org.jboss.netty.buffer

## Class CompositeChannelBuffer

- java.lang.Object
- - org.jboss.netty.buffer.AbstractChannelBuffer
  - - org.jboss.netty.buffer.CompositeChannelBuffer

All Implemented Interfaces:
  Comparable<ChannelBuffer>, ChannelBuffer

    public class CompositeChannelBuffer
    extends AbstractChannelBuffer

A virtual buffer which shows multiple buffers as a single merged buffer. It is recommended to use `ChannelBuffers.wrappedBuffer(ChannelBuffer...)` instead of calling the constructor explicitly.

### Constructor Summary

Constructors
Constructor and Description
`CompositeChannelBuffer(ByteOrder endianness, List<ChannelBuffer> buffers, boolean gathering)`

### Method Summary

Methods
`byte[]` `array()` Returns the backing byte array of this buffer.
`int` `arrayOffset()` Returns the offset of the first byte within the backing byte array of this buffer.
`int` `capacity()` Returns the number of bytes (octets) this buffer can contain.
`ChannelBuffer` `copy(int index, int length)` Returns a copy of this buffer's sub-region.
`List<ChannelBuffer>` `decompose(int index, int length)` Same with `slice(int, int)` except that this method returns a list.
`void` `discardReadBytes()` Discards the bytes between the 0th index and `readerIndex`.
`ChannelBuffer` `duplicate()` Returns a buffer which shares the whole region of this buffer.
`ChannelBufferFactory` `factory()` Returns the factory which creates a `ChannelBuffer` whose type and default `ByteOrder` are same with this buffer.
`ChannelBuffer` `getBuffer(int index)` Returns the `ChannelBuffer` portion of this `CompositeChannelBuffer` that contains the specified `index`.
`byte` `getByte(int index)` Gets a byte at the specified absolute `index` in this buffer.
`void` `getBytes(int index, byte[] dst, int dstIndex, int length)` Transfers this buffer's data to the specified destination starting at the specified absolute `index`.
`void` `getBytes(int index, ByteBuffer dst)` Transfers this buffer's data to the specified destination starting at the specified absolute `index` until the destination's position reaches its limit.
`void` `getBytes(int index, ChannelBuffer dst, int dstIndex, int length)` Transfers this buffer's data to the specified destination starting at the specified absolute `index`.
`int` `getBytes(int index, GatheringByteChannel out, int length)` Transfers this buffer's data to the specified channel starting at the specified absolute `index`.
`void` `getBytes(int index, OutputStream out, int length)` Transfers this buffer's data to the specified stream starting at the specified absolute `index`.
`int` `getInt(int index)` Gets a 32-bit integer at the specified absolute `index` in this buffer.
`long` `getLong(int index)` Gets a 64-bit long integer at the specified absolute `index` in this buffer.
`short` `getShort(int index)` Gets a 16-bit short integer at the specified absolute `index` in this buffer.
`int` `getUnsignedMedium(int index)` Gets an unsigned 24-bit medium integer at the specified absolute `index` in this buffer.
`boolean` `hasArray()` Returns `true` if and only if this buffer has a backing byte array.
`boolean` `isDirect()` Returns `true` if and only if this buffer is backed by an NIO direct buffer.
`int` `numComponents()`
`ByteOrder` `order()` Returns the endianness of this buffer.
`void` `setByte(int index, int value)` Sets the specified byte at the specified absolute `index` in this buffer.
`void` `setBytes(int index, byte[] src, int srcIndex, int length)` Transfers the specified source array's data to this buffer starting at the specified absolute `index`.
`void` `setBytes(int index, ByteBuffer src)` Transfers the specified source buffer's data to this buffer starting at the specified absolute `index` until the source buffer's position reaches its limit.
`void` `setBytes(int index, ChannelBuffer src, int srcIndex, int length)` Transfers the specified source buffer's data to this buffer starting at the specified absolute `index`.
`int` `setBytes(int index, InputStream in, int length)` Transfers the content of the specified source stream to this buffer starting at the specified absolute `index`.
`int` `setBytes(int index, ScatteringByteChannel in, int length)` Transfers the content of the specified source channel to this buffer starting at the specified absolute `index`.
`void` `setInt(int index, int value)` Sets the specified 32-bit integer at the specified absolute `index` in this buffer.
`void` `setLong(int index, long value)` Sets the specified 64-bit long integer at the specified absolute `index` in this buffer.
`void` `setMedium(int index, int value)` Sets the specified 24-bit medium integer at the specified absolute `index` in this buffer.
`void` `setShort(int index, int value)` Sets the specified 16-bit short integer at the specified absolute `index` in this buffer.
`ChannelBuffer` `slice(int index, int length)` Returns a slice of this buffer's sub-region.
`ByteBuffer` `toByteBuffer(int index, int length)` Converts this buffer's sub-region into a NIO buffer.
`ByteBuffer[]` `toByteBuffers(int index, int length)` Converts this buffer's sub-region into an array of NIO buffers.
`String` `toString()` Returns the string representation of this buffer.
`boolean` `useGathering()` Return `true` if gathering writes / reads should be used for this `CompositeChannelBuffer`

### Methods inherited from class org.jboss.netty.buffer.AbstractChannelBuffer

`bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, checkReadableBytes, clear, compareTo, copy, ensureWritableBytes, equals, getBytes, getBytes, getBytes, getChar, getDouble, getFloat, getMedium, getUnsignedByte, getUnsignedInt, getUnsignedShort, hashCode, indexOf, indexOf, markReaderIndex, markWriterIndex, readable, readableBytes, readByte, readBytes, readBytes, readBytes, readBytes, readBytes, readBytes, readBytes, readBytes, readBytes, readBytes, readChar, readDouble, readerIndex, readerIndex, readFloat, readInt, readLong, readMedium, readShort, readSlice, readSlice, readUnsignedByte, readUnsignedInt, readUnsignedMedium, readUnsignedShort, resetReaderIndex, resetWriterIndex, setBytes, setBytes, setBytes, setChar, setDouble, setFloat, setIndex, setZero, skipBytes, skipBytes, slice, toByteBuffer, toByteBuffers, toString, toString, toString, toString, toString, toString, writable, writableBytes, writeByte, writeBytes, writeBytes, writeBytes, writeBytes, writeBytes, writeBytes, writeBytes, writeBytes, writeChar, writeDouble, writeFloat, writeInt, writeLong, writeMedium, writerIndex, writerIndex, writeShort, writeZero`

### Methods inherited from class java.lang.Object

`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

### Constructor Detail

#### CompositeChannelBuffer

    public CompositeChannelBuffer(ByteOrder endianness,
                          List<ChannelBuffer> buffers,
                          boolean gathering)

### Method Detail

#### useGathering

    public boolean useGathering()

Return `true` if gathering writes / reads should be used for this `CompositeChannelBuffer`

#### decompose

    public List<ChannelBuffer> decompose(int index,
                                int length)

Same with `slice(int, int)` except that this method returns a list.

#### factory

    public ChannelBufferFactory factory()

Description copied from interface: `ChannelBuffer`
Returns the factory which creates a `ChannelBuffer` whose type and default `ByteOrder` are same with this buffer.

#### order

    public ByteOrder order()

Description copied from interface: `ChannelBuffer`
Returns the endianness of this buffer.

#### isDirect

    public boolean isDirect()

Description copied from interface: `ChannelBuffer`
Returns `true` if and only if this buffer is backed by an NIO direct buffer.

#### hasArray

    public boolean hasArray()

Description copied from interface: `ChannelBuffer`
Returns `true` if and only if this buffer has a backing byte array. If this method returns true, you can safely call `ChannelBuffer.array()` and `ChannelBuffer.arrayOffset()`.

#### array

    public byte[] array()

Description copied from interface: `ChannelBuffer`
Returns the backing byte array of this buffer.

#### arrayOffset

    public int arrayOffset()

Description copied from interface: `ChannelBuffer`
Returns the offset of the first byte within the backing byte array of this buffer.

#### capacity

    public int capacity()

Description copied from interface: `ChannelBuffer`
Returns the number of bytes (octets) this buffer can contain.

#### numComponents

    public int numComponents()

#### getByte

    public byte getByte(int index)

Description copied from interface: `ChannelBuffer`
Gets a byte at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getShort

    public short getShort(int index)

Description copied from interface: `ChannelBuffer`
Gets a 16-bit short integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getUnsignedMedium

    public int getUnsignedMedium(int index)

Description copied from interface: `ChannelBuffer`
Gets an unsigned 24-bit medium integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getInt

    public int getInt(int index)

Description copied from interface: `ChannelBuffer`
Gets a 32-bit integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getLong

    public long getLong(int index)

Description copied from interface: `ChannelBuffer`
Gets a 64-bit long integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getBytes

    public void getBytes(int index,
                byte[] dst,
                int dstIndex,
                int length)

Description copied from interface: `ChannelBuffer`
Transfers this buffer's data to the specified destination starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

  `dstIndex` - the first index of the destination
  `length` - the number of bytes to transfer

#### getBytes

    public void getBytes(int index,
                ByteBuffer dst)

Description copied from interface: `ChannelBuffer`
Transfers this buffer's data to the specified destination starting at the specified absolute `index` until the destination's position reaches its limit. This method does not modify `readerIndex` or `writerIndex` of this buffer while the destination's `position` will be increased.

#### getBytes

    public void getBytes(int index,
                ChannelBuffer dst,
                int dstIndex,
                int length)

Description copied from interface: `ChannelBuffer`
Transfers this buffer's data to the specified destination starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of both the source (i.e. `this`) and the destination.

  `dstIndex` - the first index of the destination
  `length` - the number of bytes to transfer

#### getBytes

    public int getBytes(int index,
               GatheringByteChannel out,
               int length)
                 throws IOException

Description copied from interface: `ChannelBuffer`
Transfers this buffer's data to the specified channel starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

  `length` - the maximum number of bytes to transfer
Returns:
  the actual number of bytes written out to the specified channel
Throws:
  `IOException` - if the specified channel threw an exception during I/O

#### getBytes

    public void getBytes(int index,
                OutputStream out,
                int length)
                  throws IOException

Description copied from interface: `ChannelBuffer`
Transfers this buffer's data to the specified stream starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

  `length` - the number of bytes to transfer
Throws:
  `IOException` - if the specified stream threw an exception during I/O

#### setByte

    public void setByte(int index,
               int value)

Description copied from interface: `ChannelBuffer`
Sets the specified byte at the specified absolute `index` in this buffer. The 24 high-order bits of the specified value are ignored. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setShort

    public void setShort(int index,
                int value)

Description copied from interface: `ChannelBuffer`
Sets the specified 16-bit short integer at the specified absolute `index` in this buffer. The 16 high-order bits of the specified value are ignored. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setMedium

    public void setMedium(int index,
                 int value)

Description copied from interface: `ChannelBuffer`
Sets the specified 24-bit medium integer at the specified absolute `index` in this buffer. Please note that the most significant byte is ignored in the specified value. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setInt

    public void setInt(int index,
              int value)

Description copied from interface: `ChannelBuffer`
Sets the specified 32-bit integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setLong

    public void setLong(int index,
               long value)

Description copied from interface: `ChannelBuffer`
Sets the specified 64-bit long integer at the specified absolute `index` in this buffer. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setBytes

    public void setBytes(int index,
                byte[] src,
                int srcIndex,
                int length)

Description copied from interface: `ChannelBuffer`
Transfers the specified source array's data to this buffer starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setBytes

    public void setBytes(int index,
                ByteBuffer src)

Description copied from interface: `ChannelBuffer`
Transfers the specified source buffer's data to this buffer starting at the specified absolute `index` until the source buffer's position reaches its limit. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### setBytes

    public void setBytes(int index,
                ChannelBuffer src,
                int srcIndex,
                int length)

Description copied from interface: `ChannelBuffer`
Transfers the specified source buffer's data to this buffer starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of both the source (i.e. `this`) and the destination.

  `srcIndex` - the first index of the source
  `length` - the number of bytes to transfer

#### setBytes

    public int setBytes(int index,
               InputStream in,
               int length)
                 throws IOException

Description copied from interface: `ChannelBuffer`
Transfers the content of the specified source stream to this buffer starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

  `length` - the number of bytes to transfer
Returns:
  the actual number of bytes read in from the specified channel. `-1` if the specified channel is closed.
Throws:
  `IOException` - if the specified stream threw an exception during I/O

#### setBytes

    public int setBytes(int index,
               ScatteringByteChannel in,
               int length)
                 throws IOException

Description copied from interface: `ChannelBuffer`
Transfers the content of the specified source channel to this buffer starting at the specified absolute `index`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

  `length` - the maximum number of bytes to transfer
Returns:
  the actual number of bytes read in from the specified channel. `-1` if the specified channel is closed.
Throws:
  `IOException` - if the specified channel threw an exception during I/O

#### duplicate

    public ChannelBuffer duplicate()

Description copied from interface: `ChannelBuffer`
Returns a buffer which shares the whole region of this buffer. Modifying the content of the returned buffer or this buffer affects each other's content while they maintain separate indexes and marks. This method is identical to `buf.slice(0, buf.capacity())`. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### copy

    public ChannelBuffer copy(int index,
                     int length)

Description copied from interface: `ChannelBuffer`
Returns a copy of this buffer's sub-region. Modifying the content of the returned buffer or this buffer does not affect each other at all. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### getBuffer

    public ChannelBuffer getBuffer(int index)
                            throws IndexOutOfBoundsException

Returns the `ChannelBuffer` portion of this `CompositeChannelBuffer` that contains the specified `index`. This is an expert method!

Please note that since a `CompositeChannelBuffer` is made up of multiple `ChannelBuffer`s, this does not return the full buffer. Instead, it only returns a portion of the composite buffer where the index is located

Parameters:
  `index` - The `index` to search for and include in the returned `ChannelBuffer`
Returns:
  The `ChannelBuffer` that contains the specified `index`
Throws:
  `IndexOutOfBoundsException` - when the specified `index` is less than zero, or larger than `capacity()`

#### slice

    public ChannelBuffer slice(int index,
                      int length)

Description copied from interface: `ChannelBuffer`
Returns a slice of this buffer's sub-region. Modifying the content of the returned buffer or this buffer affects each other's content while they maintain separate indexes and marks. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### toByteBuffer

    public ByteBuffer toByteBuffer(int index,
                          int length)

Description copied from interface: `ChannelBuffer`
Converts this buffer's sub-region into a NIO buffer. The returned buffer might or might not share the content with this buffer, while they have separate indexes and marks. This method does not modify `readerIndex` or `writerIndex` of this buffer.

#### toByteBuffers

    public ByteBuffer[] toByteBuffers(int index,
                             int length)

Description copied from interface: `ChannelBuffer`
Converts this buffer's sub-region into an array of NIO buffers. The returned buffers might or might not share the content with this buffer, while they have separate indexes and marks. This method does not modify `readerIndex` or `writerIndex` of this buffer.

Specified by:
  `toByteBuffers` in interface `ChannelBuffer`
Overrides:
  `toByteBuffers` in class `AbstractChannelBuffer`

#### discardReadBytes

    public void discardReadBytes()

Description copied from interface: `ChannelBuffer`
Discards the bytes between the 0th index and `readerIndex`. It moves the bytes between `readerIndex` and `writerIndex` to the 0th index, and sets `readerIndex` and `writerIndex` to `0` and `oldWriterIndex - oldReaderIndex` respectively.

Please refer to the class documentation for more detailed explanation.

Specified by:
  `discardReadBytes` in interface `ChannelBuffer`
Overrides:
  `discardReadBytes` in class `AbstractChannelBuffer`

#### toString

    public String toString()

Description copied from interface: `ChannelBuffer`
Returns the string representation of this buffer. This method does not necessarily return the whole content of the buffer but returns the values of the key properties such as `ChannelBuffer.readerIndex()`, `ChannelBuffer.writerIndex()` and `ChannelBuffer.capacity()`.

Specified by:
  `toString` in interface `ChannelBuffer`
Overrides:
  `toString` in class `AbstractChannelBuffer`