io.netty.handler.codec.http.websocketx

Class WebSocketClientProtocolHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.handler.codec.MessageToMessageDecoder<WebSocketFrame>

io.netty.handler.codec.http.websocketx.WebSocketClientProtocolHandler

All Implemented Interfaces:

ChannelHandler

public class WebSocketClientProtocolHandler
extends MessageToMessageDecoder<WebSocketFrame>

This handler does all the heavy lifting for you to run a websocket client. It takes care of websocket handshaking as well as processing of Ping, Pong frames. Text and Binary data frames are passed to the next handler in the pipeline (implemented by you) for processing. Also the close frame is passed to the next handler as you may want inspect it before close the connection if the handleCloseFrames is false, default is true. This implementation will establish the websocket connection once the connection to the remote server was complete. To know once a handshake was done you can intercept the ChannelHandler.userEventTriggered(ChannelHandlerContext, Object) and check if the event was of type WebSocketClientProtocolHandler.ClientHandshakeStateEvent.HANDSHAKE_ISSUED or WebSocketClientProtocolHandler.ClientHandshakeStateEvent.HANDSHAKE_COMPLETE.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WebSocketClientProtocolHandler.ClientHandshakeStateEvent Events that are fired to notify about handshake status

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

ChannelHandler.Sharable, ChannelHandler.Skip

Constructor Summary

Constructors

Constructor and Description
WebSocketClientProtocolHandler(URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength) Base constructor
WebSocketClientProtocolHandler(URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength, boolean handleCloseFrames) Base constructor
WebSocketClientProtocolHandler(URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength, boolean handleCloseFrames, boolean performMasking, boolean allowMaskMismatch) Base constructor
WebSocketClientProtocolHandler(WebSocketClientHandshaker handshaker) Base constructor
WebSocketClientProtocolHandler(WebSocketClientHandshaker handshaker, boolean handleCloseFrames) Base constructor

Method Summary

Methods

Modifier and Type	Method and Description
protected void	decode(ChannelHandlerContext ctx, WebSocketFrame frame, List<Object> out) Decode from one message to an other.
void	exceptionCaught(ChannelHandlerContext ctx, Throwable cause) Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline.
void	handlerAdded(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.
WebSocketClientHandshaker	handshaker() Returns the used handshaker

Methods inherited from class io.netty.handler.codec.MessageToMessageDecoder

acceptInboundMessage, channelRead

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, flush, handlerRemoved, isSharable, read, userEventTriggered, write

Methods inherited from class java.lang.Object

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

Constructor Detail

WebSocketClientProtocolHandler

public WebSocketClientProtocolHandler(URI webSocketURL,
                              WebSocketVersion version,
                              String subprotocol,
                              boolean allowExtensions,
                              HttpHeaders customHeaders,
                              int maxFramePayloadLength,
                              boolean handleCloseFrames,
                              boolean performMasking,
                              boolean allowMaskMismatch)

Base constructor

Parameters:

webSocketURL - URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be sent to this URL.

version - Version of web socket specification to use to connect to the server

subprotocol - Sub protocol request sent to the server.

customHeaders - Map of custom headers to add to the client request

maxFramePayloadLength - Maximum length of a frame's payload

handleCloseFrames - true if close frames should not be forwarded and just close the channel

performMasking - Whether to mask all written websocket frames. This must be set to true in order to be fully compatible with the websocket specifications. Client applications that communicate with a non-standard server which doesn't require masking might set this to false to achieve a higher performance.

allowMaskMismatch - Allows to loosen the masking requirement on received frames. When this is set to false then also frames which are not masked properly according to the standard will still be accepted.

WebSocketClientProtocolHandler

public WebSocketClientProtocolHandler(URI webSocketURL,
                              WebSocketVersion version,
                              String subprotocol,
                              boolean allowExtensions,
                              HttpHeaders customHeaders,
                              int maxFramePayloadLength,
                              boolean handleCloseFrames)

Base constructor

Parameters:

webSocketURL - URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be sent to this URL.

version - Version of web socket specification to use to connect to the server

subprotocol - Sub protocol request sent to the server.

customHeaders - Map of custom headers to add to the client request

maxFramePayloadLength - Maximum length of a frame's payload

handleCloseFrames - true if close frames should not be forwarded and just close the channel

WebSocketClientProtocolHandler

public WebSocketClientProtocolHandler(URI webSocketURL,
                              WebSocketVersion version,
                              String subprotocol,
                              boolean allowExtensions,
                              HttpHeaders customHeaders,
                              int maxFramePayloadLength)

Base constructor

Parameters:

webSocketURL - URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be sent to this URL.

version - Version of web socket specification to use to connect to the server

subprotocol - Sub protocol request sent to the server.

customHeaders - Map of custom headers to add to the client request

maxFramePayloadLength - Maximum length of a frame's payload

WebSocketClientProtocolHandler

public WebSocketClientProtocolHandler(WebSocketClientHandshaker handshaker,
                              boolean handleCloseFrames)

Base constructor

Parameters:

handshaker - The WebSocketClientHandshaker which will be used to issue the handshake once the connection was established to the remote peer.

handleCloseFrames - true if close frames should not be forwarded and just close the channel

WebSocketClientProtocolHandler

public WebSocketClientProtocolHandler(WebSocketClientHandshaker handshaker)

Base constructor

Parameters:

handshaker - The WebSocketClientHandshaker which will be used to issue the handshake once the connection was established to the remote peer.

Method Detail

handshaker

public WebSocketClientHandshaker handshaker()

Returns the used handshaker

decode

protected void decode(ChannelHandlerContext ctx,
          WebSocketFrame frame,
          List<Object> out)
               throws Exception

Description copied from class: MessageToMessageDecoder

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

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

frame - the message to decode to an other one

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error accour

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerAdded in interface ChannelHandler

Overrides:

handlerAdded in class ChannelHandlerAdapter

exceptionCaught

public void exceptionCaught(ChannelHandlerContext ctx,
                   Throwable cause)
                     throws Exception

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

exceptionCaught in interface ChannelHandler

Overrides:

exceptionCaught in class ChannelHandlerAdapter

Throws:

Exception