Added in API level 1

Summary: Methods | Inherited Methods

CharBuffer

public abstract class CharBuffer
extends Buffer implements Comparable<CharBuffer>, Appendable, CharSequence, Readable

java.lang.Object
↳	java.nio.Buffer
	↳	java.nio.CharBuffer

A char buffer.

This class defines four categories of operations upon char buffers:

Absolute and relative get and put methods that read and write single chars;
Absolute and relative bulk get methods that transfer contiguous sequences of chars from this buffer into an array; and
Absolute and relative bulk put methods that transfer contiguous sequences of chars from a char array, string, or some other char buffer into this buffer; and
A method for compacting a char buffer.

Char buffers can be created either by allocation, which allocates space for the buffer's content, by wrapping an existing char array or string into a buffer, or by creating a view of an existing byte buffer.

Like a byte buffer, a char buffer is either direct or non-direct. A char buffer created via the wrap methods of this class will be non-direct. A char buffer created as a view of a byte buffer will be direct if, and only if, the byte buffer itself is direct. Whether or not a char buffer is direct may be determined by invoking the isDirect method.

This class implements the CharSequence interface so that character buffers may be used wherever character sequences are accepted, for example in the regular-expression package java.util.regex. The methods defined by CharSequence operate relative to the current position of the buffer when they are invoked.

Methods in this class that do not otherwise have a value to return are specified to return the buffer upon which they are invoked. This allows method invocations to be chained. The sequence of statements

 cb.put("text/");
 cb.put(subtype);
 cb.put("; charset=");
 cb.put(enc);

can, for example, be replaced by the single statement

 cb.put("text/").put(subtype).put("; charset=").put(enc);

Summary

Public methods
`static CharBuffer`	`allocate(int capacity)` Allocates a new char buffer.
`CharBuffer`	`append(char c)` Appends the specified char to this buffer (optional operation).
`CharBuffer`	`append(CharSequence csq, int start, int end)` Appends a subsequence of the specified character sequence to this buffer (optional operation).
`CharBuffer`	`append(CharSequence csq)` Appends the specified character sequence to this buffer (optional operation).
`final char[]`	`array()` Returns the char array that backs this buffer (optional operation).
`final int`	`arrayOffset()` Returns the offset within this buffer's backing array of the first element of the buffer (optional operation).
`abstract CharBuffer`	`asReadOnlyBuffer()` Creates a new, read-only char buffer that shares this buffer's content.
`final char`	`charAt(int index)` Reads the character at the given index relative to the current position.
`IntStream`	`chars()` Returns a stream of `int` zero-extending the `char` values from this sequence.
`Buffer`	`clear()` Clears this buffer.
`abstract CharBuffer`	`compact()` Compacts this buffer (optional operation).
`int`	`compareTo(CharBuffer that)` Compares this buffer to another.
`abstract CharBuffer`	`duplicate()` Creates a new char buffer that shares this buffer's content.
`boolean`	`equals(Object ob)` Tells whether or not this buffer is equal to another object.
`Buffer`	`flip()` Flips this buffer.
`abstract char`	`get()` Relative get method.
`CharBuffer`	`get(int index, char[] dst)` Absolute bulk get method.
`CharBuffer`	`get(char[] dst)` Relative bulk get method.
`CharBuffer`	`get(char[] dst, int offset, int length)` Relative bulk get method.
`CharBuffer`	`get(int index, char[] dst, int offset, int length)` Absolute bulk get method.
`abstract char`	`get(int index)` Absolute get method.
`final boolean`	`hasArray()` Tells whether or not this buffer is backed by an accessible char array.
`int`	`hashCode()` Returns the current hash code of this buffer.
`abstract boolean`	`isDirect()` Tells whether or not this char buffer is direct.
`final boolean`	`isEmpty()` Returns `true` if this character buffer is empty.
`final int`	`length()` Returns the length of this character buffer.
`Buffer`	`limit(int newLimit)` Sets this buffer's limit.
`Buffer`	`mark()` Sets this buffer's mark at its position.
`int`	`mismatch(CharBuffer that)` Finds and returns the relative index of the first mismatch between this buffer and a given buffer.
`abstract ByteOrder`	`order()` Retrieves this buffer's byte order.
`Buffer`	`position(int newPosition)` Sets this buffer's position.
`final CharBuffer`	`put(char[] src)` Relative bulk put method (optional operation).
`CharBuffer`	`put(int index, char[] src)` Absolute bulk put method (optional operation).
`abstract CharBuffer`	`put(int index, char c)` Absolute put method (optional operation).
`CharBuffer`	`put(CharBuffer src)` Relative bulk put method (optional operation).
`abstract CharBuffer`	`put(char c)` Relative put method (optional operation).
`CharBuffer`	`put(int index, char[] src, int offset, int length)` Absolute bulk put method (optional operation).
`CharBuffer`	`put(char[] src, int offset, int length)` Relative bulk put method (optional operation).
`final CharBuffer`	`put(String src)` Relative bulk put method (optional operation).
`CharBuffer`	`put(String src, int start, int end)` Relative bulk put method (optional operation).
`CharBuffer`	`put(int index, CharBuffer src, int offset, int length)` Absolute bulk put method (optional operation).
`int`	`read(CharBuffer target)` Attempts to read characters into the specified character buffer.
`Buffer`	`reset()` Resets this buffer's position to the previously-marked position.
`Buffer`	`rewind()` Rewinds this buffer.
`abstract CharBuffer`	`slice()` Creates a new char buffer whose content is a shared subsequence of this buffer's content.
`abstract CharBuffer`	`slice(int index, int length)` Creates a new char buffer whose content is a shared subsequence of this buffer's content.
`abstract CharBuffer`	`subSequence(int start, int end)` Creates a new character buffer that represents the specified subsequence of this buffer, relative to the current position.
`String`	`toString()` Returns a string containing the characters in this buffer.
`static CharBuffer`	`wrap(CharSequence csq)` Wraps a character sequence into a buffer.
`static CharBuffer`	`wrap(char[] array, int offset, int length)` Wraps a char array into a buffer.
`static CharBuffer`	`wrap(CharSequence csq, int start, int end)` Wraps a character sequence into a buffer.
`static CharBuffer`	`wrap(char[] array)` Wraps a char array into a buffer.

Inherited methods

From class


        
          java.nio.Buffer

`abstract Object`	`array()` Returns the array that backs this buffer (optional operation).
`abstract int`	`arrayOffset()` Returns the offset within this buffer's backing array of the first element of the buffer (optional operation).
`final int`	`capacity()` Returns this buffer's capacity.
`Buffer`	`clear()` Clears this buffer.
`abstract Buffer`	`duplicate()` Creates a new buffer that shares this buffer's content.
`Buffer`	`flip()` Flips this buffer.
`abstract boolean`	`hasArray()` Tells whether or not this buffer is backed by an accessible array.
`final boolean`	`hasRemaining()` Tells whether there are any elements between the current position and the limit.
`abstract boolean`	`isDirect()` Tells whether or not this buffer is direct.
`abstract boolean`	`isReadOnly()` Tells whether or not this buffer is read-only.
`final int`	`limit()` Returns this buffer's limit.
`Buffer`	`limit(int newLimit)` Sets this buffer's limit.
`Buffer`	`mark()` Sets this buffer's mark at its position.
`Buffer`	`position(int newPosition)` Sets this buffer's position.
`final int`	`position()` Returns this buffer's position.
`final int`	`remaining()` Returns the number of elements between the current position and the limit.
`Buffer`	`reset()` Resets this buffer's position to the previously-marked position.
`Buffer`	`rewind()` Rewinds this buffer.
`abstract Buffer`	`slice(int index, int length)` Creates a new buffer whose content is a shared subsequence of this buffer's content.
`abstract Buffer`	`slice()` Creates a new buffer whose content is a shared subsequence of this buffer's content.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.lang.Comparable


      compareTo(CharBuffer o)

Compares this object with the specified object for order.

From interface


        
          java.lang.Appendable

`abstract Appendable`	`append(char c)` Appends the specified character to this `Appendable`.
`abstract Appendable`	`append(CharSequence csq, int start, int end)` Appends a subsequence of the specified character sequence to this `Appendable`.
`abstract Appendable`	`append(CharSequence csq)` Appends the specified character sequence to this `Appendable`.

From interface


        
          java.lang.CharSequence

`abstract char`	`charAt(int index)` Returns the `char` value at the specified index.
`default IntStream`	`chars()` Returns a stream of `int` zero-extending the `char` values from this sequence.
`default IntStream`	`codePoints()` Returns a stream of code point values from this sequence.
`static int`	`compare(CharSequence cs1, CharSequence cs2)` Compares two `CharSequence` instances lexicographically.
`default boolean`	`isEmpty()` Returns `true` if this character sequence is empty.
`abstract int`	`length()` Returns the length of this character sequence.
`abstract CharSequence`	`subSequence(int start, int end)` Returns a `CharSequence` that is a subsequence of this sequence.
`abstract String`	`toString()` Returns a string containing the characters in this sequence in the same order as this sequence.

From interface


        
          java.lang.Readable


      read(CharBuffer cb)

Attempts to read characters into the specified character buffer.

Public methods

allocate

Added in API level 1

public static CharBuffer allocate (int capacity)

Allocates a new char buffer.

The new buffer's position will be zero, its limit will be its capacity, its mark will be undefined, each of its elements will be initialized to zero, and its byte order will be the native order of the underlying hardware. It will have a backing array, and its array offset will be zero.

Parameters
`capacity`	`int`: The new buffer's capacity, in chars

Returns
`CharBuffer`	The new char buffer

Throws
`IllegalArgumentException`	If the `capacity` is a negative integer

append

Added in API level 1

public CharBuffer append (char c)

Appends the specified char to this buffer (optional operation).

An invocation of this method of the form dst.append(c) behaves in exactly the same way as the invocation

     dst.put(c)

Parameters
`c`	`char`: The 16-bit char to append

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`ReadOnlyBufferException`	If this buffer is read-only

append

Added in API level 1

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

Appends a subsequence of the specified character sequence to this buffer (optional operation).

An invocation of this method of the form dst.append(csq, start, end) when csq is not null, behaves in exactly the same way as the invocation

     dst.put(csq.subSequence(start, end).toString())

Parameters
`csq`	`CharSequence`: The character sequence from which a subsequence will be appended. If `csq` is `null`, then characters will be appended as if `csq` contained the four characters `"null"`.
`start`	`int`: The index of the first character in the subsequence
`end`	`int`: The index of the character following the last character in the subsequence

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`IndexOutOfBoundsException`	If `start` or `end` are negative, `start` is greater than `end`, or `end` is greater than `csq.length()`
`ReadOnlyBufferException`	If this buffer is read-only

append

Added in API level 1

public CharBuffer append (CharSequence csq)

Appends the specified character sequence to this buffer (optional operation).

An invocation of this method of the form dst.append(csq) behaves in exactly the same way as the invocation

     dst.put(csq.toString())

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Parameters
`csq`	`CharSequence`: The character sequence to append. If `csq` is `null`, then the four characters `"null"` are appended to this character buffer.

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`ReadOnlyBufferException`	If this buffer is read-only

array

Added in API level 1

public final char[] array ()

Returns the char array that backs this buffer (optional operation).

Modifications to this buffer's content will cause the returned array's content to be modified, and vice versa.

Invoke the hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

Returns
`char[]`	The array that backs this buffer

Throws
`ReadOnlyBufferException`	If this buffer is backed by an array but is read-only
`UnsupportedOperationException`	If this buffer is not backed by an accessible array

arrayOffset

Added in API level 1

public final int arrayOffset ()

Returns the offset within this buffer's backing array of the first element of the buffer (optional operation).

If this buffer is backed by an array then buffer position p corresponds to array index p + arrayOffset().

Invoke the hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

Returns
`int`	The offset within this buffer's array of the first element of the buffer

Throws
`ReadOnlyBufferException`	If this buffer is backed by an array but is read-only
`UnsupportedOperationException`	If this buffer is not backed by an accessible array

asReadOnlyBuffer

Added in API level 1

public abstract CharBuffer asReadOnlyBuffer ()

Creates a new, read-only char buffer that shares this buffer's content.

The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer; the new buffer itself, however, will be read-only and will not allow the shared content to be modified. The two buffers' position, limit, and mark values will be independent.

The new buffer's capacity, limit, position, mark values, and byte order will be identical to those of this buffer.

If this buffer is itself read-only then this method behaves in exactly the same way as the duplicate method.

Returns
`CharBuffer`	The new, read-only char buffer

charAt

Added in API level 1

public final char charAt (int index)

Reads the character at the given index relative to the current position.

Parameters
`index`	`int`: The index of the character to be read, relative to the position; must be non-negative and smaller than `remaining()`

Returns
`char`	The character at index `position() + index`

Throws
`IndexOutOfBoundsException`	If the preconditions on `index` do not hold

chars

Added in API level 24

public IntStream chars ()

Returns a stream of int zero-extending the char values from this sequence. Any char which maps to a surrogate code point is passed through uninterpreted.

The stream binds to this sequence when the terminal stream operation commences (specifically, for mutable sequences the spliterator for the stream is late-binding). If the sequence is modified during that operation then the result is undefined.

Returns
`IntStream`	an IntStream of char values from this sequence

clear

Added in API level 1

public Buffer clear ()

Clears this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded.

Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example:

 buf.clear();     // Prepare buffer for reading
 in.read(buf);    // Read data

This method does not actually erase the data in the buffer, but it is named as if it did because it will most often be used in situations in which that might as well be the case.

Returns
`Buffer`	This buffer

compact

Added in API level 1

public abstract CharBuffer compact ()

Compacts this buffer (optional operation).

The chars between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the char at index p = position() is copied to index zero, the char at index p + 1 is copied to index one, and so forth until the char at index limit() - 1 is copied to index n = limit() - 1 - p. The buffer's position is then set to n+1 and its limit is set to its capacity. The mark, if defined, is discarded.

The buffer's position is set to the number of chars copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method.

Returns
`CharBuffer`	This buffer

Throws
`ReadOnlyBufferException`	If this buffer is read-only

compareTo

Added in API level 1

public int compareTo (CharBuffer that)

Compares this buffer to another.

Two char buffers are compared by comparing their sequences of remaining elements lexicographically, without regard to the starting position of each sequence within its corresponding buffer. Pairs of char elements are compared as if by invoking Character#compare(char,char).

A char buffer is not comparable to any other type of object.

Parameters
`that`	`CharBuffer`

Returns
`int`	A negative integer, zero, or a positive integer as this buffer is less than, equal to, or greater than the given buffer

duplicate

Added in API level 1

public abstract CharBuffer duplicate ()

Creates a new char buffer that shares this buffer's content.

The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

The new buffer's capacity, limit, position, mark values, and byte order will be identical to those of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Returns
`CharBuffer`	The new char buffer

equals

Added in API level 1

public boolean equals (Object ob)

Tells whether or not this buffer is equal to another object.

Two char buffers are equal if, and only if,

They have the same element type,
They have the same number of remaining elements, and
The two sequences of remaining elements, considered independently of their starting positions, are pointwise equal.

A char buffer is not equal to any other type of object.

Parameters
`ob`	`Object`: The object to which this buffer is to be compared

Returns
`boolean`	`true` if, and only if, this buffer is equal to the given object

flip

Added in API level 1

public Buffer flip ()

Flips this buffer. The limit is set to the current position and then the position is set to zero. If the mark is defined then it is discarded.

After a sequence of channel-read or put operations, invoke this method to prepare for a sequence of channel-write or relative get operations. For example:

 buf.put(magic);    // Prepend header
 in.read(buf);      // Read data into rest of buffer
 buf.flip();        // Flip buffer
 out.write(buf);    // Write header + data to channel

This method is often used in conjunction with the compact method when transferring data from one place to another.

Returns
`Buffer`	This buffer

get

Added in API level 1

public abstract char get ()

Relative get method. Reads the char at this buffer's current position, and then increments the position.

Returns
`char`	The char at the buffer's current position

Throws
`BufferUnderflowException`	If the buffer's current position is not smaller than its limit

get

Added in API level 35

public CharBuffer get (int index, 
                char[] dst)

Absolute bulk get method.

This method transfers chars from this buffer into the given destination array. The position of this buffer is unchanged. An invocation of this method of the form src.get(index, dst) behaves in exactly the same way as the invocation:

     src.get(index, dst, 0, dst.length)

Parameters
`index`	`int`: The index in this buffer from which the first char will be read; must be non-negative and less than `limit()`
`dst`	`char`: The destination array

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If `index` is negative, not smaller than `limit()`, or `limit() - index < dst.length`

get

Added in API level 1

public CharBuffer get (char[] dst)

Relative bulk get method.

This method transfers chars from this buffer into the given destination array. An invocation of this method of the form src.get(a) behaves in exactly the same way as the invocation

     src.get(a, 0, a.length)

Parameters
`dst`	`char`: The destination array

Returns
`CharBuffer`	This buffer

Throws
`BufferUnderflowException`	If there are fewer than `length` chars remaining in this buffer

get

Added in API level 1

public CharBuffer get (char[] dst, 
                int offset, 
                int length)

Relative bulk get method.

This method transfers chars from this buffer into the given destination array. If there are fewer chars remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no chars are transferred and a BufferUnderflowException is thrown.

Otherwise, this method copies length chars from this buffer into the given array, starting at the current position of this buffer and at the given offset in the array. The position of this buffer is then incremented by length.

In other words, an invocation of this method of the form src.get(dst, off, len) has exactly the same effect as the loop

for (int i = off; i < off + len; i++)
         dst[i] = src.get();

except that it first checks that there are sufficient chars in this buffer and it is potentially much more efficient.

Parameters
`dst`	`char`: The array into which chars are to be written
`offset`	`int`: The offset within the array of the first char to be written; must be non-negative and no larger than `dst.length`
`length`	`int`: The maximum number of chars to be written to the given array; must be non-negative and no larger than `dst.length - offset`

Returns
`CharBuffer`	This buffer

Throws
`BufferUnderflowException`	If there are fewer than `length` chars remaining in this buffer
`IndexOutOfBoundsException`	If the preconditions on the `offset` and `length` parameters do not hold

get

Added in API level 35

public CharBuffer get (int index, 
                char[] dst, 
                int offset, 
                int length)

Absolute bulk get method.

This method transfers length chars from this buffer into the given array, starting at the given index in this buffer and at the given offset in the array. The position of this buffer is unchanged.

An invocation of this method of the form src.get(index, dst, offset, length) has exactly the same effect as the following loop except that it first checks the consistency of the supplied parameters and it is potentially much more efficient:

for (int i = offset, j = index; i < offset + length; i++, j++)
         dst[i] = src.get(j);

Parameters
`index`	`int`: The index in this buffer from which the first char will be read; must be non-negative and less than `limit()`
`dst`	`char`: The destination array
`offset`	`int`: The offset within the array of the first char to be written; must be non-negative and less than `dst.length`
`length`	`int`: The number of chars to be written to the given array; must be non-negative and no larger than the smaller of `limit() - index` and `dst.length - offset`

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on the `index`, `offset`, and `length` parameters do not hold

get

Added in API level 1

public abstract char get (int index)

Absolute get method. Reads the char at the given index.

Parameters
`index`	`int`: The index from which the char will be read

Returns
`char`	The char at the given index

Throws
`IndexOutOfBoundsException`	If `index` is negative or not smaller than the buffer's limit

hasArray

Added in API level 1

public final boolean hasArray ()

Tells whether or not this buffer is backed by an accessible char array.

If this method returns true then the array and arrayOffset methods may safely be invoked.

Returns
`boolean`	`true` if, and only if, this buffer is backed by an array and is not read-only

hashCode

Added in API level 1

public int hashCode ()

Returns the current hash code of this buffer.

The hash code of a char buffer depends only upon its remaining elements; that is, upon the elements from position() up to, and including, the element at limit() - 1.

Because buffer hash codes are content-dependent, it is inadvisable to use buffers as keys in hash maps or similar data structures unless it is known that their contents will not change.

Returns
`int`	The current hash code of this buffer

isDirect

Added in API level 1

public abstract boolean isDirect ()

Tells whether or not this char buffer is direct.

Returns
`boolean`	`true` if, and only if, this buffer is direct

isEmpty

Added in API level 34

public final boolean isEmpty ()

Returns true if this character buffer is empty.

Returns
`boolean`	`true` if there are `0` remaining characters, otherwise `false`

length

Added in API level 1

public final int length ()

Returns the length of this character buffer.

When viewed as a character sequence, the length of a character buffer is simply the number of characters between the position (inclusive) and the limit (exclusive); that is, it is equivalent to remaining().

Returns
`int`	The length of this character buffer

limit

Added in API level 1

public Buffer limit (int newLimit)

Sets this buffer's limit. If the position is larger than the new limit then it is set to the new limit. If the mark is defined and larger than the new limit then it is discarded.

Parameters
`newLimit`	`int`: The new limit value; must be non-negative and no larger than this buffer's capacity

Returns
`Buffer`	This buffer

mark

Added in API level 1

public Buffer mark ()

Sets this buffer's mark at its position.

Returns
`Buffer`	This buffer

mismatch

Added in API level 34

public int mismatch (CharBuffer that)

Finds and returns the relative index of the first mismatch between this buffer and a given buffer. The index is relative to the position of each buffer and will be in the range of 0 (inclusive) up to the smaller of the remaining elements in each buffer (exclusive).

If the two buffers share a common prefix then the returned index is the length of the common prefix and it follows that there is a mismatch between the two buffers at that index within the respective buffers. If one buffer is a proper prefix of the other then the returned index is the smaller of the remaining elements in each buffer, and it follows that the index is only valid for the buffer with the larger number of remaining elements. Otherwise, there is no mismatch.

Parameters
`that`	`CharBuffer`: The byte buffer to be tested for a mismatch with this buffer

Returns
`int`	The relative index of the first mismatch between this and the given buffer, otherwise -1 if no mismatch.

order

Added in API level 1

public abstract ByteOrder order ()

Retrieves this buffer's byte order.

The byte order of a char buffer created by allocation or by wrapping an existing char array is the native order of the underlying hardware. The byte order of a char buffer created as a view of a byte buffer is that of the byte buffer at the moment that the view is created.

Returns
`ByteOrder`	This buffer's byte order

position

Added in API level 1

public Buffer position (int newPosition)

Sets this buffer's position. If the mark is defined and larger than the new position then it is discarded.

Parameters
`newPosition`	`int`: The new position value; must be non-negative and no larger than the current limit

Returns
`Buffer`	This buffer

put

Added in API level 1

public final CharBuffer put (char[] src)

Relative bulk put method (optional operation).

This method transfers the entire content of the given source char array into this buffer. An invocation of this method of the form dst.put(a) behaves in exactly the same way as the invocation

     dst.put(a, 0, a.length)

Parameters
`src`	`char`: The source array

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 35

public CharBuffer put (int index, 
                char[] src)

Absolute bulk put method (optional operation).

This method copies chars into this buffer from the given source array. The position of this buffer is unchanged. An invocation of this method of the form dst.put(index, src) behaves in exactly the same way as the invocation:

     dst.put(index, src, 0, src.length);

Parameters
`index`	`int`: The index in this buffer at which the first char will be written; must be non-negative and less than `limit()`
`src`	`char`: The array from which chars are to be read

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If `index` is negative, not smaller than `limit()`, or `limit() - index < src.length`
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

public abstract CharBuffer put (int index, 
                char c)

Absolute put method (optional operation).

Writes the given char into this buffer at the given index.

Parameters
`index`	`int`: The index at which the char will be written
`c`	`char`: The char value to be written

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If `index` is negative or not smaller than the buffer's limit
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

public CharBuffer put (CharBuffer src)

Relative bulk put method (optional operation).

This method transfers the chars remaining in the given source buffer into this buffer. If there are more chars remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(), then no chars are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies n = src.remaining() chars from the given buffer into this buffer, starting at each buffer's current position. The positions of both buffers are then incremented by n.

In other words, an invocation of this method of the form dst.put(src) has exactly the same effect as the loop

     while (src.hasRemaining())
         dst.put(src.get());

except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.

Parameters
`src`	`CharBuffer`: The source buffer from which chars are to be read; must not be this buffer

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer for the remaining chars in the source buffer
`IllegalArgumentException`	If the source buffer is this buffer
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

public abstract CharBuffer put (char c)

Relative put method (optional operation).

Writes the given char into this buffer at the current position, and then increments the position.

Parameters
`c`	`char`: The char to be written

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If this buffer's current position is not smaller than its limit
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 35

public CharBuffer put (int index, 
                char[] src, 
                int offset, 
                int length)

Absolute bulk put method (optional operation).

This method transfers length chars from the given array, starting at the given offset in the array and at the given index in this buffer. The position of this buffer is unchanged.

An invocation of this method of the form dst.put(index, src, offset, length) has exactly the same effect as the following loop except that it first checks the consistency of the supplied parameters and it is potentially much more efficient:

for (int i = offset, j = index; i < offset + length; i++, j++)
         dst.put(j, src[i]);

Parameters
`index`	`int`: The index in this buffer at which the first char will be written; must be non-negative and less than `limit()`
`src`	`char`: The array from which chars are to be read
`offset`	`int`: The offset within the array of the first char to be read; must be non-negative and less than `src.length`
`length`	`int`: The number of chars to be read from the given array; must be non-negative and no larger than the smaller of `limit() - index` and `src.length - offset`

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on the `index`, `offset`, and `length` parameters do not hold
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

public CharBuffer put (char[] src, 
                int offset, 
                int length)

Relative bulk put method (optional operation).

This method transfers chars into this buffer from the given source array. If there are more chars to be copied from the array than remain in this buffer, that is, if length > remaining(), then no chars are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies length chars from the given array into this buffer, starting at the given offset in the array and at the current position of this buffer. The position of this buffer is then incremented by length.

In other words, an invocation of this method of the form dst.put(src, off, len) has exactly the same effect as the loop

for (int i = off; i < off + len; i++)
         dst.put(src[i]);

except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

Parameters
`src`	`char`: The array from which chars are to be read
`offset`	`int`: The offset within the array of the first char to be read; must be non-negative and no larger than `src.length`
`length`	`int`: The number of chars to be read from the given array; must be non-negative and no larger than `src.length - offset`

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`IndexOutOfBoundsException`	If the preconditions on the `offset` and `length` parameters do not hold
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

public final CharBuffer put (String src)

Relative bulk put method (optional operation).

This method transfers the entire content of the given source string into this buffer. An invocation of this method of the form dst.put(s) behaves in exactly the same way as the invocation

     dst.put(s, 0, s.length())

Parameters
`src`	`String`: The source string

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 1

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

Relative bulk put method (optional operation).

This method transfers chars from the given string into this buffer. If there are more chars to be copied from the string than remain in this buffer, that is, if end - start > remaining(), then no chars are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies n = end - start chars from the given string into this buffer, starting at the given start index and at the current position of this buffer. The position of this buffer is then incremented by n.

In other words, an invocation of this method of the form dst.put(src, start, end) has exactly the same effect as the loop

for (int i = start; i < end; i++)
         dst.put(src.charAt(i));

except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

Parameters
`src`	`String`: The string from which chars are to be read
`start`	`int`: The offset within the string of the first char to be read; must be non-negative and no larger than `string.length()`
`end`	`int`: The offset within the string of the last char to be read, plus one; must be non-negative and no larger than `string.length()`

Returns
`CharBuffer`	This buffer

Throws
`BufferOverflowException`	If there is insufficient space in this buffer
`IndexOutOfBoundsException`	If the preconditions on the `start` and `end` parameters do not hold
`ReadOnlyBufferException`	If this buffer is read-only

put

Added in API level 35

public CharBuffer put (int index, 
                CharBuffer src, 
                int offset, 
                int length)

Absolute bulk put method (optional operation).

This method transfers length chars into this buffer from the given source buffer, starting at the given offset in the source buffer and the given index in this buffer. The positions of both buffers are unchanged.

In other words, an invocation of this method of the form dst.put(index, src, offset, length) has exactly the same effect as the loop

for (int i = offset, j = index; i < offset + length; i++, j++)
     dst.put(j, src.get(i));

except that it first checks the consistency of the supplied parameters and it is potentially much more efficient. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.

Parameters
`index`	`int`: The index in this buffer at which the first char will be written; must be non-negative and less than `limit()`
`src`	`CharBuffer`: The buffer from which chars are to be read
`offset`	`int`: The index within the source buffer of the first char to be read; must be non-negative and less than `src.limit()`
`length`	`int`: The number of chars to be read from the given buffer; must be non-negative and no larger than the smaller of `limit() - index` and `src.limit() - offset`

Returns
`CharBuffer`	This buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on the `index`, `offset`, and `length` parameters do not hold
`ReadOnlyBufferException`	If this buffer is read-only

read

Added in API level 1

public int read (CharBuffer target)

Attempts to read characters into the specified character buffer. The buffer is used as a repository of characters as-is: the only changes made are the results of a put operation. No flipping or rewinding of the buffer is performed.

Parameters
`target`	`CharBuffer`: the buffer to read characters into

Returns
`int`	The number of characters added to the buffer, or -1 if this source of characters is at its end

Throws
`IOException`	if an I/O error occurs
`NullPointerException`	if target is null
`ReadOnlyBufferException`	if target is a read only buffer

reset

Added in API level 1

public Buffer reset ()

Resets this buffer's position to the previously-marked position.

Invoking this method neither changes nor discards the mark's value.

Returns
`Buffer`	This buffer

rewind

Added in API level 1

public Buffer rewind ()

Rewinds this buffer. The position is set to zero and the mark is discarded.

Invoke this method before a sequence of channel-write or get operations, assuming that the limit has already been set appropriately. For example:

 out.write(buf);    // Write remaining data
 buf.rewind();      // Rewind buffer
 buf.get(array);    // Copy data into array

Returns
`Buffer`	This buffer

slice

Added in API level 1

public abstract CharBuffer slice ()

Creates a new char buffer whose content is a shared subsequence of this buffer's content.

The content of the new buffer will start at this buffer's current position. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

The new buffer's position will be zero, its capacity and its limit will be the number of chars remaining in this buffer, its mark will be undefined, and its byte order will be identical to that of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Returns
`CharBuffer`	The new char buffer

slice

Added in API level 34

public abstract CharBuffer slice (int index, 
                int length)

Creates a new char buffer whose content is a shared subsequence of this buffer's content.

The content of the new buffer will start at position index in this buffer, and will contain length elements. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

The new buffer's position will be zero, its capacity and its limit will be length, its mark will be undefined, and its byte order will be identical to that of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Parameters
`index`	`int`: The position in this buffer at which the content of the new buffer will start; must be non-negative and no larger than `limit()`
`length`	`int`: The number of elements the new buffer will contain; must be non-negative and no larger than `limit() - index`

Returns
`CharBuffer`	The new buffer

Throws
`IndexOutOfBoundsException`	If `index` is negative or greater than `limit()`, `length` is negative, or `length > limit() - index`

subSequence

Added in API level 1

public abstract CharBuffer subSequence (int start, 
                int end)

Creates a new character buffer that represents the specified subsequence of this buffer, relative to the current position.

The new buffer will share this buffer's content; that is, if the content of this buffer is mutable then modifications to one buffer will cause the other to be modified. The new buffer's capacity will be that of this buffer, its position will be position() + start, its limit will be position() + end, and its byte order will be identical to that of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Parameters
`start`	`int`: The index, relative to the current position, of the first character in the subsequence; must be non-negative and no larger than `remaining()`
`end`	`int`: The index, relative to the current position, of the character following the last character in the subsequence; must be no smaller than `start` and no larger than `remaining()`

Returns
`CharBuffer`	The new character buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on `start` and `end` do not hold

toString

Added in API level 1

public String toString ()

Returns a string containing the characters in this buffer.

The first character of the resulting string will be the character at this buffer's position, while the last character will be the character at index limit() - 1. Invoking this method does not change the buffer's position.

Returns
`String`	The specified string

wrap

Added in API level 1

public static CharBuffer wrap (CharSequence csq)

Wraps a character sequence into a buffer.

The content of the new, read-only buffer will be the content of the given character sequence. The new buffer's capacity and limit will be csq.length(), its position will be zero, and its mark will be undefined.

Parameters
`csq`	`CharSequence`: The character sequence from which the new character buffer is to be created

Returns
`CharBuffer`	The new character buffer

wrap

Added in API level 1

public static CharBuffer wrap (char[] array, 
                int offset, 
                int length)

Wraps a char array into a buffer.

The new buffer will be backed by the given char array; that is, modifications to the buffer will cause the array to be modified and vice versa. The new buffer's capacity will be array.length, its position will be offset, its limit will be offset + length, its mark will be undefined, and its byte order will be the native order of the underlying hardware. Its backing array will be the given array, and its array offset will be zero.

Parameters
`array`	`char`: The array that will back the new buffer
`offset`	`int`: The offset of the subarray to be used; must be non-negative and no larger than `array.length`. The new buffer's position will be set to this value.
`length`	`int`: The length of the subarray to be used; must be non-negative and no larger than `array.length - offset`. The new buffer's limit will be set to `offset + length`.

Returns
`CharBuffer`	The new char buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on the `offset` and `length` parameters do not hold

wrap

Added in API level 1

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

Wraps a character sequence into a buffer.

The content of the new, read-only buffer will be the content of the given character sequence. The buffer's capacity will be csq.length(), its position will be start, its limit will be end, and its mark will be undefined.

Parameters
`csq`	`CharSequence`: The character sequence from which the new character buffer is to be created
`start`	`int`: The index of the first character to be used; must be non-negative and no larger than `csq.length()`. The new buffer's position will be set to this value.
`end`	`int`: The index of the character following the last character to be used; must be no smaller than `start` and no larger than `csq.length()`. The new buffer's limit will be set to this value.

Returns
`CharBuffer`	The new character buffer

Throws
`IndexOutOfBoundsException`	If the preconditions on the `start` and `end` parameters do not hold

wrap

Added in API level 1

public static CharBuffer wrap (char[] array)

Wraps a char array into a buffer.

The new buffer will be backed by the given char array; that is, modifications to the buffer will cause the array to be modified and vice versa. The new buffer's capacity and limit will be array.length, its position will be zero, its mark will be undefined, and its byte order will be the native order of the underlying hardware. Its backing array will be the given array, and its array offset will be zero.

Parameters
`array`	`char`: The array that will back this buffer

Returns
`CharBuffer`	The new char buffer