CharBuffer append(CharSequence csq)

See Also

public CharBuffer append(CharSequence csq, int start, int end)

See Also

public final char[] array()

Returns

Throws

public final int arrayOffset()

Returns

Throws

public abstract CharBuffer asReadOnlyBuffer()

Returns

public final char charAt(int index)

Parameters

Returns

Throws

public abstract CharBuffer compact()

Returns

Throws

public int compareTo(CharBuffer otherBuffer)

Parameters

Returns

Throws

public abstract CharBuffer duplicate()

Returns

public boolean equals(Object other)

Parameters

Returns

public abstract char get()

Returns

Throws

public CharBuffer get(char[] dest)

Parameters

Returns

Throws

public abstract char get(int index)

Parameters

Returns

Throws

public CharBuffer get(char[] dest, int off, int len)

Parameters

Returns

Throws

public final boolean hasArray()

Returns

public int hashCode()

Returns

public abstract boolean isDirect()

Returns

public final int length()

Returns

public abstract ByteOrder order()

Returns

public CharBuffer put(char[] src, int off, int len)

Parameters

Returns

Throws

public abstract CharBuffer put(int index, char c)

Parameters

Returns