Package io.netty.handler.codec.http

Class HttpObjectEncoder<H extends HttpMessage>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<Object>

io.netty.handler.codec.http.HttpObjectEncoder<H>

All Implemented Interfaces:

ChannelHandler, ChannelOutboundHandler

Direct Known Subclasses:

HttpRequestEncoder, HttpResponseEncoder, RtspEncoder, RtspObjectEncoder

public abstract class HttpObjectEncoder<H extends HttpMessage>
extends MessageToMessageEncoder<Object>

Encodes an HttpMessage or an HttpContent into a ByteBuf.

Extensibility

Please note that this encoder is designed to be extended to implement a protocol derived from HTTP, such as RTSP and ICAP. To implement the encoder of such a derived protocol, extend this class and implement all abstract methods properly.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	COPY_CONTENT_THRESHOLD
private static final ByteBuf	CRLF_BUF
(package private) static final int	CRLF_SHORT
private static final float	HEADERS_WEIGHT_HISTORICAL
private static final float	HEADERS_WEIGHT_NEW
private float	headersEncodedSizeAccumulator	Used to calculate an exponential moving average of the encoded size of the initial line and the headers for a guess for future buffer allocations.
private final List<Object>	out
private static final int	ST_CONTENT_ALWAYS_EMPTY
private static final int	ST_CONTENT_CHUNK
private static final int	ST_CONTENT_NON_CHUNK
private static final int	ST_INIT
private int	state
private static final float	TRAILERS_WEIGHT_HISTORICAL
private static final float	TRAILERS_WEIGHT_NEW
private float	trailersEncodedSizeAccumulator	Used to calculate an exponential moving average of the encoded size of the trailers for a guess for future buffer allocations.
private static final byte[]	ZERO_CRLF_CRLF
private static final ByteBuf	ZERO_CRLF_CRLF_BUF
private static final int	ZERO_CRLF_MEDIUM

Constructor Summary

Constructors

Constructor	Description
HttpObjectEncoder()

Method Summary

Modifier and Type	Method	Description
boolean	acceptOutboundMessage(Object msg)	Returns true if the given message should be handled.
private static void	addEncodedLengthHex(ChannelHandlerContext ctx, long contentLength, List<Object> out)
private static boolean	bypassEncoderIfEmpty(ByteBuf msg, List<Object> out)
private static boolean	checkContentState(int state)
protected void	encode(ChannelHandlerContext ctx, Object msg, List<Object> out)	Encode from one message to an other.
protected static void	encodeAscii(String s, ByteBuf buf)	Deprecated.
private void	encodeByteBufAndTrailers(int state, ChannelHandlerContext ctx, List<Object> out, ByteBuf content, HttpHeaders trailingHeaders)
private void	encodeByteBufContent(ChannelHandlerContext ctx, ByteBuf content, List<Object> out)
private void	encodeByteBufHttpContent(int state, ChannelHandlerContext ctx, ByteBuf buf, ByteBuf content, HttpHeaders trailingHeaders, List<Object> out)
private void	encodeChunkedHttpContent(ChannelHandlerContext ctx, ByteBuf content, HttpHeaders trailingHeaders, List<Object> out)
private static boolean	encodeContentNonChunk(List<Object> out, ByteBuf buf, ByteBuf content)
private static void	encodedChunkedFileRegionContent(ChannelHandlerContext ctx, FileRegion msg, List<Object> out)
private static int	encodeEmptyLastHttpContent(int state, List<Object> out)
private void	encodeFileRegionContent(ChannelHandlerContext ctx, FileRegion msg, List<Object> out)
private void	encodeFullHttpMessage(ChannelHandlerContext ctx, Object o, List<Object> out)
protected void	encodeHeaders(HttpHeaders headers, ByteBuf buf)	Encode the HttpHeaders into a ByteBuf.
private void	encodeHttpContent(ChannelHandlerContext ctx, HttpContent msg, List<Object> out)
private void	encodeHttpMessageLastContent(ChannelHandlerContext ctx, H m, List<Object> out)
private void	encodeHttpMessageNotLastContent(ChannelHandlerContext ctx, H m, List<Object> out)
private ByteBuf	encodeInitHttpMessage(ChannelHandlerContext ctx, H m)
protected abstract void	encodeInitialLine(ByteBuf buf, H message)
private void	encodeJustHttpMessage(ChannelHandlerContext ctx, H m, List<Object> out)
private void	encodeLastHttpContent(ChannelHandlerContext ctx, LastHttpContent msg, List<Object> out)
private void	encodeNotHttpMessageContentTypes(ChannelHandlerContext ctx, Object msg, List<Object> out)
private void	encodeTrailingHeaders(ChannelHandlerContext ctx, HttpHeaders trailingHeaders, List<Object> out)
protected boolean	isContentAlwaysEmpty(H msg)	Determine whether a message has a content or not.
private static int	padSizeForAccumulation(int readableBytes)	Add some additional overhead to the buffer.
protected void	sanitizeHeadersBeforeEncode(H msg, boolean isAlwaysEmpty)	Allows to sanitize headers of the message before encoding these.
private static void	throwUnexpectedMessageTypeEx(Object msg, int state)
void	write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)	Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
private static void	writeOutList(ChannelHandlerContext ctx, List<Object> out, ChannelPromise promise)
private static void	writePromiseCombiner(ChannelHandlerContext ctx, List<Object> out, ChannelPromise promise)
private static void	writeVoidPromise(ChannelHandlerContext ctx, List<Object> out)

Methods inherited from class io.netty.channel.ChannelOutboundHandlerAdapter

bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, exceptionCaught, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

exceptionCaught, handlerAdded, handlerRemoved

Field Details

COPY_CONTENT_THRESHOLD

private static final int COPY_CONTENT_THRESHOLD

See Also:

• Constant Field Values

CRLF_SHORT

static final int CRLF_SHORT

See Also:

• Constant Field Values

ZERO_CRLF_MEDIUM

private static final int ZERO_CRLF_MEDIUM

See Also:

• Constant Field Values

ZERO_CRLF_CRLF

private static final byte[] ZERO_CRLF_CRLF

CRLF_BUF

private static final ByteBuf CRLF_BUF

ZERO_CRLF_CRLF_BUF

private static final ByteBuf ZERO_CRLF_CRLF_BUF

HEADERS_WEIGHT_NEW

private static final float HEADERS_WEIGHT_NEW

See Also:

• Constant Field Values

HEADERS_WEIGHT_HISTORICAL

private static final float HEADERS_WEIGHT_HISTORICAL

See Also:

• Constant Field Values

TRAILERS_WEIGHT_NEW

private static final float TRAILERS_WEIGHT_NEW

See Also:

• Constant Field Values

TRAILERS_WEIGHT_HISTORICAL

private static final float TRAILERS_WEIGHT_HISTORICAL

See Also:

• Constant Field Values

ST_INIT

private static final int ST_INIT

See Also:

• Constant Field Values

ST_CONTENT_NON_CHUNK

private static final int ST_CONTENT_NON_CHUNK

See Also:

• Constant Field Values

ST_CONTENT_CHUNK

private static final int ST_CONTENT_CHUNK

See Also:

• Constant Field Values

ST_CONTENT_ALWAYS_EMPTY

private static final int ST_CONTENT_ALWAYS_EMPTY

See Also:

• Constant Field Values

state

private int state

headersEncodedSizeAccumulator

private float headersEncodedSizeAccumulator

Used to calculate an exponential moving average of the encoded size of the initial line and the headers for a guess for future buffer allocations.

trailersEncodedSizeAccumulator

private float trailersEncodedSizeAccumulator

Used to calculate an exponential moving average of the encoded size of the trailers for a guess for future buffer allocations.

out

private final List<Object> out

Constructor Details

HttpObjectEncoder

public HttpObjectEncoder()

Method Details

checkContentState

private static boolean checkContentState(int state)

write

public void write(ChannelHandlerContext ctx,
 Object msg,
 ChannelPromise promise)
           throws Exception

Description copied from class: ChannelOutboundHandlerAdapter

Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

write in interface ChannelOutboundHandler

Overrides:

write in class MessageToMessageEncoder<Object>

Parameters:

ctx - the ChannelHandlerContext for which the write operation is made

msg - the message to write

promise - the ChannelPromise to notify once the operation completes

Throws:

Exception - thrown if an error occurs

writeOutList

private static void writeOutList(ChannelHandlerContext ctx,
 List<Object> out,
 ChannelPromise promise)

writeVoidPromise

private static void writeVoidPromise(ChannelHandlerContext ctx,
 List<Object> out)

writePromiseCombiner

private static void writePromiseCombiner(ChannelHandlerContext ctx,
 List<Object> out,
 ChannelPromise promise)

encode

protected void encode(ChannelHandlerContext ctx,
 Object msg,
 List<Object> out)
               throws Exception

Description copied from class: MessageToMessageEncoder

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

Specified by:

encode in class MessageToMessageEncoder<Object>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

Throws:

Exception - is thrown if an error occurs

encodeJustHttpMessage

private void encodeJustHttpMessage(ChannelHandlerContext ctx,
 H m,
 List<Object> out)
                            throws Exception

Throws:

Exception

encodeByteBufHttpContent

private void encodeByteBufHttpContent(int state,
 ChannelHandlerContext ctx,
 ByteBuf buf,
 ByteBuf content,
 HttpHeaders trailingHeaders,
 List<Object> out)

encodeHttpMessageNotLastContent

private void encodeHttpMessageNotLastContent(ChannelHandlerContext ctx,
 H m,
 List<Object> out)
                                      throws Exception

Throws:

Exception

encodeHttpMessageLastContent

private void encodeHttpMessageLastContent(ChannelHandlerContext ctx,
 H m,
 List<Object> out)
                                   throws Exception

Throws:

Exception

encodeNotHttpMessageContentTypes

private void encodeNotHttpMessageContentTypes(ChannelHandlerContext ctx,
 Object msg,
 List<Object> out)

encodeFullHttpMessage

private void encodeFullHttpMessage(ChannelHandlerContext ctx,
 Object o,
 List<Object> out)
                            throws Exception

Throws:

Exception

encodeContentNonChunk

private static boolean encodeContentNonChunk(List<Object> out,
 ByteBuf buf,
 ByteBuf content)

throwUnexpectedMessageTypeEx

private static void throwUnexpectedMessageTypeEx(Object msg,
 int state)

encodeFileRegionContent

private void encodeFileRegionContent(ChannelHandlerContext ctx,
 FileRegion msg,
 List<Object> out)

bypassEncoderIfEmpty

private static boolean bypassEncoderIfEmpty(ByteBuf msg,
 List<Object> out)

encodeByteBufContent

private void encodeByteBufContent(ChannelHandlerContext ctx,
 ByteBuf content,
 List<Object> out)

encodeEmptyLastHttpContent

private static int encodeEmptyLastHttpContent(int state,
 List<Object> out)

encodeLastHttpContent

private void encodeLastHttpContent(ChannelHandlerContext ctx,
 LastHttpContent msg,
 List<Object> out)

encodeHttpContent

private void encodeHttpContent(ChannelHandlerContext ctx,
 HttpContent msg,
 List<Object> out)

encodeByteBufAndTrailers

private void encodeByteBufAndTrailers(int state,
 ChannelHandlerContext ctx,
 List<Object> out,
 ByteBuf content,
 HttpHeaders trailingHeaders)

encodeChunkedHttpContent

private void encodeChunkedHttpContent(ChannelHandlerContext ctx,
 ByteBuf content,
 HttpHeaders trailingHeaders,
 List<Object> out)

encodeTrailingHeaders

private void encodeTrailingHeaders(ChannelHandlerContext ctx,
 HttpHeaders trailingHeaders,
 List<Object> out)

encodeInitHttpMessage

private ByteBuf encodeInitHttpMessage(ChannelHandlerContext ctx,
 H m)
                               throws Exception

Throws:

Exception

encodeHeaders

protected void encodeHeaders(HttpHeaders headers,
 ByteBuf buf)

Encode the HttpHeaders into a ByteBuf.

encodedChunkedFileRegionContent

private static void encodedChunkedFileRegionContent(ChannelHandlerContext ctx,
 FileRegion msg,
 List<Object> out)

addEncodedLengthHex

private static void addEncodedLengthHex(ChannelHandlerContext ctx,
 long contentLength,
 List<Object> out)

sanitizeHeadersBeforeEncode

protected void sanitizeHeadersBeforeEncode(H msg,
 boolean isAlwaysEmpty)

Allows to sanitize headers of the message before encoding these.

isContentAlwaysEmpty

protected boolean isContentAlwaysEmpty(H msg)

Determine whether a message has a content or not. Some message may have headers indicating a content without having an actual content, e.g the response to an HEAD or CONNECT request.

Parameters:

msg - the message to test

Returns:

true to signal the message has no content

acceptOutboundMessage

public boolean acceptOutboundMessage(Object msg)
                              throws Exception

Description copied from class: MessageToMessageEncoder

Returns true if the given message should be handled. If false it will be passed to the next ChannelOutboundHandler in the ChannelPipeline.

Overrides:

acceptOutboundMessage in class MessageToMessageEncoder<Object>

Throws:

Exception

padSizeForAccumulation

private static int padSizeForAccumulation(int readableBytes)

Add some additional overhead to the buffer. The rational is that it is better to slightly over allocate and waste some memory, rather than under allocate and require a resize/copy.

Parameters:

readableBytes - The readable bytes in the buffer.

Returns:

The readableBytes with some additional padding.

encodeAscii

@Deprecated
protected static void encodeAscii(String s,
 ByteBuf buf)

Deprecated.

encodeInitialLine

protected abstract void encodeInitialLine(ByteBuf buf,
 H message)
                                   throws Exception

Throws:

Exception