|
|||||||||
| Home >> All >> org >> apache >> http >> [ io overview ] | PREV CLASS NEXT CLASS | ||||||||
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||
org.apache.http.io
Class ChunkedInputStream
java.lang.Objectjava.io.InputStream
- All Implemented Interfaces:
- java.io.Closeable
- public class ChunkedInputStream
- extends java.io.InputStream
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.
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
last-chunk
trailer
CRLF
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.
- Since:
- 2.0
| Field Summary | |
private boolean |
bof
True if we'are at the beginning of stream |
private CharArrayBuffer |
buffer
|
private int |
chunkSize
The chunk size |
private boolean |
closed
True if this stream is closed |
private boolean |
eof
True if we've reached the end of stream |
private org.apache.http.Header[] |
footers
|
private HttpDataReceiver |
in
The data receiver that we're wrapping |
private int |
pos
The current position within the current chunk |
| Constructor Summary | |
ChunkedInputStream(HttpDataReceiver in)
|
|
| Method Summary | |
void |
close()
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. |
(package private) static void |
exhaustInputStream(java.io.InputStream inStream)
Exhaust an input stream, reading until EOF has been encountered. |
private int |
getChunkSize()
Expects the stream to start with a chunksize in hex with optional comments after a semicolon. |
org.apache.http.Header[] |
getFooters()
|
private void |
nextChunk()
Read the next chunk. |
private void |
parseTrailerHeaders()
Reads and stores the Trailer headers. |
int |
read()
Returns all the data in a chunked stream in coalesced form. |
int |
read(byte[] b)
Read some bytes from the stream. |
int |
read(byte[] b,
int off,
int len)
Read some bytes from the stream. |
| Methods inherited from class java.io.InputStream |
available, mark, markSupported, reset, skip |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
in
private HttpDataReceiver in
- The data receiver that we're wrapping
buffer
private final CharArrayBuffer buffer
chunkSize
private int chunkSize
- The chunk size
pos
private int pos
- The current position within the current chunk
bof
private boolean bof
- True if we'are at the beginning of stream
eof
private boolean eof
- True if we've reached the end of stream
closed
private boolean closed
- True if this stream is closed
footers
private org.apache.http.Header[] footers
| Constructor Detail |
ChunkedInputStream
public ChunkedInputStream(HttpDataReceiver in)
| Method Detail |
read
public int read()
throws java.io.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.
read
public int read(byte[] b,
int off,
int len)
throws java.io.IOException
- Read some bytes from the stream.
read
public int read(byte[] b)
throws java.io.IOException
- Read some bytes from the stream.
nextChunk
private void nextChunk()
throws java.io.IOException
- Read the next chunk.
getChunkSize
private int getChunkSize()
throws java.io.IOException
- Expects the stream to start with a chunksize in hex with optional
comments after a semicolon. The line must end with a CRLF: "a3; some
comment\r\n" Positions the stream at the start of the next line.
parseTrailerHeaders
private void parseTrailerHeaders()
throws java.io.IOException
- Reads and stores the Trailer headers.
close
public void close()
throws java.io.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.
getFooters
public org.apache.http.Header[] getFooters()
exhaustInputStream
static void exhaustInputStream(java.io.InputStream inStream) throws java.io.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.
|
|||||||||
| Home >> All >> org >> apache >> http >> [ io overview ] | PREV CLASS NEXT CLASS | ||||||||
|
SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||