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package org.apache.http.nio.protocol;

import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.concurrent.Cancellable;

HttpAsyncExchange represents a server-side HTTP message exchange where an HTTP response can be deferred without blocking the I/O event thread and triggered asynchronously at a later point of later time. 
Since:
4.2/**
 * {@code HttpAsyncExchange} represents a server-side HTTP message exchange
 * where an HTTP response can be deferred without blocking the I/O event thread
 * and triggered asynchronously at a later point of later time.
 *
 * @since 4.2
 */
public interface HttpAsyncExchange {

    
Returns the received HTTP request message.
Returns:
received HTTP request message./**
     * Returns the received HTTP request message.
     *
     * @return received HTTP request message.
     */
    HttpRequest getRequest();

    
Returns the default HTTP response message. Once ready the response message can submitted using submitResponse() method. 
Returns:
default HTTP response message./**
     * Returns the default HTTP response message. Once ready the response
     * message can submitted using {@link #submitResponse()} method.
     *
     * @return default HTTP response message.
     */
    HttpResponse getResponse();

    
Submits the default HTTP response and completed the message exchange. If the response encloses an HttpEntity instance the entity is also expected to implement the HttpAsyncContentProducer interface for efficient content streaming to a non-blocking HTTP connection. 
Throws:
IllegalStateException – if a response has already been submitted./**
     * Submits the default HTTP response and completed the message exchange.
     * If the response encloses an {@link org.apache.http.HttpEntity} instance
     * the entity is also expected to implement the
     * {@link org.apache.http.nio.entity.HttpAsyncContentProducer }
     * interface for efficient content streaming to a non-blocking HTTP
     * connection.
     *
     * @throws IllegalStateException if a response has already been submitted.
     */
    void submitResponse();

    
Submits an HTTP response using a custom HttpAsyncResponseProducer. 
Throws:
IllegalStateException – if a response has already been submitted./**
     * Submits an HTTP response using a custom
     * {@link HttpAsyncResponseProducer}.
     *
     * @throws IllegalStateException if a response has already been submitted.
     */
    void submitResponse(HttpAsyncResponseProducer responseProducer);

    
Determines whether or not the message exchange has been completed.
Returns:
true if the message exchange has been completed, false otherwise./**
     * Determines whether or not the message exchange has been completed.
     *
     * @return {@code true} if the message exchange has been completed,
     * {@code false} otherwise.
     */
    boolean isCompleted();

    
Sets Cancellable callback to be invoked in case the underlying connection times out or gets terminated prematurely by the client. This callback can be used to cancel a long running response generating process if a response is no longer needed. /**
     * Sets {@link Cancellable} callback to be invoked in case the underlying
     * connection times out or gets terminated prematurely by the client. This
     * callback can be used to cancel a long running response generating
     * process if a response is no longer needed.
     */
    void setCallback(Cancellable cancellable);

    
Sets timeout for this message exchange.
/**
     * Sets timeout for this message exchange.
     */
    void setTimeout(int timeout);

    
Returns timeout for this message exchange.
/**
     * Returns timeout for this message exchange.
     */
    int getTimeout();

}