org.apache.http.nio.protocol.HttpAsyncClientExchangeHandler Maven / Gradle / Ivy
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
*
* Individual {@code HttpAsyncClientExchangeHandler} are expected to make use of
* a {@link org.apache.http.protocol.HttpProcessor} to generate mandatory protocol
* headers for all outgoing messages and apply common, cross-cutting message
* transformations to all incoming and outgoing messages.
* {@code HttpAsyncClientExchangeHandler}s can delegate implementation
* of application specific content generation and processing to
* a {@link HttpAsyncRequestProducer} and a {@link HttpAsyncResponseConsumer}.
*
* @since 4.3
*/
public interface HttpAsyncClientExchangeHandler extends Closeable, Cancellable {
/**
* Invoked to generate a HTTP request message head. The message is expected
* to implement the {@link org.apache.http.HttpEntityEnclosingRequest} interface if it is
* to enclose a content entity. The {@link #produceContent(ContentEncoder,
* IOControl)} method will not be invoked if
* {@link org.apache.http.HttpEntityEnclosingRequest#getEntity()} returns
* {@code null}.
*
* @return HTTP request message.
* @throws HttpException in case of HTTP protocol violation
* @throws IOException in case of an I/O error
*/
HttpRequest generateRequest() throws IOException, HttpException;
/**
* Invoked to write out a chunk of content to the {@link ContentEncoder}.
* The {@link IOControl} interface can be used to suspend output event
* notifications if the producer is temporarily unable to produce more content.
*
* When all content is finished, the producer MUST call
* {@link ContentEncoder#complete()}. Failure to do so may cause the entity
* to be incorrectly delimited.
*
* Please note that the {@link ContentEncoder} object is not thread-safe and
* should only be used within the context of this method call.
* The {@link IOControl} object can be shared and used on other thread
* to resume output event notifications when more content is made available.
*
* @param encoder content encoder.
* @param ioControl I/O control of the underlying connection.
* @throws IOException in case of an I/O error
*/
void produceContent(ContentEncoder encoder, IOControl ioControl) throws IOException;
/**
* Invoked to signal that the request has been fully written out.
*/
void requestCompleted();
/**
* Invoked when a HTTP response message is received. Please note
* that the {@link #consumeContent(ContentDecoder, IOControl)} method
* will be invoked only if the response messages has a content entity
* enclosed.
*
* @param response HTTP response message.
* @throws HttpException in case of HTTP protocol violation
* @throws IOException in case of an I/O error
*/
void responseReceived(HttpResponse response) throws IOException, HttpException;
/**
* Invoked to process a chunk of content from the {@link ContentDecoder}.
* The {@link IOControl} interface can be used to suspend input event
* notifications if the consumer is temporarily unable to process content.
*
* The consumer can use the {@link ContentDecoder#isCompleted()} method
* to find out whether or not the message content has been fully consumed.
*
* Please note that the {@link ContentDecoder} object is not thread-safe and
* should only be used within the context of this method call.
* The {@link IOControl} object can be shared and used on other thread
* to resume input event notifications when the consumer is capable of
* processing more content.
*
* @param decoder content decoder.
* @param ioControl I/O control of the underlying connection.
* @throws IOException in case of an I/O error
*/
void consumeContent(ContentDecoder decoder, IOControl ioControl) throws IOException;
/**
* Invoked to signal that the response has been fully processed.
*/
void responseCompleted() throws IOException, HttpException;
/**
* Invoked to signal that the connection has been terminated prematurely
* by the opposite end.
*/
void inputTerminated();
/**
* Invoked to signal that the response processing terminated abnormally.
*
* @param ex exception
*/
void failed(Exception ex);
/**
* Determines whether or not the response processing completed.
*/
boolean isDone();
}