ByteBuf

All Known Implementing Classes:

ByteBufNIO
```
public interface ByteBuf
```
An interface wrapper around a java.nio.ByteBuffer which additionally is Closeable, so that pooled byte buffers know how.

This interface is not frozen yet, and methods may be added in a minor release, so beware implementing this yourself.

Since:

3.0

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`byte[]`	`array()`	Returns the byte array that backs this buffer (optional operation).
`ByteBuffer`	`asNIO()`	Gets the underlying NIO `ByteBuffer`.
`ByteBuf`	`asReadOnly()`	Creates a new, read-only byte buffer that shares this buffer's content.
`int`	`capacity()`	Returns this buffer's capacity.
`ByteBuf`	`clear()`	Clears this buffer.
`ByteBuf`	`duplicate()`	Creates a new byte buffer that shares this buffer's content.
`ByteBuf`	`flip()`	Flips this buffer.
`byte`	`get()`	Relative get method.
`ByteBuf`	`get(byte[] bytes)`	Relative bulk `get` method.
`ByteBuf`	`get(byte[] bytes, int offset, int length)`	Relative bulk get method.
`byte`	`get(int index)`	Absolute get method.
`ByteBuf`	`get(int index, byte[] bytes)`	Absolute bulk `get` method.
`ByteBuf`	`get(int index, byte[] bytes, int offset, int length)`	Absolute bulk get method.
`double`	`getDouble()`	Relative get method for reading a double value.
`double`	`getDouble(int index)`	Absolute get method for reading a double value.
`int`	`getInt()`	Relative get method for reading an int value.
`int`	`getInt(int index)`	Absolute get method for reading an int value.
`long`	`getLong()`	Relative get method for reading a long value.
`long`	`getLong(int index)`	Absolute get method for reading a long value.
`int`	`getReferenceCount()`	Gets the current reference count, which starts at 0.
`boolean`	`hasRemaining()`	States whether there are any elements between the current position and the limit.
`int`	`limit()`	Returns this buffer's limit.
`ByteBuf`	`limit(int newLimit)`	Sets this buffer's limit.
`ByteBuf`	`order(ByteOrder byteOrder)`	Modifies this buffer's byte order.
`int`	`position()`	Returns this buffer's position.
`ByteBuf`	`position(int newPosition)`	Sets this buffer's position.
`ByteBuf`	`put(byte b)`	Relative put method (optional operation).
`ByteBuf`	`put(byte[] src, int offset, int length)`	Relative bulk put method (optional operation).
`ByteBuf`	`put(int index, byte b)`	Absolute put method (optional operation).
`void`	`release()`	Release a reference to this object.
`int`	`remaining()`	Returns the number of elements between the current position and the limit.
`ByteBuf`	`retain()`	Retain an additional reference to this object.

- Method Detail
  - capacity
```
int capacity()
```
    Returns this buffer's capacity.
    
    Returns:
    
    The capacity of this buffer
  - put
```
ByteBuf put(int index,
            byte b)
```
    Absolute put method (optional operation).
    
    Writes the given byte into this buffer at the given index.
    
    Parameters:
    
    index - The index at which the byte will be written
    
    b - The byte value to be written
    
    Returns:
    
    This buffer
    
    Throws:
    
    IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit
    
    ReadOnlyBufferException - If this buffer is read-only
  - remaining
```
int remaining()
```
    Returns the number of elements between the current position and the limit.
    
    Returns:
    
    The number of elements remaining in this buffer
  - put
```
ByteBuf put(byte[] src,
            int offset,
            int length)
```
    Relative bulk put method (optional operation).
    
    This method transfers bytes into this buffer from the given source array. If there are more bytes to be copied from the array than remain in this buffer, that is, if length > remaining(), then no bytes are transferred and a BufferOverflowException is thrown.
    
    Otherwise, this method copies length bytes 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(a[i]);
     }
 
```
    except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.
    Parameters:
    
    src - The array from which bytes are to be read
    
    offset - The offset within the array of the first byte to be read; must be non-negative and no larger than array.length
    
    length - The number of bytes to be read from the given array; must be non-negative and no larger than array.length - offset
    
    Returns:
    
    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
  - hasRemaining
```
boolean hasRemaining()
```
    States whether there are any elements between the current position and the limit.
    
    Returns:
    
    true if, and only if, there is at least one element remaining in this buffer
  - put
```
ByteBuf put(byte b)
```
    Relative put method (optional operation).
    
    Writes the given byte into this buffer at the current position, and then increments the position.
    
    Parameters:
    
    b - The byte to be written
    
    Returns:
    
    This buffer
    
    Throws:
    
    BufferOverflowException - If this buffer's current position is not smaller than its limit
    
    ReadOnlyBufferException - If this buffer is read-only
  - flip
```
ByteBuf 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:
    
    This buffer
  - array
```
byte[] array()
```
    Returns the byte 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.
    
    Returns:
    
    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
  - limit
```
int limit()
```
    Returns this buffer's limit.
    
    Returns:
    
    The limit of this buffer
  - position
```
ByteBuf 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 - The new position value; must be non-negative and no larger than the current limit
    
    Returns:
    
    This buffer
    
    Throws:
    
    IllegalArgumentException - If the preconditions on newPosition do not hold
  - clear
```
ByteBuf 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:
    
    This buffer
  - order
```
ByteBuf order(ByteOrder byteOrder)
```
    Modifies this buffer's byte order.
    
    Parameters:
    
    byteOrder - The new byte order, either BIG_ENDIAN or LITTLE_ENDIAN
    
    Returns:
    
    This buffer
  - get
```
byte get()
```
    Relative get method. Reads the byte at this buffer's current position, and then increments the position.
    
    Returns:
    
    The byte at the buffer's current position
    
    Throws:
    
    BufferUnderflowException - If the buffer's current position is not smaller than its limit
  - get
```
byte get(int index)
```
    Absolute get method. Reads the byte at the given index.
    
    Parameters:
    
    index - The index from which the byte will be read
    
    Returns:
    
    The byte at the given index
    
    Throws:
    
    IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit
  - get
```
ByteBuf get(byte[] bytes)
```
    Relative bulk get method.
    
    This method transfers bytes 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:
    
    bytes - the destination byte array
    
    Returns:
    
    This buffer
    
    Throws:
    
    BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
  - get
```
ByteBuf get(int index,
            byte[] bytes)
```
    Absolute bulk get method.
    
    This method transfers bytes 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(index, a, 0, a.length)
 
```
    Parameters:
    
    index - The index from which the bytes will be read
    
    bytes - the destination byte array
    
    Returns:
    
    This buffer
    
    Throws:
    
    BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
  - get
```
ByteBuf get(byte[] bytes,
            int offset,
            int length)
```
    Relative bulk get method.
    This method transfers bytes from this buffer into the given destination array. If there are fewer bytes remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no bytes are transferred and a BufferUnderflowException is thrown.
    Otherwise, this method copies length bytes 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 bytes in this buffer and it is potentially much more efficient.
    Parameters:
    
    bytes - The array into which bytes are to be written
    
    offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length
    
    length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset
    
    Returns:
    
    This buffer
    
    Throws:
    
    BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
    
    IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold
  - get
```
ByteBuf get(int index,
            byte[] bytes,
            int offset,
            int length)
```
    Absolute bulk get method.
    This method transfers bytes from this buffer into the given destination array. If there are fewer bytes remaining in the buffer than are required to satisfy the request, that is, if length > remaining, then no bytes are transferred and a BufferUnderflowException is thrown.
    
    Otherwise, this method copies length bytes from this buffer into the given array, starting at the given index buffer and at the given offset in the array.
    
    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(i);
 
 
```
    except that it first checks that there are sufficient bytes in this buffer and it is potentially much more efficient.
    Parameters:
    
    index - The index from which the bytes will be read
    
    bytes - The array into which bytes are to be written
    
    offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length
    
    length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset
    
    Returns:
    
    This buffer
    
    Throws:
    
    BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
    
    IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold
  - getLong
```
long getLong()
```
    Relative get method for reading a long value.
    
    Reads the next eight bytes at this buffer's current position, composing them into a long value according to the current byte order, and then increments the position by eight.
    
    Returns:
    
    The long value at the buffer's current position
    
    Throws:
    
    BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer
  - getLong
```
long getLong(int index)
```
    Absolute get method for reading a long value.
    Reads eight bytes at the given index, composing them into a long value according to the current byte order.
    
    Parameters:
    
    index - The index from which the bytes will be read
    
    Returns:
    
    The long value at the given index
    
    Throws:
    
    IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven
  - getDouble
```
double getDouble()
```
    Relative get method for reading a double value.
    
    Reads the next eight bytes at this buffer's current position, composing them into a double value according to the current byte order, and then increments the position by eight.
    
    Returns:
    
    The double value at the buffer's current position
    
    Throws:
    
    BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer
  - getDouble
```
double getDouble(int index)
```
    Absolute get method for reading a double value.
    Reads eight bytes at the given index, composing them into a double value according to the current byte order.
    
    Parameters:
    
    index - The index from which the bytes will be read
    
    Returns:
    
    The double value at the given index
    
    Throws:
    
    IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven
  - getInt
```
int getInt()
```
    Relative get method for reading an int value.
    
    Reads the next four bytes at this buffer's current position, composing them into an int value according to the current byte order, and then increments the position by four.
    
    Returns:
    
    The int value at the buffer's current position
    
    Throws:
    
    BufferUnderflowException - If there are fewer than four bytes remaining in this buffer
  - getInt
```
int getInt(int index)
```
    Absolute get method for reading an int value.
    Reads four bytes at the given index, composing them into a int value according to the current byte order.
    
    Parameters:
    
    index - The index from which the bytes will be read
    
    Returns:
    
    The int value at the given index
    
    Throws:
    
    IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three
  - position
```
int position()
```
    Returns this buffer's position.
    
    Returns:
    
    The position of this buffer
  - limit
```
ByteBuf 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 - The new limit value; must be non-negative and no larger than this buffer's capacity
    
    Returns:
    
    This buffer
    
    Throws:
    
    IllegalArgumentException - If the preconditions on newLimit do not hold
  - asReadOnly
```
ByteBuf asReadOnly()
```
    Creates a new, read-only byte 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, and mark values will be identical to those of this buffer.
    
    Returns:
    
    The new, read-only byte buffer
  - duplicate
```
ByteBuf duplicate()
```
    Creates a new byte 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, and mark values 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:
    
    The new byte buffer
  - asNIO
```
ByteBuffer asNIO()
```
    Gets the underlying NIO ByteBuffer. Changes made directly to the returned buffer will be reflected in this instance, and vice versa, so be careful. This method should really only be used so that the underlying buffer can be passed directly to a socket channel.
    
    Returns:
    
    the underlying ByteBuffer
  - getReferenceCount
```
int getReferenceCount()
```
    Gets the current reference count, which starts at 0.
    
    Returns:
    
    the current count, which must be greater than or equal to 0
  - retain
```
ByteBuf retain()
```
    Retain an additional reference to this object. All retained references must be released, or there will be a leak.
    
    Returns:
    
    this
  - release
```
void release()
```
    Release a reference to this object.
    
    Throws:
    
    IllegalStateException - if the reference count is already 0

Interface ByteBuf

Method Summary

Method Detail

capacity

put

remaining

put

hasRemaining

put

flip

array

limit

position

clear

order

get

get

get

get

get

get

getLong

getLong

getDouble

getDouble

getInt

getInt

position

limit

asReadOnly

duplicate

asNIO

getReferenceCount

retain

release