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public class: ChunkedInputStream [javadoc | source]

All Implemented Interfaces:

This class implements chunked transfer coding as described in the Section 3.6.1 of RFC 2616. It transparently coalesces chunks of a HTTP stream that uses chunked transfer coding.

3.6.1 Chunked Transfer Coding

The chunked encoding modifies the body of a message in order to transfer it as a series of chunks, each with its own size indicator, followed by an OPTIONAL trailer containing entity-header fields. This allows dynamically produced content to be transferred along with the information necessary for the recipient to verify that it has received the full message.

 Chunked-Body   = *chunk

 chunk          = chunk-size [ chunk-extension ] CRLF
                  chunk-data CRLF
 chunk-size     = 1*HEX
 last-chunk     = 1*("0") [ chunk-extension ] CRLF

 chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
 chunk-ext-name = token
 chunk-ext-val  = token | quoted-string
 chunk-data     = chunk-size(OCTET)
 trailer        = *(entity-header CRLF)

The chunk-size field is a string of hex digits indicating the size of the chunk. The chunked encoding is ended by any chunk whose size is zero, followed by the trailer, which is terminated by an empty line.

The trailer allows the sender to include additional HTTP header fields at the end of the message. The Trailer header field can be used to indicate which header fields are included in a trailer (see section 14.40).

A server using chunked transfer-coding in a response MUST NOT use the trailer for any header fields unless at least one of the following is true:

a)the request included a TE header field that indicates "trailers" is acceptable in the transfer-coding of the response, as described in section 14.39; or,

b)the server is the origin server for the response, the trailer fields consist entirely of optional metadata, and the recipient could use the message (in a manner acceptable to the origin server) without receiving this metadata. In other words, the origin server is willing to accept the possibility that the trailer fields might be silently discarded along the path to the client.

This requirement prevents an interoperability failure when the message is being received by an HTTP/1.1 (or later) proxy and forwarded to an HTTP/1.0 recipient. It avoids a situation where compliance with the protocol would have necessitated a possibly infinite buffer on the proxy.

Note that this class NEVER closes the underlying stream, even when close gets called. Instead, it will read until the "end" of its chunking on close, which allows for the seamless invocation of subsequent HTTP 1.1 calls, while not requiring the client to remember to read the entire contents of the response.

 public ChunkedInputStream(HttpDataReceiver in) 
Method from org.apache.http.io.ChunkedInputStream Summary:
close,   exhaustInputStream,   getFooters,   read,   read,   read
Methods from java.io.InputStream:
available,   close,   mark,   markSupported,   read,   read,   read,   reset,   skip
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.http.io.ChunkedInputStream Detail:
 public  void close() throws IOException 
    Upon close, this reads the remainder of the chunked message, leaving the underlying socket at a position to start reading the next response without scanning.
 static  void exhaustInputStream(InputStream inStream) throws IOException 
    Exhaust an input stream, reading until EOF has been encountered.

    Note that this function is intended as a non-public utility. This is a little weird, but it seemed silly to make a utility class for this one function, so instead it is just static and shared that way.

 public Header[] getFooters() 
 public int read() throws IOException 

    Returns all the data in a chunked stream in coalesced form. A chunk is followed by a CRLF. The method returns -1 as soon as a chunksize of 0 is detected.

    Trailer headers are read automcatically at the end of the stream and can be obtained with the getResponseFooters() method.

 public int read(byte[] b) throws IOException 
    Read some bytes from the stream.
 public int read(byte[] b,
    int off,
    int len) throws IOException 
    Read some bytes from the stream.