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package org.apache.http.nio.protocol;

import java.io.IOException;

import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.nio.entity.ConsumingNHttpEntity;
import org.apache.http.protocol.HttpContext;

HTTP request execution handler can be used by client-side protocol handlers to trigger the submission of a new HTTP request and the processing of an HTTP response. When a new response entity is available for consumption, responseEntity(HttpResponse, HttpContext) is called. After the ConsumingNHttpEntity consumes the response body, handleResponse(HttpResponse, HttpContext) is notified that the response is fully read. 
Since:
4.0
Deprecated:
(4.2) use HttpAsyncRequestExecutor and HttpAsyncRequester/**
 * HTTP request execution handler can be used by client-side protocol handlers
 * to trigger the submission of a new HTTP request and the processing of an HTTP
 * response. When a new response entity is available for consumption,
 * {@link #responseEntity(HttpResponse, HttpContext)} is called.
 * After the {@link ConsumingNHttpEntity} consumes the response body,
 * {@link #handleResponse(HttpResponse, HttpContext)} is notified that the
 * response is fully read.
 *
 * @since 4.0
 *
 * @deprecated (4.2) use {@link HttpAsyncRequestExecutor} and {@link HttpAsyncRequester}
 */
@Deprecated
public interface NHttpRequestExecutionHandler {

    
Triggered when a new connection has been established and the
HTTP context needs to be initialized.
The attachment object is the same object which was passed
to the connecting I/O reactor when the connection request was
made. The attachment may optionally contain some state information
required in order to correctly initalize the HTTP context.
Params:
context – the actual HTTP context
attachment – the object passed to the connecting I/O reactor
  upon the request for a new connection.
See Also:
connect.connect/**
     * Triggered when a new connection has been established and the
     * HTTP context needs to be initialized.
     *
     * <p>The attachment object is the same object which was passed
     * to the connecting I/O reactor when the connection request was
     * made. The attachment may optionally contain some state information
     * required in order to correctly initalize the HTTP context.
     *
     * @see org.apache.http.nio.reactor.ConnectingIOReactor#connect
     *
     * @param context the actual HTTP context
     * @param attachment the object passed to the connecting I/O reactor
     *   upon the request for a new connection.
     */
    void initalizeContext(HttpContext context, Object attachment);

    
Triggered when the underlying connection is ready to send a new HTTP request to the target host. This method may return null if the client is not yet ready to send a request. In this case the connection will remain open and can be activated at a later point. 

If the request has an entity, the entity must be an instance of ProducingNHttpEntity. 
Params:
context – the actual HTTP context
Returns:
an HTTP request to be sent or null if no request needs to be sent/**
     * Triggered when the underlying connection is ready to send a new
     * HTTP request to the target host. This method may return
     * {@code null} if the client is not yet ready to send a
     * request. In this case the connection will remain open and
     * can be activated at a later point.
     * <p>
     * If the request has an entity, the entity <b>must</b> be an
     * instance of {@link org.apache.http.nio.entity.ProducingNHttpEntity}.
     *
     * @param context the actual HTTP context
     * @return an HTTP request to be sent or {@code null} if no
     *   request needs to be sent
     */
    HttpRequest submitRequest(HttpContext context);

    
Triggered when a response is received with an entity. This method should return a ConsumingNHttpEntity that will be used to consume the entity. null is a valid response value, and will indicate that the entity should be silently ignored. 
 After the entity is fully consumed, handleResponse(HttpResponse, HttpContext) is called to notify a full response & entity are ready to be processed. 
Params:
response – 
           The response containing the existing entity.
context – 
           the actual HTTP context
Returns:
An entity that will asynchronously consume the response's content
        body./**
     * Triggered when a response is received with an entity. This method should
     * return a {@link ConsumingNHttpEntity} that will be used to consume the
     * entity. {@code null} is a valid response value, and will indicate
     * that the entity should be silently ignored.
     * <p>
     * After the entity is fully consumed,
     * {@link NHttpRequestExecutionHandler#handleResponse(HttpResponse, HttpContext)}
     * is called to notify a full response &amp; entity are ready to be processed.
     *
     * @param response
     *            The response containing the existing entity.
     * @param context
     *            the actual HTTP context
     * @return An entity that will asynchronously consume the response's content
     *         body.
     */
    ConsumingNHttpEntity responseEntity(HttpResponse response, HttpContext context)
        throws IOException;

    
Triggered when an HTTP response is ready to be processed.
Params:
response – 
           the HTTP response to be processed
context – 
           the actual HTTP context/**
     * Triggered when an HTTP response is ready to be processed.
     *
     * @param response
     *            the HTTP response to be processed
     * @param context
     *            the actual HTTP context
     */
    void handleResponse(HttpResponse response, HttpContext context)
        throws IOException;

    
Triggered when the connection is terminated. This event can be used
to release objects stored in the context or perform some other kind
of cleanup.
Params:
context – the actual HTTP context/**
     * Triggered when the connection is terminated. This event can be used
     * to release objects stored in the context or perform some other kind
     * of cleanup.
     *
     * @param context the actual HTTP context
     */
    void finalizeContext(HttpContext context);

}