Class WebSocketServerExtensionHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.codec.http.websocketx.extensions.WebSocketServerExtensionHandler

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

Direct Known Subclasses:

WebSocketServerCompressionHandler

public class WebSocketServerExtensionHandler
extends ChannelDuplexHandler

This handler negotiates and initializes the WebSocket Extensions. It negotiates the extensions based on the client desired order, ensures that the successfully negotiated extensions are consistent between them, and initializes the channel pipeline with the extension decoder and encoder. Find a basic implementation for compression extensions at io.netty.handler.codec.http.websocketx.extensions.compression.WebSocketServerCompressionHandler.

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Modifier and Type	Interface	Description
static @interface	ChannelHandler.Sharable	Indicates that the same instance of the annotated ChannelHandler can be added to one or more ChannelPipelines multiple times without a race condition.

Constructor Summary

Constructors

Constructor	Description
WebSocketServerExtensionHandler(int maxPipelineDepth, WebSocketServerExtensionHandshaker... extensionHandshakers)	Constructor
WebSocketServerExtensionHandler(WebSocketServerExtensionHandshaker... extensionHandshakers)	Constructor

Method Summary

Modifier and Type	Method	Description
void	channelRead(ChannelHandlerContext ctx, Object msg)	Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected void	onHttpRequestChannelRead(ChannelHandlerContext ctx, HttpRequest request)	This is a method exposed to perform fail-fast checks of user-defined http types.
protected void	onHttpResponseWrite(ChannelHandlerContext ctx, HttpResponse response, ChannelPromise promise)	This is a method exposed to perform fail-fast checks of user-defined http types.
void	write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)	Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.

Methods inherited from class ChannelDuplexHandler

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

Modifier and Type	Method	Description
void	bind(ChannelHandlerContext ctx, SocketAddress localAddress, ChannelPromise promise)	Calls ChannelOutboundInvoker.bind(SocketAddress, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	close(ChannelHandlerContext ctx, ChannelPromise promise)	Calls ChannelOutboundInvoker.close(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise)	Calls ChannelOutboundInvoker.connect(SocketAddress, SocketAddress, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	deregister(ChannelHandlerContext ctx, ChannelPromise promise)	Calls ChannelOutboundInvoker.deregister(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	disconnect(ChannelHandlerContext ctx, ChannelPromise promise)	Calls ChannelOutboundInvoker.disconnect(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	flush(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.flush() to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	read(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.read() to forward to the next ChannelOutboundHandler in the ChannelPipeline.

Methods inherited from class ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Modifier and Type	Method	Description
void	channelActive(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelActive() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelInactive(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelInactive() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelReadComplete(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelRegistered(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelRegistered() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelUnregistered(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelUnregistered() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelWritabilityChanged(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelWritabilityChanged() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	exceptionCaught(ChannelHandlerContext ctx, Throwable cause)	Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline.
void	userEventTriggered(ChannelHandlerContext ctx, Object evt)	Calls ChannelHandlerContext.fireUserEventTriggered(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Modifier and Type	Method	Description
protected void	ensureNotSharable()	Throws IllegalStateException if ChannelHandlerAdapter.isSharable() returns true
void	handlerAdded(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
void	handlerRemoved(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
boolean	isSharable()	Return true if the implementation is ChannelHandler.Sharable and so can be added to different ChannelPipelines.

Methods inherited from class Object

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

Constructor Details

WebSocketServerExtensionHandler

public WebSocketServerExtensionHandler(WebSocketServerExtensionHandshaker... extensionHandshakers)

Constructor

Parameters:

extensionHandshakers - The extension handshaker in priority order. A handshaker could be repeated many times with fallback configuration.

WebSocketServerExtensionHandler

public WebSocketServerExtensionHandler(int maxPipelineDepth,
 WebSocketServerExtensionHandshaker... extensionHandshakers)

Constructor

Parameters:

maxPipelineDepth - The maximum number of pipelined upgrade requests.

extensionHandshakers - The extension handshaker in priority order. A handshaker could be repeated many times with fallback configuration.

Method Details

channelRead

public void channelRead(ChannelHandlerContext ctx,
 Object msg)
                 throws Exception

Description copied from class: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelRead in interface ChannelInboundHandler

Overrides:

channelRead in class ChannelInboundHandlerAdapter

Throws:

Exception

onHttpRequestChannelRead

protected void onHttpRequestChannelRead(ChannelHandlerContext ctx,
 HttpRequest request)
                                 throws Exception

This is a method exposed to perform fail-fast checks of user-defined http types.

eg:
If the user has defined a specific HttpRequest type i.e.CustomHttpRequest and channelRead(ChannelHandlerContext, Object) can receive LastHttpContent.EMPTY_LAST_CONTENT msg types too, can override it like this:

    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg != LastHttpContent.EMPTY_LAST_CONTENT) {
            if (msg instanceof CustomHttpRequest) {
                onHttpRequestChannelRead(ctx, (CustomHttpRequest) msg);
            } else {
                // if it's handling other HttpRequest types it MUST use onHttpRequestChannelRead again
                // or have to delegate it to super.channelRead (that can perform redundant checks).
                // If msg is not implementing HttpRequest, it can call ctx.fireChannelRead(msg) on it
                // ...
                super.channelRead(ctx, msg);
            }
        } else {
            // given that msg isn't a HttpRequest type we can just skip calling super.channelRead
            ctx.fireChannelRead(msg);
        }
    }

IMPORTANT: It already call super.channelRead(ctx, request) before returning.

Throws:

Exception

write

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

Description copied from class: ChannelDuplexHandler

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 ChannelDuplexHandler

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

onHttpResponseWrite

protected void onHttpResponseWrite(ChannelHandlerContext ctx,
 HttpResponse response,
 ChannelPromise promise)
                            throws Exception

This is a method exposed to perform fail-fast checks of user-defined http types.

eg:
If the user has defined a specific HttpResponse type i.e.CustomHttpResponse and write(ChannelHandlerContext, Object, ChannelPromise) can receive ByteBuf msg types too, it can be overridden like this:

    public void write(final ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
        if (msg != Unpooled.EMPTY_BUFFER invalid input: '&'invalid input: '&' !(msg instanceof ByteBuf)) {
            if (msg instanceof CustomHttpResponse) {
                onHttpResponseWrite(ctx, (CustomHttpResponse) msg, promise);
            } else {
                // if it's handling other HttpResponse types it MUST use onHttpResponseWrite again
                // or have to delegate it to super.write (that can perform redundant checks).
                // If msg is not implementing HttpResponse, it can call ctx.write(msg, promise) on it
                // ...
                super.write(ctx, msg, promise);
            }
        } else {
            // given that msg isn't a HttpResponse type we can just skip calling super.write
            ctx.write(msg, promise);
        }
    }

IMPORTANT: It already call super.write(ctx, response, promise) before returning.

Throws:

Exception