Netty5/Transport 5.0.0.Alpha5 · io.netty5.channel.ChannelPipeline

A list of ChannelHandlers which handles or intercepts inbound events and outbound operations of a Channel. ChannelPipeline implements an advanced form of the Intercepting Filter pattern to give a user full control over how an event is handled and how the ChannelHandlers in a pipeline interact with each other.

Creation of a pipeline

Each channel has its own pipeline and it is created automatically when a new channel is created.

How an event flows in a pipeline

The following diagram describes how I/O events are processed by ChannelHandlers in a ChannelPipeline typically. An I/O event is handled by a ChannelHandler (which may handle inbound or / and outbound events) and be forwarded to its closest handler by calling the event propagation methods defined in ChannelHandlerContext, such as ChannelHandlerContext#fireChannelRead(Object) and ChannelHandlerContext#write(Object).

                                                I/O Request
                                           via Channel or
                                       ChannelHandlerContext
                                                     |
 +---------------------------------------------------+---------------+
 |                           ChannelPipeline         |               |
 |                                                  \|/              |
 |    +---------------------+            +-----------+----------+    |
 |    | Inbound Handler  N  |            | Outbound Handler  1  |    |
 |    +----------+----------+            +-----------+----------+    |
 |              /|\                                  |               |
 |               |                                  \|/              |
 |    +----------+----------+            +-----------+----------+    |
 |    | Inbound Handler N-1 |            | Outbound Handler  2  |    |
 |    +----------+----------+            +-----------+----------+    |
 |              /|\                                  .               |
 |               .                                   .               |
 | ChannelHandlerContext.fireIN_EVT() ChannelHandlerContext.OUT_EVT()|
 |        [ method call]                       [method call]         |
 |               .                                   .               |
 |               .                                  \|/              |
 |    +----------+----------+            +-----------+----------+    |
 |    | Inbound Handler  2  |            | Outbound Handler M-1 |    |
 |    +----------+----------+            +-----------+----------+    |
 |              /|\                                  |               |
 |               |                                  \|/              |
 |    +----------+----------+            +-----------+----------+    |
 |    | Inbound Handler  1  |            | Outbound Handler  M  |    |
 |    +----------+----------+            +-----------+----------+    |
 |              /|\                                  |               |
 +---------------+-----------------------------------+---------------+
                 |                                  \|/
 +---------------+-----------------------------------+---------------+
 |               |                                   |               |
 |       [ Socket.read() ]                    [ Socket.write() ]     |
 |                                                                   |
 |  Netty Internal I/O Threads (Transport Implementation)            |
 +-------------------------------------------------------------------+

An inbound event is handled by the inbound handlers in the bottom-up direction as shown on the left side of the diagram. An inbound handler usually handles the inbound data generated by the I/O thread on the bottom of the diagram. The inbound data is often read from a remote peer via the actual input operation such as SocketChannel#read(ByteBuffer). If an inbound event goes beyond the top inbound handler, it is discarded silently, or logged if it needs your attention.

An outbound event is handled by the outbound handler in the top-down direction as shown on the right side of the diagram. An outbound handler usually generates or transforms the outbound traffic such as write requests. If an outbound event goes beyond the bottom outbound handler, it is handled by an I/O thread associated with the Channel. The I/O thread often performs the actual output operation such as SocketChannel#write(ByteBuffer).

For example, let us assume that we created the following pipeline:

ChannelPipeline p = ...;
p.addLast("1", new InboundHandlerA());
p.addLast("2", new InboundHandlerB());
p.addLast("3", new OutboundHandlerA());
p.addLast("4", new OutboundHandlerB());
p.addLast("5", new InboundOutboundHandlerX());

In the example above, the class whose name starts with Inbound means it is an inbound handler. The class whose name starts with Outbound means it is a outbound handler.

In the given example configuration, the handler evaluation order is 1, 2, 3, 4, 5 when an event goes inbound. When an event goes outbound, the order is 5, 4, 3, 2, 1. On top of this principle, ChannelPipeline skips the evaluation of certain handlers to shorten the stack depth:

3 and 4 don't implement inbound handling methods of ChannelHandler, and therefore the actual evaluation order of an inbound event will be: 1, 2, and 5.
1 and 2 don't implement outbound handling methods of ChannelHandler, and therefore the actual evaluation order of an outbound event will be: 5, 4, and 3.
If 5 implements both inbound and outbound handling methods of ChannelHandler, the evaluation order of an inbound and a outbound event could be 125 and 543 respectively.

Forwarding an event to the next handler

As you might noticed in the diagram shows, a handler has to invoke the event propagation methods in ChannelHandlerContext to forward an event to its next handler. Those methods include:

and the following example shows how the event propagation is usually done:

public class MyInboundHandler implements ChannelHandler {
    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        System.out.println("Connected!");
        ctx.fireChannelActive();
    }
}

public class MyOutboundHandler implements ChannelHandler {
    @Override
    public Future<Void> close(ChannelHandlerContext ctx) {
        System.out.println("Closing ..");
        return ctx.close();
    }
}

Building a pipeline

A user is supposed to have one or more ChannelHandlers in a pipeline to receive I/O events (e.g. read) and to request I/O operations (e.g. write and close). For example, a typical server will have the following handlers in each channel's pipeline, but your mileage may vary depending on the complexity and characteristics of the protocol and business logic:

Protocol Decoder - translates binary data (e.g. Buffer) into a Java object.
Protocol Encoder - translates a Java object into binary data.
Business Logic Handler - performs the actual business logic (e.g. database access).

and it could be represented as shown in the following example:

...

ChannelPipeline pipeline = ch.pipeline();

pipeline.addLast("decoder", new MyProtocolDecoder());
pipeline.addLast("encoder", new MyProtocolEncoder());

// If your business logic does block or take a lot of time you should offload the work to an extra
// java.util.concurrent.Executor to ensure you don't block the EventLoop.
pipeline.addLast("handler",  new MyBusinessLogicHandler());

Thread safety

A ChannelHandler can be added or removed at any time because a ChannelPipeline is thread safe. For example, you can insert an encryption handler when sensitive information is about to be exchanged, and remove it after the exchange.

Method Summary

Modifier and Type	Method and Description
public ChannelPipeline	addAfter(String the name of the existing handler baseName, String the name of the handler to insert after name, ChannelHandler the handler to insert after handler) Inserts a `ChannelHandler` after an existing handler of this pipeline.
public ChannelPipeline	addBefore(String the name of the existing handler baseName, String the name of the handler to insert before name, ChannelHandler the handler to insert before handler) Inserts a `ChannelHandler` before an existing handler of this pipeline.
public ChannelPipeline	addFirst(String the name of the handler to insert first name, ChannelHandler the handler to insert first handler) Inserts a `ChannelHandler` at the first position of this pipeline.
public ChannelPipeline	addFirst(ChannelHandler... the handlers to insert first handlers) Inserts `ChannelHandler`s at the first position of this pipeline.
public ChannelPipeline	addLast(String the name of the handler to append name, ChannelHandler the handler to append handler) Appends a `ChannelHandler` at the last position of this pipeline.
public ChannelPipeline	addLast(ChannelHandler... the handlers to insert last handlers) Inserts `ChannelHandler`s at the last position of this pipeline.
public Channel	Returns: the channel. `null` if this pipeline is not attached yet. channel() Returns the `Channel` that this pipeline is attached to.
public ChannelHandlerContext	Returns: the context object of the specified handler. `null` if there's no such handler in this pipeline. context(ChannelHandler handler) Returns the context object of the specified `ChannelHandler` in this pipeline.
public ChannelHandlerContext	Returns: the context object of the handler with the specified name. `null` if there's no such handler in this pipeline. context(String name) Returns the context object of the `ChannelHandler` with the specified name in this pipeline.
public ChannelHandlerContext	Returns: the context object of the handler of the specified type. `null` if there's no such handler in this pipeline. context(Class<? extends ChannelHandler> handlerType) Returns the context object of the `ChannelHandler` of the specified type in this pipeline.
public ChannelPipeline	fireChannelActive() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelActive. A `Channel` is active now, which means it is connected.
public ChannelPipeline	fireChannelExceptionCaught(Throwable cause) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelExceptionCaught. A `Channel` received an `Throwable` in one of its inbound operations.
public ChannelPipeline	fireChannelInactive() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInactive. A `Channel` is inactive now, which means it is closed.
public ChannelPipeline	fireChannelInboundEvent(Object event) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInboundEvent. A `Channel` received a custom defined inbound event.
public ChannelPipeline	fireChannelRead(Object msg) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRead. A `Channel` received a message.
public ChannelPipeline	fireChannelReadComplete() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelReadComplete. Triggers an `ChannelHandler#channelReadComplete(ChannelHandlerContext)` event to the next `ChannelHandler` in the `ChannelPipeline`.
public ChannelPipeline	fireChannelRegistered() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRegistered. A `Channel` was registered to its `EventLoop`.
public ChannelPipeline	fireChannelShutdown(ChannelShutdownDirection direction) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelShutdown. A `Channel` was shutdown in a specific direction.
public ChannelPipeline	fireChannelUnregistered() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelUnregistered. A `Channel` was unregistered from its `EventLoop`.
public ChannelPipeline	fireChannelWritabilityChanged() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelWritabilityChanged. Triggers an `ChannelHandler#channelWritabilityChanged(ChannelHandlerContext)` event to the next `ChannelHandler` in the `ChannelPipeline`.
public default ChannelHandler	Returns: the first handler. `null` if this pipeline is empty. first() Returns the first `ChannelHandler` in this pipeline.
public ChannelHandlerContext	Returns: the context of the first handler. `null` if this pipeline is empty. firstContext() Returns the context of the first `ChannelHandler` in this pipeline.
public ChannelPipeline	flush() Redeclares io.netty5.channel.ChannelOutboundInvoker.flush. Request to flush all pending messages via this ChannelOutboundInvoker.
public ChannelHandler	Returns: the handler with the specified name. `null` if there's no such handler in this pipeline. get(String name) Returns the `ChannelHandler` with the specified name in this pipeline.
public <T extends ChannelHandler> T	Returns: the handler of the specified handler type. `null` if there's no such handler in this pipeline. get(Class<T> handlerType) Returns the `ChannelHandler` of the specified type in this pipeline.
public default boolean	isEmpty() Returns `true` if this `ChannelPipeline` is empty, which means no `ChannelHandler` is present.
public default ChannelHandler	Returns: the last handler. `null` if this pipeline is empty. last() Returns the last `ChannelHandler` in this pipeline.
public ChannelHandlerContext	Returns: the context of the last handler. `null` if this pipeline is empty. lastContext() Returns the context of the last `ChannelHandler` in this pipeline.
public default List<String>	names() Returns the `List` of the handler names.
public long	Returns: the number of buffered / queued bytes. pendingOutboundBytes() The number of the outbound bytes that are buffered / queued in this `ChannelPipeline`.
public ChannelPipeline	read(ReadBufferAllocator The `ReadBufferAllocator` that should be used to allocate a `Buffer` if needed (for reading the data). readBufferAllocator) Redeclares io.netty5.channel.ChannelOutboundInvoker.read. Request to read data from the `Channel`, triggers an `ChannelHandler#channelRead(ChannelHandlerContext, Object)` event if data was read, and triggers a `channelReadComplete` event so the handler can decide to continue reading.
public ChannelPipeline	read() Redeclares io.netty5.channel.ChannelOutboundInvoker.read.
public default ChannelPipeline	remove(ChannelHandler the `ChannelHandler` to remove handler) Removes the specified `ChannelHandler` from this pipeline.
public default ChannelHandler	Returns: the removed handler remove(String the name under which the `ChannelHandler` was stored. name) Removes the `ChannelHandler` with the specified name from this pipeline.
public default < the type of the handler T extends ChannelHandler> T	Returns: the removed handler remove(Class<T> the type of the handler handlerType) Removes the `ChannelHandler` of the specified type from this pipeline.
public ChannelHandler	Returns: the removed handler removeFirst() Removes the first `ChannelHandler` in this pipeline.
public <T extends ChannelHandler> T	Returns: the removed handler removeIfExists(String the name under which the `ChannelHandler` was stored. name) Removes the `ChannelHandler` with the specified name from this pipeline if it exists.
public < the type of the handler T extends ChannelHandler> T	Returns: the removed handler or `null` if it didn't exist. removeIfExists(Class<T> the type of the handler handlerType) Removes the `ChannelHandler` of the specified type from this pipeline if it exists.
public <T extends ChannelHandler> T	Returns: the removed handler or `null` if it didn't exist. removeIfExists(ChannelHandler the `ChannelHandler` to remove handler) Removes the specified `ChannelHandler` from this pipeline if it exists
public ChannelHandler	Returns: the removed handler removeLast() Removes the last `ChannelHandler` in this pipeline.
public ChannelPipeline	Returns: itself replace(ChannelHandler the `ChannelHandler` to be replaced oldHandler, String the name under which the replacement should be added newName, ChannelHandler the `ChannelHandler` which is used as replacement newHandler) Replaces the specified `ChannelHandler` with a new handler in this pipeline.
public ChannelHandler	Returns: the removed handler replace(String the name of the `ChannelHandler` to be replaced oldName, String the name under which the replacement should be added newName, ChannelHandler the `ChannelHandler` which is used as replacement newHandler) Replaces the `ChannelHandler` of the specified name with a new handler in this pipeline.
public <T extends ChannelHandler> T	Returns: the removed handler replace(Class<T> the type of the handler to be removed oldHandlerType, String the name under which the replacement should be added newName, ChannelHandler the `ChannelHandler` which is used as replacement newHandler) Replaces the `ChannelHandler` of the specified type with a new handler in this pipeline.
public Map<String, ChannelHandler>	toMap() Converts this pipeline into an ordered `Map` whose keys are handler names and whose values are handlers.

Method Detail

addAfter back to summary

addAfter	back to summary
public ChannelPipeline addAfter(String baseName, String name, ChannelHandler handler) Inserts a `ChannelHandler` after an existing handler of this pipeline. Parameters baseName:String the name of the existing handler name:String the name of the handler to insert after handler:ChannelHandler the handler to insert after Exceptions NoSuchElementException: if there's no such entry with the specified `baseName` IllegalArgumentException: if there's an entry with the same name already in the pipeline NullPointerException: if the specified baseName or handler is `null`

public ChannelPipeline addAfter(String baseName, String name, ChannelHandler handler)

Inserts a ChannelHandler after an existing handler of this pipeline.

Parameters

baseName:String: the name of the existing handler
name:String: the name of the handler to insert after
handler:ChannelHandler: the handler to insert after

Exceptions

NoSuchElementException:: if there's no such entry with the specified baseName
IllegalArgumentException:: if there's an entry with the same name already in the pipeline
NullPointerException:: if the specified baseName or handler is null

addBefore back to summary

addBefore	back to summary
public ChannelPipeline addBefore(String baseName, String name, ChannelHandler handler) Inserts a `ChannelHandler` before an existing handler of this pipeline. Parameters baseName:String the name of the existing handler name:String the name of the handler to insert before handler:ChannelHandler the handler to insert before Exceptions NoSuchElementException: if there's no such entry with the specified `baseName` IllegalArgumentException: if there's an entry with the same name already in the pipeline NullPointerException: if the specified baseName or handler is `null`

public ChannelPipeline addBefore(String baseName, String name, ChannelHandler handler)

Inserts a ChannelHandler before an existing handler of this pipeline.

Parameters

baseName:String: the name of the existing handler
name:String: the name of the handler to insert before
handler:ChannelHandler: the handler to insert before

Exceptions

NoSuchElementException:: if there's no such entry with the specified baseName
IllegalArgumentException:: if there's an entry with the same name already in the pipeline
NullPointerException:: if the specified baseName or handler is null

addFirst back to summary

addFirst	back to summary
public ChannelPipeline addFirst(String name, ChannelHandler handler) Inserts a `ChannelHandler` at the first position of this pipeline. Parameters name:String the name of the handler to insert first handler:ChannelHandler the handler to insert first Exceptions IllegalArgumentException: if there's an entry with the same name already in the pipeline NullPointerException: if the specified handler is `null`

public ChannelPipeline addFirst(String name, ChannelHandler handler)

Inserts a ChannelHandler at the first position of this pipeline.

Parameters

name:String: the name of the handler to insert first
handler:ChannelHandler: the handler to insert first

Exceptions

IllegalArgumentException:: if there's an entry with the same name already in the pipeline
NullPointerException:: if the specified handler is null

addFirst back to summary

addFirst	back to summary
public ChannelPipeline addFirst(ChannelHandler... handlers) Inserts `ChannelHandler`s at the first position of this pipeline. `null` handlers will be skipped. Parameters handlers:ChannelHandler[] the handlers to insert first

public ChannelPipeline addFirst(ChannelHandler... handlers)

Inserts ChannelHandlers at the first position of this pipeline. null handlers will be skipped.

Parameters

handlers:ChannelHandler[]: the handlers to insert first

addLast back to summary

addLast	back to summary
public ChannelPipeline addLast(String name, ChannelHandler handler) Appends a `ChannelHandler` at the last position of this pipeline. Parameters name:String the name of the handler to append handler:ChannelHandler the handler to append Exceptions IllegalArgumentException: if there's an entry with the same name already in the pipeline NullPointerException: if the specified handler is `null`

public ChannelPipeline addLast(String name, ChannelHandler handler)

Appends a ChannelHandler at the last position of this pipeline.

Parameters

name:String: the name of the handler to append
handler:ChannelHandler: the handler to append

Exceptions

IllegalArgumentException:: if there's an entry with the same name already in the pipeline
NullPointerException:: if the specified handler is null

addLast back to summary

addLast	back to summary
public ChannelPipeline addLast(ChannelHandler... handlers) Inserts `ChannelHandler`s at the last position of this pipeline. `null` handlers will be skipped. Parameters handlers:ChannelHandler[] the handlers to insert last

public ChannelPipeline addLast(ChannelHandler... handlers)

Inserts ChannelHandlers at the last position of this pipeline. null handlers will be skipped.

Parameters

handlers:ChannelHandler[]: the handlers to insert last

channel back to summary

channel	back to summary
public Channel channel() Returns the `Channel` that this pipeline is attached to. Returns:Channel the channel. `null` if this pipeline is not attached yet.

public Channel channel()

Returns the Channel that this pipeline is attached to.

Returns:Channel: the channel. null if this pipeline is not attached yet.

context back to summary

context	back to summary
public ChannelHandlerContext context(ChannelHandler handler) Returns the context object of the specified `ChannelHandler` in this pipeline. Returns:ChannelHandlerContext the context object of the specified handler. `null` if there's no such handler in this pipeline.

public ChannelHandlerContext context(ChannelHandler handler)

Returns the context object of the specified ChannelHandler in this pipeline.

Returns:ChannelHandlerContext: the context object of the specified handler. null if there's no such handler in this pipeline.

context back to summary

context	back to summary
public ChannelHandlerContext context(String name) Returns the context object of the `ChannelHandler` with the specified name in this pipeline. Returns:ChannelHandlerContext the context object of the handler with the specified name. `null` if there's no such handler in this pipeline.

public ChannelHandlerContext context(String name)

Returns the context object of the ChannelHandler with the specified name in this pipeline.

Returns:ChannelHandlerContext: the context object of the handler with the specified name. null if there's no such handler in this pipeline.

context back to summary

context	back to summary
public ChannelHandlerContext context(Class<? extends ChannelHandler> handlerType) Returns the context object of the `ChannelHandler` of the specified type in this pipeline. Returns:ChannelHandlerContext the context object of the handler of the specified type. `null` if there's no such handler in this pipeline.

public ChannelHandlerContext context(Class<? extends ChannelHandler> handlerType)

Returns the context object of the ChannelHandler of the specified type in this pipeline.

Returns:ChannelHandlerContext: the context object of the handler of the specified type. null if there's no such handler in this pipeline.

fireChannelActive back to summary

fireChannelActive	back to summary
public ChannelPipeline fireChannelActive() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelActive. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelActive. A `Channel` is active now, which means it is connected. This will result in having the `ChannelHandler#channelActive(ChannelHandlerContext)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelActive()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelActive.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelActive.

A Channel is active now, which means it is connected. This will result in having the ChannelHandler#channelActive(ChannelHandlerContext) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelExceptionCaught back to summary

fireChannelExceptionCaught	back to summary
public ChannelPipeline fireChannelExceptionCaught(Throwable cause) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelExceptionCaught. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelExceptionCaught. A `Channel` received an `Throwable` in one of its inbound operations. This will result in having the `ChannelHandler#channelExceptionCaught(ChannelHandlerContext, Throwable)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelExceptionCaught(Throwable cause)

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelExceptionCaught.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelExceptionCaught.

A Channel received an Throwable in one of its inbound operations. This will result in having the ChannelHandler#channelExceptionCaught(ChannelHandlerContext, Throwable) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelInactive back to summary

fireChannelInactive	back to summary
public ChannelPipeline fireChannelInactive() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInactive. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelInactive. A `Channel` is inactive now, which means it is closed. This will result in having the `ChannelHandler#channelInactive(ChannelHandlerContext)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelInactive()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInactive.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelInactive.

A Channel is inactive now, which means it is closed. This will result in having the ChannelHandler#channelInactive(ChannelHandlerContext) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelInboundEvent back to summary

fireChannelInboundEvent	back to summary
public ChannelPipeline fireChannelInboundEvent(Object event) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInboundEvent. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelInboundEvent. A `Channel` received a custom defined inbound event. This will result in having the `ChannelHandler#channelInboundEvent(ChannelHandlerContext, Object)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelInboundEvent(Object event)

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelInboundEvent.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelInboundEvent.

A Channel received a custom defined inbound event. This will result in having the ChannelHandler#channelInboundEvent(ChannelHandlerContext, Object) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelRead back to summary

fireChannelRead	back to summary
public ChannelPipeline fireChannelRead(Object msg) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRead. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelRead. A `Channel` received a message. This will result in having the `ChannelHandler#channelRead(ChannelHandlerContext, Object)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelRead(Object msg)

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRead.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelRead.

A Channel received a message. This will result in having the ChannelHandler#channelRead(ChannelHandlerContext, Object) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelReadComplete back to summary

fireChannelReadComplete	back to summary
public ChannelPipeline fireChannelReadComplete() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelReadComplete. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelReadComplete. Triggers an `ChannelHandler#channelReadComplete(ChannelHandlerContext)` event to the next `ChannelHandler` in the `ChannelPipeline`. Annotations @Override

public ChannelPipeline fireChannelReadComplete()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelReadComplete.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelReadComplete.

Triggers an ChannelHandler#channelReadComplete(ChannelHandlerContext) event to the next ChannelHandler in the ChannelPipeline.

Annotations

@Override

fireChannelRegistered back to summary

fireChannelRegistered	back to summary
public ChannelPipeline fireChannelRegistered() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRegistered. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelRegistered. A `Channel` was registered to its `EventLoop`. This will result in having the `ChannelHandler#channelRegistered(ChannelHandlerContext)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelRegistered()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelRegistered.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelRegistered.

A Channel was registered to its EventLoop. This will result in having the ChannelHandler#channelRegistered(ChannelHandlerContext) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelShutdown back to summary

fireChannelShutdown	back to summary
public ChannelPipeline fireChannelShutdown(ChannelShutdownDirection direction) Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelShutdown. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelShutdown. A `Channel` was shutdown in a specific direction. This will result in having the `ChannelHandler#channelShutdown(ChannelHandlerContext, ChannelShutdownDirection)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelShutdown(ChannelShutdownDirection direction)

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelShutdown.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelShutdown.

A Channel was shutdown in a specific direction. This will result in having the ChannelHandler#channelShutdown(ChannelHandlerContext, ChannelShutdownDirection) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelUnregistered back to summary

fireChannelUnregistered	back to summary
public ChannelPipeline fireChannelUnregistered() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelUnregistered. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelUnregistered. A `Channel` was unregistered from its `EventLoop`. This will result in having the `ChannelHandler#channelUnregistered(ChannelHandlerContext)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Annotations @Override

public ChannelPipeline fireChannelUnregistered()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelUnregistered.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelUnregistered.

A Channel was unregistered from its EventLoop. This will result in having the ChannelHandler#channelUnregistered(ChannelHandlerContext) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Annotations

@Override

fireChannelWritabilityChanged back to summary

fireChannelWritabilityChanged	back to summary
public ChannelPipeline fireChannelWritabilityChanged() Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelWritabilityChanged. Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelWritabilityChanged. Triggers an `ChannelHandler#channelWritabilityChanged(ChannelHandlerContext)` event to the next `ChannelHandler` in the `ChannelPipeline`. Annotations @Override

public ChannelPipeline fireChannelWritabilityChanged()

Redeclares io.netty5.channel.ChannelInboundInvoker.fireChannelWritabilityChanged.

Doc from io.netty5.channel.ChannelInboundInvoker.fireChannelWritabilityChanged.

Triggers an ChannelHandler#channelWritabilityChanged(ChannelHandlerContext) event to the next ChannelHandler in the ChannelPipeline.

Annotations

@Override

first back to summary

first	back to summary
public default ChannelHandler first() Returns the first `ChannelHandler` in this pipeline. Returns:ChannelHandler the first handler. `null` if this pipeline is empty.

public default ChannelHandler first()

Returns the first ChannelHandler in this pipeline.

Returns:ChannelHandler: the first handler. null if this pipeline is empty.

firstContext back to summary

firstContext	back to summary
public ChannelHandlerContext firstContext() Returns the context of the first `ChannelHandler` in this pipeline. Returns:ChannelHandlerContext the context of the first handler. `null` if this pipeline is empty.

public ChannelHandlerContext firstContext()

Returns the context of the first ChannelHandler in this pipeline.

Returns:ChannelHandlerContext: the context of the first handler. null if this pipeline is empty.

flush	back to summary
public ChannelPipeline flush() Redeclares io.netty5.channel.ChannelOutboundInvoker.flush. Doc from io.netty5.channel.ChannelOutboundInvoker.flush. Request to flush all pending messages via this ChannelOutboundInvoker. Annotations @Override

flush

back to summary

public ChannelPipeline flush()

Redeclares io.netty5.channel.ChannelOutboundInvoker.flush.

Doc from io.netty5.channel.ChannelOutboundInvoker.flush.

Request to flush all pending messages via this ChannelOutboundInvoker.

Annotations

@Override

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public ChannelHandler get(String name) Returns the `ChannelHandler` with the specified name in this pipeline. Returns:ChannelHandler the handler with the specified name. `null` if there's no such handler in this pipeline.

public ChannelHandler get(String name)

Returns the ChannelHandler with the specified name in this pipeline.

Returns:ChannelHandler: the handler with the specified name. null if there's no such handler in this pipeline.

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public <T extends ChannelHandler> T get(Class<T> handlerType) Returns the `ChannelHandler` of the specified type in this pipeline. Returns:T the handler of the specified handler type. `null` if there's no such handler in this pipeline.

public <T extends ChannelHandler> T get(Class<T> handlerType)

Returns the ChannelHandler of the specified type in this pipeline.

Returns:T: the handler of the specified handler type. null if there's no such handler in this pipeline.

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public default boolean isEmpty() Returns `true` if this `ChannelPipeline` is empty, which means no `ChannelHandler` is present.

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public default ChannelHandler last() Returns the last `ChannelHandler` in this pipeline. Returns:ChannelHandler the last handler. `null` if this pipeline is empty.

public default ChannelHandler last()

Returns the last ChannelHandler in this pipeline.

Returns:ChannelHandler: the last handler. null if this pipeline is empty.

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public ChannelHandlerContext lastContext() Returns the context of the last `ChannelHandler` in this pipeline. Returns:ChannelHandlerContext the context of the last handler. `null` if this pipeline is empty.

public ChannelHandlerContext lastContext()

Returns the context of the last ChannelHandler in this pipeline.

Returns:ChannelHandlerContext: the context of the last handler. null if this pipeline is empty.

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public default List<String> names() Returns the `List` of the handler names.

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public long pendingOutboundBytes() The number of the outbound bytes that are buffered / queued in this `ChannelPipeline`. This number will affect the writability of the `Channel` together the buffered / queued bytes in the `Channel` itself. Returns:long the number of buffered / queued bytes.

public long pendingOutboundBytes()

The number of the outbound bytes that are buffered / queued in this ChannelPipeline. This number will affect the writability of the Channel together the buffered / queued bytes in the Channel itself.

Returns:long: the number of buffered / queued bytes.

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public ChannelPipeline read(ReadBufferAllocator readBufferAllocator) Redeclares io.netty5.channel.ChannelOutboundInvoker.read. Doc from io.netty5.channel.ChannelOutboundInvoker.read. Request to read data from the `Channel`, triggers an `ChannelHandler#channelRead(ChannelHandlerContext, Object)` event if data was read, and triggers a `channelReadComplete` event so the handler can decide to continue reading. If there's a pending read operation already, this method does nothing. This will result in having the `ChannelHandler#read(ChannelHandlerContext, ReadBufferAllocator)` method called of the next `ChannelHandler` contained in the `ChannelPipeline` of the `Channel`. Parameters readBufferAllocator:ReadBufferAllocator The `ReadBufferAllocator` that should be used to allocate a `Buffer` if needed (for reading the data). Annotations @Override

public ChannelPipeline read(ReadBufferAllocator readBufferAllocator)

Redeclares io.netty5.channel.ChannelOutboundInvoker.read.

Doc from io.netty5.channel.ChannelOutboundInvoker.read.

Request to read data from the Channel, triggers an ChannelHandler#channelRead(ChannelHandlerContext, Object) event if data was read, and triggers a channelReadComplete event so the handler can decide to continue reading. If there's a pending read operation already, this method does nothing.

This will result in having the ChannelHandler#read(ChannelHandlerContext, ReadBufferAllocator) method called of the next ChannelHandler contained in the ChannelPipeline of the Channel.

Parameters

readBufferAllocator:ReadBufferAllocator: The ReadBufferAllocator that should be used to allocate a Buffer if needed (for reading the data).

Annotations

@Override

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public ChannelPipeline read() Redeclares io.netty5.channel.ChannelOutboundInvoker.read. Annotations @Override

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public ChannelPipeline read()

Redeclares io.netty5.channel.ChannelOutboundInvoker.read.

Annotations

@Override

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public default ChannelPipeline remove(ChannelHandler handler) Removes the specified `ChannelHandler` from this pipeline. Parameters handler:ChannelHandler the `ChannelHandler` to remove Exceptions NoSuchElementException: if there's no such handler in this pipeline NullPointerException: if the specified handler is `null`

public default ChannelPipeline remove(ChannelHandler handler)

Removes the specified ChannelHandler from this pipeline.

Parameters

handler:ChannelHandler: the ChannelHandler to remove

Exceptions

NoSuchElementException:: if there's no such handler in this pipeline
NullPointerException:: if the specified handler is null

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public default ChannelHandler remove(String name) Removes the `ChannelHandler` with the specified name from this pipeline. Parameters name:String the name under which the `ChannelHandler` was stored. Returns:ChannelHandler the removed handler Exceptions NoSuchElementException: if there's no such handler with the specified name in this pipeline NullPointerException: if the specified name is `null`

public default ChannelHandler remove(String name)

Removes the ChannelHandler with the specified name from this pipeline.

Parameters

name:String: the name under which the ChannelHandler was stored.

Returns:ChannelHandler

the removed handler

Exceptions

NoSuchElementException:: if there's no such handler with the specified name in this pipeline
NullPointerException:: if the specified name is null

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public default <T extends ChannelHandler> T remove(Class<T> handlerType) Removes the `ChannelHandler` of the specified type from this pipeline. Parameters <T> the type of the handler handlerType:Class<T> the type of the handler Returns:T the removed handler Exceptions NoSuchElementException: if there's no such handler of the specified type in this pipeline NullPointerException: if the specified handler type is `null`

public default <T extends ChannelHandler> T remove(Class<T> handlerType)

Removes the ChannelHandler of the specified type from this pipeline.

Parameters

<T>: the type of the handler
handlerType:Class<T>: the type of the handler

Returns:T

the removed handler

Exceptions

NoSuchElementException:: if there's no such handler of the specified type in this pipeline
NullPointerException:: if the specified handler type is null

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public ChannelHandler removeFirst() Removes the first `ChannelHandler` in this pipeline. Returns:ChannelHandler the removed handler Exceptions NoSuchElementException: if this pipeline is empty

public ChannelHandler removeFirst()

Removes the first ChannelHandler in this pipeline.

Returns:ChannelHandler

the removed handler

Exceptions

NoSuchElementException:: if this pipeline is empty

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public <T extends ChannelHandler> T removeIfExists(String name) Removes the `ChannelHandler` with the specified name from this pipeline if it exists. Parameters name:String the name under which the `ChannelHandler` was stored. Returns:T the removed handler Exceptions NoSuchElementException: if there's no such handler with the specified name in this pipeline NullPointerException: if the specified name is `null`

public <T extends ChannelHandler> T removeIfExists(String name)

Removes the ChannelHandler with the specified name from this pipeline if it exists.

Parameters

name:String: the name under which the ChannelHandler was stored.

Returns:T

the removed handler

Exceptions

NoSuchElementException:: if there's no such handler with the specified name in this pipeline
NullPointerException:: if the specified name is null

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public <T extends ChannelHandler> T removeIfExists(Class<T> handlerType) Removes the `ChannelHandler` of the specified type from this pipeline if it exists. Parameters <T> the type of the handler handlerType:Class<T> the type of the handler Returns:T the removed handler or `null` if it didn't exist. Exceptions NullPointerException: if the specified handler type is `null`

public <T extends ChannelHandler> T removeIfExists(Class<T> handlerType)

Removes the ChannelHandler of the specified type from this pipeline if it exists.

Parameters

<T>: the type of the handler
handlerType:Class<T>: the type of the handler

Returns:T

the removed handler or null if it didn't exist.

Exceptions

NullPointerException:: if the specified handler type is null

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public <T extends ChannelHandler> T removeIfExists(ChannelHandler handler) Removes the specified `ChannelHandler` from this pipeline if it exists Parameters handler:ChannelHandler the `ChannelHandler` to remove Returns:T the removed handler or `null` if it didn't exist. Exceptions NullPointerException: if the specified handler is `null`

public <T extends ChannelHandler> T removeIfExists(ChannelHandler handler)

Removes the specified ChannelHandler from this pipeline if it exists

Parameters

handler:ChannelHandler: the ChannelHandler to remove

Returns:T

the removed handler or null if it didn't exist.

Exceptions

NullPointerException:: if the specified handler is null

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public ChannelHandler removeLast() Removes the last `ChannelHandler` in this pipeline. Returns:ChannelHandler the removed handler Exceptions NoSuchElementException: if this pipeline is empty

public ChannelHandler removeLast()

Removes the last ChannelHandler in this pipeline.

Returns:ChannelHandler

the removed handler

Exceptions

NoSuchElementException:: if this pipeline is empty

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public ChannelPipeline replace(ChannelHandler oldHandler, String newName, ChannelHandler newHandler) Replaces the specified `ChannelHandler` with a new handler in this pipeline. Parameters oldHandler:ChannelHandler the `ChannelHandler` to be replaced newName:String the name under which the replacement should be added newHandler:ChannelHandler the `ChannelHandler` which is used as replacement Returns:ChannelPipeline itself Exceptions NoSuchElementException: if the specified old handler does not exist in this pipeline IllegalArgumentException: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced NullPointerException: if the specified old handler or new handler is `null`

public ChannelPipeline replace(ChannelHandler oldHandler, String newName, ChannelHandler newHandler)

Replaces the specified ChannelHandler with a new handler in this pipeline.

Parameters

oldHandler:ChannelHandler: the ChannelHandler to be replaced
newName:String: the name under which the replacement should be added
newHandler:ChannelHandler: the ChannelHandler which is used as replacement

Returns:ChannelPipeline

itself

Exceptions

NoSuchElementException:: if the specified old handler does not exist in this pipeline
IllegalArgumentException:: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced
NullPointerException:: if the specified old handler or new handler is null

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public ChannelHandler replace(String oldName, String newName, ChannelHandler newHandler) Replaces the `ChannelHandler` of the specified name with a new handler in this pipeline. Parameters oldName:String the name of the `ChannelHandler` to be replaced newName:String the name under which the replacement should be added newHandler:ChannelHandler the `ChannelHandler` which is used as replacement Returns:ChannelHandler the removed handler Exceptions NoSuchElementException: if the handler with the specified old name does not exist in this pipeline IllegalArgumentException: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced NullPointerException: if the specified old handler or new handler is `null`

public ChannelHandler replace(String oldName, String newName, ChannelHandler newHandler)

Replaces the ChannelHandler of the specified name with a new handler in this pipeline.

Parameters

oldName:String: the name of the ChannelHandler to be replaced
newName:String: the name under which the replacement should be added
newHandler:ChannelHandler: the ChannelHandler which is used as replacement

Returns:ChannelHandler

the removed handler

Exceptions

NoSuchElementException:: if the handler with the specified old name does not exist in this pipeline
IllegalArgumentException:: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced
NullPointerException:: if the specified old handler or new handler is null

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public <T extends ChannelHandler> T replace(Class<T> oldHandlerType, String newName, ChannelHandler newHandler) Replaces the `ChannelHandler` of the specified type with a new handler in this pipeline. Parameters oldHandlerType:Class<T> the type of the handler to be removed newName:String the name under which the replacement should be added newHandler:ChannelHandler the `ChannelHandler` which is used as replacement Returns:T the removed handler Exceptions NoSuchElementException: if the handler of the specified old handler type does not exist in this pipeline IllegalArgumentException: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced NullPointerException: if the specified old handler or new handler is `null`

public <T extends ChannelHandler> T replace(Class<T> oldHandlerType, String newName, ChannelHandler newHandler)

Replaces the ChannelHandler of the specified type with a new handler in this pipeline.

Parameters

oldHandlerType:Class<T>: the type of the handler to be removed
newName:String: the name under which the replacement should be added
newHandler:ChannelHandler: the ChannelHandler which is used as replacement

Returns:T

the removed handler

Exceptions

NoSuchElementException:: if the handler of the specified old handler type does not exist in this pipeline
IllegalArgumentException:: if a handler with the specified new name already exists in this pipeline, except for the handler to be replaced
NullPointerException:: if the specified old handler or new handler is null

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public Map<String, ChannelHandler> toMap() Converts this pipeline into an ordered `Map` whose keys are handler names and whose values are handlers.

public Interface ChannelPipeline

Creation of a pipeline

How an event flows in a pipeline

Forwarding an event to the next handler

Building a pipeline

Thread safety

Method Summary

Method Detail