org.microbean.jersey.netty

Class AbstractContainerRequestDecoder<T,H extends T,D extends T>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

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

org.microbean.jersey.netty.AbstractContainerRequestDecoder<T,H,D>

Type Parameters:

T - the common supertype of messages that can be decoded

H - the type of "headers" messages

D - the type of "data" messages

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:

Http2StreamFrameToContainerRequestDecoder, HttpObjectToContainerRequestDecoder

public abstract class AbstractContainerRequestDecoder<T,H extends T,D extends T>
extends MessageToMessageDecoder<T>

A MessageToMessageDecoder that decodes messages of a specific type into ContainerRequests.

Instances of this class are normally followed in a ChannelPipeline by instances of the AbstractContainerRequestHandlingResponseWriter class.

Author:

Laird Nelson

See Also:

decode(ChannelHandlerContext, Object, List), MessageToMessageDecoder, ContainerRequest, AbstractContainerRequestHandlingResponseWriter

Nested Class Summary

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

ChannelHandler.Sharable

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractContainerRequestDecoder(URI baseUri, Class<H> headersClass, Class<D> dataClass) Deprecated. Please use the AbstractContainerRequestDecoder(URI, Configuration, Class, Class) constructor instead.
protected	AbstractContainerRequestDecoder(URI baseUri, Configuration configuration, Class<H> headersClass, Class<D> dataClass) Creates a new AbstractContainerRequestDecoder implementation.
protected	AbstractContainerRequestDecoder(URI baseUri, Supplier<? extends Configuration> configurationSupplier, Class<H> headersClass, Class<D> dataClass) Creates a new AbstractContainerRequestDecoder implementation.

Method Summary

Modifier and Type	Method and Description
boolean	acceptInboundMessage(Object message) Returns true if the supplied message is an instance of either the headers type or data type supplied at construction time, and false in all other cases.
void	channelReadComplete(ChannelHandlerContext channelHandlerContext) Overrides the ChannelInboundHandlerAdapter.channelReadComplete(ChannelHandlerContext) method to request a read when necessary, taking the auto-read status of the associated Channel into account.
protected PropertiesDelegate	createPropertiesDelegate(H message) Creates and returns a PropertiesDelegate appropriate for the supplied message, which is guaranteed to be a "headers" message.
protected SecurityContext	createSecurityContext(H message) Creates and returns a SecurityContext appropriate for the supplied message, which is guaranteed to be a "headers" message.
protected TerminableByteBufInputStream	createTerminableByteBufInputStream(ByteBufAllocator byteBufAllocator) Creates and returns a new TerminableByteBufInputStream.
protected void	decode(ChannelHandlerContext channelHandlerContext, T message, List<Object> out) Decodes the supplied message into a ContainerRequest and adds it to the supplied out List.
protected ByteBuf	getContent(D message) Extracts any content from the supplied "data" message as a ByteBuf, or returns null if there is no such content.
protected abstract String	getMethod(H message) Extracts and returns a String representing a request method from the supplied message, which is guaranteed to be a "headers" message.
protected abstract String	getRequestUriString(H message) Extracts and returns a String representing a request URI from the supplied message, which is guaranteed to be a "headers" message.
protected void	installMessage(ChannelHandlerContext channelHandlerContext, H message, ContainerRequest containerRequest) Installs the supplied message into the supplied ContainerRequest in some way.
protected boolean	isData(T message) Returns true if the supplied message represents a "data" message (as distinguished from a "headers" message).
protected boolean	isHeaders(T message) Returns true if the supplied message represents a "headers" message (as distinguished from a "data" message).
protected abstract boolean	isLast(T message) Returns true if there will be no further message components in an overall larger message after the supplied one.

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

channelRead

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

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

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, 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

handlerAdded, handlerRemoved

Constructor Detail

AbstractContainerRequestDecoder

@Deprecated
protected AbstractContainerRequestDecoder(URI baseUri,
                                                      Class<H> headersClass,
                                                      Class<D> dataClass)

Deprecated. Please use the AbstractContainerRequestDecoder(URI, Configuration, Class, Class) constructor instead.

Creates a new AbstractContainerRequestDecoder implementation.

Parameters:

baseUri - the base URI against which relative request URIs will be resolved; may be null in which case the return value of URI.create("/") will be used instead

headersClass - the type representing a "headers" message; must not be null

dataClass - the type representing a "data" message; must not be null

Throws:

NullPointerException - if either headersClass or dataClass is null

See Also:

AbstractContainerRequestDecoder(URI, Configuration, Class, Class)

AbstractContainerRequestDecoder

protected AbstractContainerRequestDecoder(URI baseUri,
                                          Configuration configuration,
                                          Class<H> headersClass,
                                          Class<D> dataClass)

Creates a new AbstractContainerRequestDecoder implementation.

Parameters:

baseUri - the base URI against which relative request URIs will be resolved; may be null in which case the return value of URI.create("/") will be used instead

configuration - a Configuration describing how the container is configured; may be null

headersClass - the type representing a "headers" message; must not be null

dataClass - the type representing a "data" message; must not be null

Throws:

NullPointerException - if either headersClass or dataClass is null

AbstractContainerRequestDecoder

protected AbstractContainerRequestDecoder(URI baseUri,
                                          Supplier<? extends Configuration> configurationSupplier,
                                          Class<H> headersClass,
                                          Class<D> dataClass)

Creates a new AbstractContainerRequestDecoder implementation.

Parameters:

baseUri - the base URI against which relative request URIs will be resolved; may be null in which case the return value of URI.create("/") will be used instead

configurationSupplier - a Supplier of Configuration instances describing how the container is configured; may be null

headersClass - the type representing a "headers" message; must not be null

dataClass - the type representing a "data" message; must not be null

Throws:

NullPointerException - if either headersClass or dataClass is null

Method Detail

channelReadComplete

public void channelReadComplete(ChannelHandlerContext channelHandlerContext)
                         throws Exception

Overrides the ChannelInboundHandlerAdapter.channelReadComplete(ChannelHandlerContext) method to request a read when necessary, taking the auto-read status of the associated Channel into account.

Specified by:

channelReadComplete in interface ChannelInboundHandler

Overrides:

channelReadComplete in class ChannelInboundHandlerAdapter

Parameters:

channelHandlerContext - the ChannelHandlerContext in effect; must not be null

Throws:

NullPointerException - if channelHandlerContext is null

Exception

See Also:

ChannelConfig.isAutoRead(), ChannelInboundHandlerAdapter.channelReadComplete(ChannelHandlerContext)

acceptInboundMessage

public boolean acceptInboundMessage(Object message)

Returns true if the supplied message is an instance of either the headers type or data type supplied at construction time, and false in all other cases.

Overrides:

acceptInboundMessage in class MessageToMessageDecoder<T>

Parameters:

message - the message to interrogate; may be null in which case false will be returned

Returns:

true if the supplied message is an instance of either the headers type or data type supplied at construction time; false in all other cases

See Also:

AbstractContainerRequestDecoder(URI, Class, Class)

isHeaders

protected boolean isHeaders(T message)

Returns true if the supplied message represents a "headers" message (as distinguished from a "data" message).

Parameters:

message - the message to interrogate; will not be null

Returns:

true if the supplied message represents a "headers" message; false otherwise

See Also:

isData(Object)

getRequestUriString

protected abstract String getRequestUriString(H message)

Extracts and returns a String representing a request URI from the supplied message, which is guaranteed to be a "headers" message.

Implementations of this method may return null but normally will not.

Parameters:

message - the message to interrogate; will not be null

Returns:

a String representing a request URI from the supplied message, or null

getMethod

protected abstract String getMethod(H message)

Extracts and returns a String representing a request method from the supplied message, which is guaranteed to be a "headers" message.

Implementations of this method may return null but normally will not.

Parameters:

message - the message to interrogate; will not be null

Returns:

a String representing a request method from the supplied message, or null

createSecurityContext

protected SecurityContext createSecurityContext(H message)

Creates and returns a SecurityContext appropriate for the supplied message, which is guaranteed to be a "headers" message.

Implementations of this method must not return null.

Parameters:

message - the "headers" message for which a new SecurityContext is to be returned; will not be null

Returns:

a new, non-null SecurityContext

createPropertiesDelegate

protected PropertiesDelegate createPropertiesDelegate(H message)

Creates and returns a PropertiesDelegate appropriate for the supplied message, which is guaranteed to be a "headers" message.

Implementations of this method must not return null.

Parameters:

message - the "headers" message for which a new PropertiesDelegate is to be returned; will not be null

Returns:

a new, non-null PropertiesDelegate

installMessage

protected void installMessage(ChannelHandlerContext channelHandlerContext,
                              H message,
                              ContainerRequest containerRequest)

Installs the supplied message into the supplied ContainerRequest in some way.

This implementation calls ContainerRequest.setProperty(String, Object) with the fully-qualified class name of the headers class supplied at construction time as the key, and the supplied message as the value.

Parameters:

channelHandlerContext - the ChannelHandlerContext in effect; will not be null; supplied for convenience; overrides may (and often do) ignore this parameter

message - the message to install; will not be null and is guaranteed to be a "headers" message

containerRequest - the just-constructed ContainerRequest into which to install the supplied message; will not be null

isData

protected boolean isData(T message)

Returns true if the supplied message represents a "data" message (as distinguished from a "headers" message).

Parameters:

message - the message to interrogate; will not be null

Returns:

true if the supplied message represents a "data" message; false otherwise

See Also:

isHeaders(Object)

getContent

protected ByteBuf getContent(D message)

Extracts any content from the supplied "data" message as a ByteBuf, or returns null if there is no such content.

Parameters:

message - the "data" message from which a ByteBuf is to be extracted; will not be null

Returns:

a ByteBuf representing the message's content, or null

isLast

protected abstract boolean isLast(T message)

Returns true if there will be no further message components in an overall larger message after the supplied one.

Parameters:

message - the message component to interrogate; will not be null; may be either a "headers" or "data" message component

Returns:

true if and only if there will be no further message components to come

decode

protected final void decode(ChannelHandlerContext channelHandlerContext,
                            T message,
                            List<Object> out)

Decodes the supplied message into a ContainerRequest and adds it to the supplied out List.

Specified by:

decode in class MessageToMessageDecoder<T>

Parameters:

channelHandlerContext - the ChannelHandlerContext in effect; must not be null

message - the message to decode; must not be null and must be acceptable

out - a List of Objects that result from decoding the supplied message; must not be null and must be mutable

Throws:

NullPointerException - if channelHandlerContext or out is null

IllegalArgumentException - if message is null or otherwise unacceptable

IllegalStateException - if there is an internal problem with state management

createTerminableByteBufInputStream

protected TerminableByteBufInputStream createTerminableByteBufInputStream(ByteBufAllocator byteBufAllocator)

Creates and returns a new TerminableByteBufInputStream.

Parameters:

byteBufAllocator - a ByteBufAllocator that may be used or ignored; will not be null

Returns:

a new, non-null TerminableByteBufInputStream