org.simpleframework.common.buffer

Interface Buffer

All Known Implementing Classes:

ArrayBuffer, BufferAllocator

public interface Buffer

The Buffer interface represents a collection of bytes that can be written to and later read. This is used to provide a region of memory is such a way that the underlying representation of that memory is independent of its use. Typically buffers are implemented as either allocated byte arrays or files.

Author:

Niall Gallagher

See Also:

Allocator

Method Summary

Modifier and Type	Method and Description
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 len) 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 a buffer can be represented as a stream of bytes.

Method Detail

allocate

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.

Returns:

this returns a buffer which is a segment of this buffer

Throws:

IOException

open

InputStream open()
          throws IOException

This method is used so that a 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.

Returns:

a stream that can be used to read the buffered bytes

Throws:

IOException

encode

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.

Returns:

this returns a UTF-8 encoding of the buffer contents

Throws:

IOException

encode

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.

Parameters:

charset - this is the charset to encode the data with

Returns:

this returns the encoding of the buffer contents

Throws:

IOException

append

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.

Parameters:

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

Returns:

this returns this buffer for another operation

Throws:

IOException

append

Buffer append(byte[] array,
              int off,
              int len)
       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.

Parameters:

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

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

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

Returns:

this returns this buffer for another operation

Throws:

IOException

clear

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.

Throws:

IOException

close

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.

Throws:

IOException

length

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.

Returns:

this returns the number of bytes within the buffer