java.lang.Object
- org.jboss.netty.buffer.AbstractChannelBuffer
- - org.jboss.netty.buffer.HeapChannelBuffer
  - - org.jboss.netty.buffer.BigEndianHeapChannelBuffer
    - - org.jboss.netty.buffer.EmptyChannelBuffer

All Implemented Interfaces:

java.lang.Comparable<ChannelBuffer>, ChannelBuffer
```
public class EmptyChannelBuffer
extends BigEndianHeapChannelBuffer
```
An immutable empty buffer implementation. Typically used as a singleton via ChannelBuffers.EMPTY_BUFFER and returned by ChannelBuffers.buffer(int) etc when an empty buffer is requested.
Note: For backwards compatibility, this class extends BigEndianHeapChannelBuffer. However, it never makes any writes to the reader and writer indices, which avoids contention when the singleton instance is used concurrently.

Field Summary

Fields
Modifier and Type Field Description

private static byte[] BUFFER
- Fields inherited from class org.jboss.netty.buffer.HeapChannelBuffer
  array

Constructor Summary

Constructors
Constructor Description

EmptyChannelBuffer()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`checkReadableBytes(int length)`	Throws an `IndexOutOfBoundsException` the length is not 0.
`private void`	`checkWritableBytes(int length)`	Throws an `IndexOutOfBoundsException` the length is not 0.
`void`	`clear()`	Sets the `readerIndex` and `writerIndex` of this buffer to `0`.
`void`	`discardReadBytes()`	Discards the bytes between the 0th index and `readerIndex`.
`void`	`markReaderIndex()`	Marks the current `readerIndex` in this buffer.
`void`	`markWriterIndex()`	Marks the current `writerIndex` in this buffer.
`void`	`readBytes(byte[] dst)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` and increases the `readerIndex` by the number of the transferred bytes (= `dst.length`).
`void`	`readBytes(byte[] dst, int dstIndex, int length)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` and increases the `readerIndex` by the number of the transferred bytes (= `length`).
`ChannelBuffer`	`readBytes(int length)`	Transfers this buffer's data to a newly created buffer starting at the current `readerIndex` and increases the `readerIndex` by the number of the transferred bytes (= `length`).
`void`	`readBytes(java.io.OutputStream out, int length)`	Transfers this buffer's data to the specified stream starting at the current `readerIndex`.
`void`	`readBytes(java.nio.ByteBuffer dst)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` until the destination's position reaches its limit, and increases the `readerIndex` by the number of the transferred bytes.
`int`	`readBytes(java.nio.channels.GatheringByteChannel out, int length)`	Transfers this buffer's data to the specified stream starting at the current `readerIndex`.
`void`	`readBytes(ChannelBuffer dst)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` until the destination becomes non-writable, and increases the `readerIndex` by the number of the transferred bytes.
`void`	`readBytes(ChannelBuffer dst, int length)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` and increases the `readerIndex` by the number of the transferred bytes (= `length`).
`void`	`readBytes(ChannelBuffer dst, int dstIndex, int length)`	Transfers this buffer's data to the specified destination starting at the current `readerIndex` and increases the `readerIndex` by the number of the transferred bytes (= `length`).
`void`	`readerIndex(int readerIndex)`	Sets the `readerIndex` of this buffer.
`ChannelBuffer`	`readSlice(int length)`	Returns a new slice of this buffer's sub-region starting at the current `readerIndex` and increases the `readerIndex` by the size of the new slice (= `length`).
`void`	`resetReaderIndex()`	Repositions the current `readerIndex` to the marked `readerIndex` in this buffer.
`void`	`resetWriterIndex()`	Repositions the current `writerIndex` to the marked `writerIndex` in this buffer.
`void`	`setIndex(int readerIndex, int writerIndex)`	Sets the `readerIndex` and `writerIndex` of this buffer in one shot.
`void`	`skipBytes(int length)`	Increases the current `readerIndex` by the specified `length` in this buffer.
`void`	`writeBytes(byte[] src, int srcIndex, int length)`	Transfers the specified source array's data to this buffer starting at the current `writerIndex` and increases the `writerIndex` by the number of the transferred bytes (= `length`).
`int`	`writeBytes(java.io.InputStream in, int length)`	Transfers the content of the specified stream to this buffer starting at the current `writerIndex` and increases the `writerIndex` by the number of the transferred bytes.
`void`	`writeBytes(java.nio.ByteBuffer src)`	Transfers the specified source buffer's data to this buffer starting at the current `writerIndex` until the source buffer's position reaches its limit, and increases the `writerIndex` by the number of the transferred bytes.
`int`	`writeBytes(java.nio.channels.ScatteringByteChannel in, int length)`	Transfers the content of the specified channel to this buffer starting at the current `writerIndex` and increases the `writerIndex` by the number of the transferred bytes.
`void`	`writeBytes(ChannelBuffer src, int length)`	Transfers the specified source buffer's data to this buffer starting at the current `writerIndex` and increases the `writerIndex` by the number of the transferred bytes (= `length`).
`void`	`writeBytes(ChannelBuffer src, int srcIndex, int length)`	Transfers the specified source buffer's data to this buffer starting at the current `writerIndex` and increases the `writerIndex` by the number of the transferred bytes (= `length`).
`void`	`writerIndex(int writerIndex)`	Sets the `writerIndex` of this buffer.
`void`	`writeZero(int length)`	Fills this buffer with `NUL (0x00)` starting at the current `writerIndex` and increases the `writerIndex` by the specified `length`.

Methods inherited from class org.jboss.netty.buffer.BigEndianHeapChannelBuffer
copy, duplicate, factory, getInt, getLong, getShort, getUnsignedMedium, order, setInt, setLong, setMedium, setShort

Methods inherited from class org.jboss.netty.buffer.HeapChannelBuffer
array, arrayOffset, capacity, getByte, getBytes, getBytes, getBytes, getBytes, getBytes, hasArray, isDirect, setByte, setBytes, setBytes, setBytes, setBytes, setBytes, slice, toByteBuffer

Methods inherited from class org.jboss.netty.buffer.AbstractChannelBuffer
bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, compareTo, copy, ensureWritableBytes, equals, getBytes, getBytes, getBytes, getChar, getDouble, getFloat, getMedium, getUnsignedByte, getUnsignedInt, getUnsignedShort, hashCode, indexOf, indexOf, readable, readableBytes, readByte, readChar, readDouble, readerIndex, readFloat, readInt, readLong, readMedium, readShort, readUnsignedByte, readUnsignedInt, readUnsignedMedium, readUnsignedShort, setBytes, setBytes, setBytes, setChar, setDouble, setFloat, setZero, slice, toByteBuffer, toByteBuffers, toByteBuffers, toString, toString, toString, writable, writableBytes, writeByte, writeBytes, writeBytes, writeChar, writeDouble, writeFloat, writeInt, writeLong, writeMedium, writerIndex, writeShort

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - BUFFER
```
private static final byte[] BUFFER
```
- Constructor Detail
  - EmptyChannelBuffer
```
EmptyChannelBuffer()
```
- Method Detail
  - clear
```
public void clear()
```
    Description copied from interface: ChannelBuffer
    
    Sets the readerIndex and writerIndex of this buffer to 0. This method is identical to setIndex(0, 0).
    Please note that the behavior of this method is different from that of NIO buffer, which sets the limit to the capacity of the buffer.
    
    Specified by:
    
    clear in interface ChannelBuffer
    
    Overrides:
    
    clear in class AbstractChannelBuffer
  - readerIndex
```
public void readerIndex(int readerIndex)
```
    Description copied from interface: ChannelBuffer
    
    Sets the readerIndex of this buffer.
    
    Specified by:
    
    readerIndex in interface ChannelBuffer
    
    Overrides:
    
    readerIndex in class AbstractChannelBuffer
  - writerIndex
```
public void writerIndex(int writerIndex)
```
    Description copied from interface: ChannelBuffer
    
    Sets the writerIndex of this buffer.
    
    Specified by:
    
    writerIndex in interface ChannelBuffer
    
    Overrides:
    
    writerIndex in class AbstractChannelBuffer
  - setIndex
```
public void setIndex(int readerIndex,
                     int writerIndex)
```
    Description copied from interface: ChannelBuffer
    Sets the readerIndex and writerIndex of this buffer in one shot. This method is useful when you have to worry about the invocation order of ChannelBuffer.readerIndex(int) and ChannelBuffer.writerIndex(int) methods. For example, the following code will fail:
    // Create a buffer whose readerIndex, writerIndex and capacity are // 0, 0 and 8 respectively. ChannelBuffer buf = ChannelBuffers.buffer(8); // IndexOutOfBoundsException is thrown because the specified // readerIndex (2) cannot be greater than the current writerIndex (0). buf.readerIndex(2); buf.writerIndex(4);
    The following code will also fail:
    // Create a buffer whose readerIndex, writerIndex and capacity are // 0, 8 and 8 respectively. ChannelBuffer buf = ChannelBuffers.wrappedBuffer(new byte[8]); // readerIndex becomes 8. buf.readLong(); // IndexOutOfBoundsException is thrown because the specified // writerIndex (4) cannot be less than the current readerIndex (8). buf.writerIndex(4); buf.readerIndex(2);
    By contrast, this method guarantees that it never throws an IndexOutOfBoundsException as long as the specified indexes meet basic constraints, regardless what the current index values of the buffer are:
    // No matter what the current state of the buffer is, the following // call always succeeds as long as the capacity of the buffer is not // less than 4. buf.setIndex(2, 4);
    Specified by:
    
    setIndex in interface ChannelBuffer
    
    Overrides:
    
    setIndex in class AbstractChannelBuffer
  - markReaderIndex
```
public void markReaderIndex()
```
    Description copied from interface: ChannelBuffer
    
    Marks the current readerIndex in this buffer. You can reposition the current readerIndex to the marked readerIndex by calling ChannelBuffer.resetReaderIndex(). The initial value of the marked readerIndex is 0.
    
    Specified by:
    
    markReaderIndex in interface ChannelBuffer
    
    Overrides:
    
    markReaderIndex in class AbstractChannelBuffer
  - resetReaderIndex
```
public void resetReaderIndex()
```
    Description copied from interface: ChannelBuffer
    
    Repositions the current readerIndex to the marked readerIndex in this buffer.
    
    Specified by:
    
    resetReaderIndex in interface ChannelBuffer
    
    Overrides:
    
    resetReaderIndex in class AbstractChannelBuffer
  - markWriterIndex
```
public void markWriterIndex()
```
    Description copied from interface: ChannelBuffer
    
    Marks the current writerIndex in this buffer. You can reposition the current writerIndex to the marked writerIndex by calling ChannelBuffer.resetWriterIndex(). The initial value of the marked writerIndex is 0.
    
    Specified by:
    
    markWriterIndex in interface ChannelBuffer
    
    Overrides:
    
    markWriterIndex in class AbstractChannelBuffer
  - resetWriterIndex
```
public void resetWriterIndex()
```
    Description copied from interface: ChannelBuffer
    
    Repositions the current writerIndex to the marked writerIndex in this buffer.
    
    Specified by:
    
    resetWriterIndex in interface ChannelBuffer
    
    Overrides:
    
    resetWriterIndex 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
  - readBytes
```
public ChannelBuffer readBytes(int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to a newly created buffer starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). The returned buffer's readerIndex and writerIndex are 0 and length respectively.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
    
    Parameters:
    
    length - the number of bytes to transfer
    
    Returns:
    
    the newly created buffer which contains the transferred bytes
  - readSlice
```
public ChannelBuffer readSlice(int length)
```
    Description copied from interface: ChannelBuffer
    
    Returns a new slice of this buffer's sub-region starting at the current readerIndex and increases the readerIndex by the size of the new slice (= length).
    
    Specified by:
    
    readSlice in interface ChannelBuffer
    
    Overrides:
    
    readSlice in class AbstractChannelBuffer
    
    Parameters:
    
    length - the size of the new slice
    
    Returns:
    
    the newly created slice
  - readBytes
```
public void readBytes(byte[] dst,
                      int dstIndex,
                      int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
    
    dstIndex - the first index of the destination
    
    length - the number of bytes to transfer
  - readBytes
```
public void readBytes(byte[] dst)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= dst.length).
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
  - readBytes
```
public void readBytes(ChannelBuffer dst)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination becomes non-writable, and increases the readerIndex by the number of the transferred bytes. This method is basically same with ChannelBuffer.readBytes(ChannelBuffer, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes while ChannelBuffer.readBytes(ChannelBuffer, int, int) does not.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
  - readBytes
```
public void readBytes(ChannelBuffer dst,
                      int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). This method is basically same with ChannelBuffer.readBytes(ChannelBuffer, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes (= length) while ChannelBuffer.readBytes(ChannelBuffer, int, int) does not.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
  - readBytes
```
public void readBytes(ChannelBuffer dst,
                      int dstIndex,
                      int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
    
    dstIndex - the first index of the destination
    
    length - the number of bytes to transfer
  - readBytes
```
public void readBytes(java.nio.ByteBuffer dst)
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination's position reaches its limit, and increases the readerIndex by the number of the transferred bytes.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
  - readBytes
```
public int readBytes(java.nio.channels.GatheringByteChannel out,
                     int length)
              throws java.io.IOException
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified stream starting at the current readerIndex.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
    
    length - the maximum number of bytes to transfer
    
    Returns:
    
    the actual number of bytes written out to the specified channel
    
    Throws:
    
    java.io.IOException - if the specified channel threw an exception during I/O
  - readBytes
```
public void readBytes(java.io.OutputStream out,
                      int length)
               throws java.io.IOException
```
    Description copied from interface: ChannelBuffer
    
    Transfers this buffer's data to the specified stream starting at the current readerIndex.
    
    Specified by:
    
    readBytes in interface ChannelBuffer
    
    Overrides:
    
    readBytes in class AbstractChannelBuffer
    
    length - the number of bytes to transfer
    
    Throws:
    
    java.io.IOException - if the specified stream threw an exception during I/O
  - skipBytes
```
public void skipBytes(int length)
```
    Description copied from interface: ChannelBuffer
    
    Increases the current readerIndex by the specified length in this buffer.
    
    Specified by:
    
    skipBytes in interface ChannelBuffer
    
    Overrides:
    
    skipBytes in class AbstractChannelBuffer
  - writeBytes
```
public void writeBytes(byte[] src,
                       int srcIndex,
                       int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
    
    srcIndex - the first index of the source
    
    length - the number of bytes to transfer
  - writeBytes
```
public void writeBytes(ChannelBuffer src,
                       int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length). This method is basically same with ChannelBuffer.writeBytes(ChannelBuffer, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes (= length) while ChannelBuffer.writeBytes(ChannelBuffer, int, int) does not.
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
    
    length - the number of bytes to transfer
  - writeBytes
```
public void writeBytes(ChannelBuffer src,
                       int srcIndex,
                       int length)
```
    Description copied from interface: ChannelBuffer
    
    Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
    
    srcIndex - the first index of the source
    
    length - the number of bytes to transfer
  - writeBytes
```
public void writeBytes(java.nio.ByteBuffer src)
```
    Description copied from interface: ChannelBuffer
    
    Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer's position reaches its limit, and increases the writerIndex by the number of the transferred bytes.
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
  - writeBytes
```
public int writeBytes(java.io.InputStream in,
                      int length)
               throws java.io.IOException
```
    Description copied from interface: ChannelBuffer
    
    Transfers the content of the specified stream to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
    
    length - the number of bytes to transfer
    
    Returns:
    
    the actual number of bytes read in from the specified stream
    
    Throws:
    
    java.io.IOException - if the specified stream threw an exception during I/O
  - writeBytes
```
public int writeBytes(java.nio.channels.ScatteringByteChannel in,
                      int length)
               throws java.io.IOException
```
    Description copied from interface: ChannelBuffer
    
    Transfers the content of the specified channel to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
    
    Specified by:
    
    writeBytes in interface ChannelBuffer
    
    Overrides:
    
    writeBytes in class AbstractChannelBuffer
    
    length - the maximum number of bytes to transfer
    
    Returns:
    
    the actual number of bytes read in from the specified channel
    
    Throws:
    
    java.io.IOException - if the specified channel threw an exception during I/O
  - writeZero
```
public void writeZero(int length)
```
    Description copied from interface: ChannelBuffer
    
    Fills this buffer with NUL (0x00) starting at the current writerIndex and increases the writerIndex by the specified length.
    
    Specified by:
    
    writeZero in interface ChannelBuffer
    
    Overrides:
    
    writeZero in class AbstractChannelBuffer
    
    Parameters:
    
    length - the number of NULs to write to the buffer
  - checkWritableBytes
```
private void checkWritableBytes(int length)
```
    Throws an IndexOutOfBoundsException the length is not 0.
  - checkReadableBytes
```
protected void checkReadableBytes(int length)
```
    Throws an IndexOutOfBoundsException the length is not 0.
    
    Overrides:
    
    checkReadableBytes in class AbstractChannelBuffer

Class EmptyChannelBuffer

Field Summary

Fields inherited from class org.jboss.netty.buffer.HeapChannelBuffer

Constructor Summary

Method Summary

Methods inherited from class org.jboss.netty.buffer.BigEndianHeapChannelBuffer

Methods inherited from class org.jboss.netty.buffer.HeapChannelBuffer

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

Methods inherited from class java.lang.Object

Field Detail

BUFFER

Constructor Detail

EmptyChannelBuffer

Method Detail

clear

readerIndex

writerIndex

setIndex

markReaderIndex

resetReaderIndex

markWriterIndex

resetWriterIndex

discardReadBytes

readBytes

readSlice

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

skipBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeZero

checkWritableBytes

checkReadableBytes