org.simpleframework.util.buffer
Class ArrayBuffer

java.lang.Object
  org.simpleframework.util.buffer.ArrayBuffer

All Implemented Interfaces:

Buffer

public class ArrayBuffer
extends Object
implements Buffer

The ArrayBuffer is intended to be a general purpose byte buffer that stores bytes in an single internal byte array. The intended use of this buffer is to provide a simple buffer object to read and write bytes with. In particular this provides a high performance buffer that can be used to read and write bytes fast.

This provides several convenience methods which make the use of the buffer easy and useful. This buffer allows an initial capacity to be specified however if there is a need for extra space to be added to buffer then the append methods will expand the capacity of the buffer as needed.

Author:

Niall Gallagher

See Also:

ArrayAllocator

Constructor Summary

ArrayBuffer()
Constructor for the ArrayBuffer object.

ArrayBuffer(int size)
Constructor for the ArrayBuffer object.

ArrayBuffer(int size, int limit)
Constructor for the ArrayBuffer object.

Method Summary

Buffer	allocate() This method is used to allocate a segment of this buffer as a separate buffer object.
Buffer	append(byte[] array) This method is used to append bytes to the end of the buffer.
Buffer	append(byte[] array, int off, int size) This method is used to append bytes to the end of the buffer.
void	clear() This will clear all data from the buffer.
void	close() This method is used to ensure the buffer can be closed.
String	encode() This method is used to acquire the buffered bytes as a string.
String	encode(String charset) This method is used to acquire the buffered bytes as a string.
long	length() This is used to provide the number of bytes that have been written to the buffer.
InputStream	open() This method is used so that the buffer can be represented as a stream of bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayBuffer

public ArrayBuffer()

Constructor for the ArrayBuffer object. The initial capacity of the default buffer object is set to 16, the capacity will be expanded when the append methods are used and there is not enough space to accommodate the extra bytes.

ArrayBuffer

public ArrayBuffer(int size)

Constructor for the ArrayBuffer object. The initial capacity of the buffer object is set to given size, the capacity will be expanded when the append methods are used and there is not enough space to accommodate the extra bytes.

Parameters:

size - the initial capacity of this buffer instance

ArrayBuffer

public ArrayBuffer(int size,
                   int limit)

Constructor for the ArrayBuffer object. The initial capacity of the buffer object is set to given size, the capacity will be expanded when the append methods are used and there is not enough space to accommodate the extra bytes.

Parameters:

size - the initial capacity of this buffer instance

limit - this is the maximum allowable buffer capacity

Method Detail

open

public InputStream open()

This method is used so that the buffer can be represented as a stream of bytes. This provides a quick means to access the data that has been written to the buffer. It wraps the buffer within an input stream so that it can be read directly.

Specified by:

open in interface Buffer

Returns:

a stream that can be used to read the buffered bytes

allocate

public Buffer allocate()
                throws IOException

This method is used to allocate a segment of this buffer as a separate buffer object. This allows the buffer to be sliced in to several smaller independent buffers, while still allowing the parent buffer to manage a single buffer. This is useful if the parent is split in to logically smaller segments.

Specified by:

allocate in interface Buffer

Returns:

this returns a buffer which is a segment of this buffer

Throws:

IOException

encode

public String encode()
              throws IOException

This method is used to acquire the buffered bytes as a string. This is useful if the contents need to be manipulated as a string or transferred into another encoding. If the UTF-8 content encoding is not supported the platform default is used, however this is unlikely as UTF-8 should be supported.

Specified by:

encode in interface Buffer

Returns:

this returns a UTF-8 encoding of the buffer contents

Throws:

IOException

encode

public String encode(String charset)
              throws IOException

This method is used to acquire the buffered bytes as a string. This is useful if the contents need to be manipulated as a string or transferred into another encoding. This will convert the bytes using the specified character encoding format.

Specified by:

encode in interface Buffer

Parameters:

charset - this is the charset to encode the data with

Returns:

this returns the encoding of the buffer contents

Throws:

IOException

append

public Buffer append(byte[] array)
              throws IOException

This method is used to append bytes to the end of the buffer. This will expand the capacity of the buffer if there is not enough space to accommodate the extra bytes.

Specified by:

append in interface Buffer

Parameters:

array - this is the byte array to append to this buffer

Returns:

this returns this buffer for another operation

Throws:

IOException

append

public Buffer append(byte[] array,
                     int off,
                     int size)
              throws IOException

This method is used to append bytes to the end of the buffer. This will expand the capacity of the buffer if there is not enough space to accommodate the extra bytes.

Specified by:

append in interface Buffer

Parameters:

array - this is the byte array to append to this buffer

off - this is the offset to begin reading the bytes from

size - the number of bytes to be read from the array

Returns:

this returns this buffer for another operation

Throws:

IOException

clear

public void clear()
           throws IOException

This will clear all data from the buffer. This simply sets the count to be zero, it will not clear the memory occupied by the instance as the internal buffer will remain. This allows the memory occupied to be reused as many times as is required.

Specified by:

clear in interface Buffer

Throws:

IOException

close

public void close()
           throws IOException

This method is used to ensure the buffer can be closed. Once the buffer is closed it is an immutable collection of bytes and can not longer be modified. This ensures that it can be passed by value without the risk of modification of the bytes.

Specified by:

close in interface Buffer

Throws:

IOException

length

public long length()

This is used to provide the number of bytes that have been written to the buffer. This increases as bytes are appended to the buffer. if the buffer is cleared this resets to zero.

Specified by:

length in interface Buffer

Returns:

this returns the number of bytes within the buffer