Class ChunkedConsumer

java.lang.Object
org.simpleframework.http.message.UpdateConsumer
org.simpleframework.http.message.ChunkedConsumer
All Implemented Interfaces:
BodyConsumer, ByteConsumer

public class ChunkedConsumer extends UpdateConsumer
The ChunkedConsumer is reads an decodes a stream using the chunked transfer coding. This is used so that any data sent in the chunked transfer coding can be decoded. All bytes are appended to an internal buffer so that they can be read without having to parse the encoding.

    length := 0
    read chunk-size, chunk-extension (if any) and CRLF
    while (chunk-size > 0) {
       read chunk-data and CRLF
       append chunk-data to entity-body
       length := length + chunk-size
       read chunk-size and CRLF
    }
    read entity-header
    while (entity-header not empty) {
       append entity-header to existing header fields
       read entity-header
    }

 
The above algorithm is taken from RFC 2616 section 19.4.6. This coding scheme is used in HTTP pipelines so that dynamic content, that is, content with which a length cannot be determined does not require a connection close to delimit the message body.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private Allocator
    This is used to create the internal buffer for the body.
    private Buffer
    This is the internal buffer used to capture the body read.
    private int
    This is the number of bytes left in the current chunk.
    private int
    This is the number of bytes appended to the line buffer.
    private boolean
    This is used to determine if the zero length chunk was read.
    private byte[]
    This is used to accumulate the bytes of the chunk size line.
    private boolean
    This is used to determine whether a full chunk has been read.

    Fields inherited from class org.simpleframework.http.message.UpdateConsumer

    array, finished
  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
     
    Constructor for the ChunkedConsumer object.
    private
    ChunkedConsumer(Allocator allocator, int chunk)
    Constructor for the ChunkedConsumer object.
  • Method Summary

    Modifier and Type
    Method
    Description
    private void
    append(byte[] array, int off, int len)
    This method is used to append the contents of the array to the internal buffer.
    This is used to acquire the body that has been consumed.
    private void
    This method is used to convert the size in hexidecimal to a decimal int.
    private int
    toDecimal(byte octet)
    This performs a conversion from a character to an integer.
    protected int
    update(byte[] array, int off, int size)
    This is used to process the bytes that have been read from the cursor.

    Methods inherited from class org.simpleframework.http.message.UpdateConsumer

    commit, consume, isFinished

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • allocator

      private Allocator allocator
      This is used to create the internal buffer for the body.
    • buffer

      private Buffer buffer
      This is the internal buffer used to capture the body read.
    • terminal

      private boolean terminal
      This is used to determine whether a full chunk has been read.
    • last

      private boolean last
      This is used to determine if the zero length chunk was read.
    • line

      private byte[] line
      This is used to accumulate the bytes of the chunk size line.
    • count

      private int count
      This is the number of bytes appended to the line buffer.
    • chunk

      private int chunk
      This is the number of bytes left in the current chunk.
  • Constructor Details

    • ChunkedConsumer

      public ChunkedConsumer(Allocator allocator)
      Constructor for the ChunkedConsumer object. This is used to create a consumer that reads chunked encoded data and appended that data in decoded form to an internal buffer so that it can be read in a clean decoded fromat.
      Parameters:
      allocator - this is used to allocate the internal buffer
    • ChunkedConsumer

      private ChunkedConsumer(Allocator allocator, int chunk)
      Constructor for the ChunkedConsumer object. This is used to create a consumer that reads chunked encoded data and appended that data in decoded form to an internal buffer so that it can be read in a clean decoded fromat.
      Parameters:
      allocator - this is used to allocate the internal buffer
      chunk - this is the maximum size line allowed
  • Method Details

    • getBody

      public Body getBody()
      This is used to acquire the body that has been consumed. This will return a body which can be used to read the content of the message, also if the request is multipart upload then all of the parts are provided as Attachment objects. Each part can then be read as an individual message.
      Returns:
      the body that has been consumed by this instance
    • append

      private void append(byte[] array, int off, int len) throws IOException
      This method is used to append the contents of the array to the internal buffer. The appended bytes can be acquired from the internal buffer using an InputStream, or the text of the appended bytes can be acquired by encoding the bytes.
      Parameters:
      array - this is the array of bytes to be appended
      off - this is the start offset in the array to read from
      len - this is the number of bytes to write to the buffer
      Throws:
      IOException
    • update

      protected int update(byte[] array, int off, int size) throws IOException
      This is used to process the bytes that have been read from the cursor. This will keep reading bytes from the stream until such time as the zero length chunk has been read from the stream. If the zero length chunk is encountered then the overflow count is returned so it can be used to reset the cursor.
      Specified by:
      update in class UpdateConsumer
      Parameters:
      array - this is a chunk read from the cursor
      off - this is the offset within the array the chunk starts
      size - this is the number of bytes within the array
      Returns:
      this returns the number of bytes overflow that is read
      Throws:
      IOException
    • parse

      private void parse() throws IOException
      This method is used to convert the size in hexidecimal to a decimal int. This will use the specified number of bytes from the internal buffer and parse each character read as a hexidecimal character. This stops interpreting the size line when a non-hexidecimal character is encountered.
      Throws:
      IOException
    • toDecimal

      private int toDecimal(byte octet)
      This performs a conversion from a character to an integer. If the character given, as a byte, is a hexidecimal char this will convert it into its integer equivelant. So a char of A is converted into 10.
      Parameters:
      octet - this is an ISO 8869-1 hexidecimal character
      Returns:
      returns the hex character into its decinal value