io.netty.handler.codec.http2

Interface Http2FrameListener

All Known Implementing Classes:

DelegatingDecompressorFrameListener, Http2EventAdapter, Http2FrameAdapter, Http2FrameListenerDecorator, InboundHttp2ToHttpAdapter

@UnstableApi
public interface Http2FrameListener

An listener of HTTP/2 frames.

Method Summary

Modifier and Type	Method and Description
int	onDataRead(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream) Handles an inbound DATA frame.
void	onGoAwayRead(ChannelHandlerContext ctx, int lastStreamId, long errorCode, ByteBuf debugData) Handles an inbound GO_AWAY frame.
void	onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int padding, boolean endOfStream) Handles an inbound HEADERS frame.
void	onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int streamDependency, short weight, boolean exclusive, int padding, boolean endOfStream) Handles an inbound HEADERS frame with priority information specified.
void	onPingAckRead(ChannelHandlerContext ctx, ByteBuf data) Handles an inbound PING acknowledgment.
void	onPingRead(ChannelHandlerContext ctx, ByteBuf data) Handles an inbound PING frame.
void	onPriorityRead(ChannelHandlerContext ctx, int streamId, int streamDependency, short weight, boolean exclusive) Handles an inbound PRIORITY frame.
void	onPushPromiseRead(ChannelHandlerContext ctx, int streamId, int promisedStreamId, Http2Headers headers, int padding) Handles an inbound PUSH_PROMISE frame.
void	onRstStreamRead(ChannelHandlerContext ctx, int streamId, long errorCode) Handles an inbound RST_STREAM frame.
void	onSettingsAckRead(ChannelHandlerContext ctx) Handles an inbound SETTINGS acknowledgment frame.
void	onSettingsRead(ChannelHandlerContext ctx, Http2Settings settings) Handles an inbound SETTINGS frame.
void	onUnknownFrame(ChannelHandlerContext ctx, byte frameType, int streamId, Http2Flags flags, ByteBuf payload) Handler for a frame not defined by the HTTP/2 spec.
void	onWindowUpdateRead(ChannelHandlerContext ctx, int streamId, int windowSizeIncrement) Handles an inbound WINDOW_UPDATE frame.

Method Detail

onDataRead

int onDataRead(ChannelHandlerContext ctx,
               int streamId,
               ByteBuf data,
               int padding,
               boolean endOfStream)
        throws Http2Exception

Handles an inbound DATA frame.

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

data - payload buffer for the frame. This buffer will be released by the codec.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endOfStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Returns:

the number of bytes that have been processed by the application. The returned bytes are used by the inbound flow controller to determine the appropriate time to expand the inbound flow control window (i.e. send WINDOW_UPDATE). Returning a value equal to the length of data + padding will effectively opt-out of application-level flow control for this frame. Returning a value less than the length of data + padding will defer the returning of the processed bytes, which the application must later return via Http2LocalFlowController.consumeBytes(Http2Stream, int). The returned value must be >= 0 and <= data.readableBytes() + padding.

Throws:

Http2Exception

onHeadersRead

void onHeadersRead(ChannelHandlerContext ctx,
                   int streamId,
                   Http2Headers headers,
                   int padding,
                   boolean endOfStream)
            throws Http2Exception

Handles an inbound HEADERS frame.

Only one of the following methods will be called for each HEADERS frame sequence. One will be called when the END_HEADERS flag has been received.

• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, boolean)
• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, short, boolean, int, boolean)
• onPushPromiseRead(ChannelHandlerContext, int, int, Http2Headers, int)

To say it another way; the Http2Headers will contain all of the headers for the current message exchange step (additional queuing is not necessary).

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

headers - the received headers.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endOfStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Throws:

Http2Exception

onHeadersRead

void onHeadersRead(ChannelHandlerContext ctx,
                   int streamId,
                   Http2Headers headers,
                   int streamDependency,
                   short weight,
                   boolean exclusive,
                   int padding,
                   boolean endOfStream)
            throws Http2Exception

Handles an inbound HEADERS frame with priority information specified. Only called if END_HEADERS encountered.

Only one of the following methods will be called for each HEADERS frame sequence. One will be called when the END_HEADERS flag has been received.

• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, boolean)
• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, short, boolean, int, boolean)
• onPushPromiseRead(ChannelHandlerContext, int, int, Http2Headers, int)

To say it another way; the Http2Headers will contain all of the headers for the current message exchange step (additional queuing is not necessary).

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

headers - the received headers.

streamDependency - the stream on which this stream depends, or 0 if dependent on the connection.

weight - the new weight for the stream.

exclusive - whether or not the stream should be the exclusive dependent of its parent.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endOfStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Throws:

Http2Exception

onPriorityRead

void onPriorityRead(ChannelHandlerContext ctx,
                    int streamId,
                    int streamDependency,
                    short weight,
                    boolean exclusive)
             throws Http2Exception

Handles an inbound PRIORITY frame.

Note that is it possible to have this method called and no stream object exist for either streamId, streamDependency, or both. This is because the PRIORITY frame can be sent/received when streams are in the CLOSED state.

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

streamDependency - the stream on which this stream depends, or 0 if dependent on the connection.

weight - the new weight for the stream.

exclusive - whether or not the stream should be the exclusive dependent of its parent.

Throws:

Http2Exception

onRstStreamRead

void onRstStreamRead(ChannelHandlerContext ctx,
                     int streamId,
                     long errorCode)
              throws Http2Exception

Handles an inbound RST_STREAM frame.

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the stream that is terminating.

errorCode - the error code identifying the type of failure.

Throws:

Http2Exception

onSettingsAckRead

void onSettingsAckRead(ChannelHandlerContext ctx)
                throws Http2Exception

Handles an inbound SETTINGS acknowledgment frame.

Parameters:

ctx - the context from the handler where the frame was read.

Throws:

Http2Exception

onSettingsRead

void onSettingsRead(ChannelHandlerContext ctx,
                    Http2Settings settings)
             throws Http2Exception

Handles an inbound SETTINGS frame.

Parameters:

ctx - the context from the handler where the frame was read.

settings - the settings received from the remote endpoint.

Throws:

Http2Exception

onPingRead

void onPingRead(ChannelHandlerContext ctx,
                ByteBuf data)
         throws Http2Exception

Handles an inbound PING frame.

Parameters:

ctx - the context from the handler where the frame was read.

data - the payload of the frame. If this buffer needs to be retained by the listener they must make a copy.

Throws:

Http2Exception

onPingAckRead

void onPingAckRead(ChannelHandlerContext ctx,
                   ByteBuf data)
            throws Http2Exception

Handles an inbound PING acknowledgment.

Parameters:

ctx - the context from the handler where the frame was read.

data - the payload of the frame. If this buffer needs to be retained by the listener they must make a copy.

Throws:

Http2Exception

onPushPromiseRead

void onPushPromiseRead(ChannelHandlerContext ctx,
                       int streamId,
                       int promisedStreamId,
                       Http2Headers headers,
                       int padding)
                throws Http2Exception

Handles an inbound PUSH_PROMISE frame. Only called if END_HEADERS encountered.

Promised requests MUST be authoritative, cacheable, and safe. See [RFC http2], Section 8.2.

Only one of the following methods will be called for each HEADERS frame sequence. One will be called when the END_HEADERS flag has been received.

• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, boolean)
• onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, short, boolean, int, boolean)
• onPushPromiseRead(ChannelHandlerContext, int, int, Http2Headers, int)

To say it another way; the Http2Headers will contain all of the headers for the current message exchange step (additional queuing is not necessary).

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the stream the frame was sent on.

promisedStreamId - the ID of the promised stream.

headers - the received headers.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

Throws:

Http2Exception

onGoAwayRead

void onGoAwayRead(ChannelHandlerContext ctx,
                  int lastStreamId,
                  long errorCode,
                  ByteBuf debugData)
           throws Http2Exception

Handles an inbound GO_AWAY frame.

Parameters:

ctx - the context from the handler where the frame was read.

lastStreamId - the last known stream of the remote endpoint.

errorCode - the error code, if abnormal closure.

debugData - application-defined debug data. If this buffer needs to be retained by the listener they must make a copy.

Throws:

Http2Exception

onWindowUpdateRead

void onWindowUpdateRead(ChannelHandlerContext ctx,
                        int streamId,
                        int windowSizeIncrement)
                 throws Http2Exception

Handles an inbound WINDOW_UPDATE frame.

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the stream the frame was sent on.

windowSizeIncrement - the increased number of bytes of the remote endpoint's flow control window.

Throws:

Http2Exception

onUnknownFrame

void onUnknownFrame(ChannelHandlerContext ctx,
                    byte frameType,
                    int streamId,
                    Http2Flags flags,
                    ByteBuf payload)
             throws Http2Exception

Handler for a frame not defined by the HTTP/2 spec.

Parameters:

ctx - the context from the handler where the frame was read.

frameType - the frame type from the HTTP/2 header.

streamId - the stream the frame was sent on.

flags - the flags in the frame header.

payload - the payload of the frame.

Throws:

Http2Exception