org.apache.http.nio.protocol

Class HttpAsyncRequestExecutor

java.lang.Object

org.apache.http.nio.protocol.HttpAsyncRequestExecutor

All Implemented Interfaces:

NHttpClientEventHandler

@Immutable
public class HttpAsyncRequestExecutor
extends Object
implements NHttpClientEventHandler

HttpAsyncRequestExecutor is a fully asynchronous HTTP client side protocol handler based on the NIO (non-blocking) I/O model. HttpAsyncRequestExecutor translates individual events fired through the NHttpClientEventHandler interface into logically related HTTP message exchanges.

HttpAsyncRequestExecutor relies on HttpProcessor to generate mandatory protocol headers for all outgoing messages and apply common, cross-cutting message transformations to all incoming and outgoing messages, whereas individual HttpAsyncRequestExecutionHandlers are expected to implement application specific content generation and processing. The caller is expected to pass an instance of HttpAsyncRequestExecutionHandler to be used for the next series of HTTP message exchanges through the connection context using HTTP_HANDLER attribute. HTTP exchange sequence is considered complete when the HttpAsyncResponseConsumer.isDone() method returns true. The HttpAsyncRequester utility class can be used to facilitate initiation of asynchronous HTTP request execution.

The following parameters can be used to customize the behavior of this class:

• CoreProtocolPNames.WAIT_FOR_CONTINUE
• CoreConnectionPNames.SO_TIMEOUT

Since:

4.2

See Also:

HttpAsyncRequestExecutionHandler

Field Summary

Fields

Modifier and Type	Field and Description
static String	HTTP_HANDLER

Constructor Summary

Constructors

Constructor and Description
HttpAsyncRequestExecutor()

Method Summary

Methods

Modifier and Type	Method and Description
void	closed(NHttpClientConnection conn) Triggered when the connection is closed.
void	connected(NHttpClientConnection conn, Object attachment) Triggered when a new outgoing connection is created.
void	endOfInput(NHttpClientConnection conn) Triggered when the connection is closed by the opposite end point (half-closed).
void	exception(NHttpClientConnection conn, Exception cause) Triggered if an error occurs during the HTTP exchange.
void	inputReady(NHttpClientConnection conn, ContentDecoder decoder) Triggered when the underlying channel is ready for reading a new portion of the response entity through the corresponding content decoder.
protected void	log(Exception ex) This method can be used to log I/O exception thrown while closing Closeable objects (such as HttpConnection}).
void	outputReady(NHttpClientConnection conn, ContentEncoder encoder) Triggered when the underlying channel is ready for writing a next portion of the request entity through the corresponding content encoder.
void	requestReady(NHttpClientConnection conn) Triggered when the connection is ready to accept a new HTTP request.
void	responseReceived(NHttpClientConnection conn) Triggered when an HTTP response is received.
void	timeout(NHttpClientConnection conn) Triggered when no input is detected on this connection over the maximum period of inactivity.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HTTP_HANDLER

public static final String HTTP_HANDLER

See Also:

Constant Field Values

Constructor Detail

HttpAsyncRequestExecutor

public HttpAsyncRequestExecutor()

Method Detail

connected

public void connected(NHttpClientConnection conn,
             Object attachment)
               throws IOException,
                      HttpException

Description copied from interface: NHttpClientEventHandler

Triggered when a new outgoing connection is created.

Specified by:

connected in interface NHttpClientEventHandler

Parameters:

conn - new outgoing HTTP connection.

attachment - an object that was attached to the session request

Throws:

IOException

HttpException

closed

public void closed(NHttpClientConnection conn)

Description copied from interface: NHttpClientEventHandler

Triggered when the connection is closed.

Specified by:

closed in interface NHttpClientEventHandler

Parameters:

conn - closed HTTP connection.

exception

public void exception(NHttpClientConnection conn,
             Exception cause)

Description copied from interface: NHttpClientEventHandler

Triggered if an error occurs during the HTTP exchange.

Specified by:

exception in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that caused an I/O error

cause - exception

requestReady

public void requestReady(NHttpClientConnection conn)
                  throws IOException,
                         HttpException

Description copied from interface: NHttpClientEventHandler

Triggered when the connection is ready to accept a new HTTP request. The protocol handler does not have to submit a request if it is not ready.

Specified by:

requestReady in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that is ready to accept a new HTTP request.

Throws:

IOException

HttpException

See Also:

NHttpClientConnection

outputReady

public void outputReady(NHttpClientConnection conn,
               ContentEncoder encoder)
                 throws IOException

Description copied from interface: NHttpClientEventHandler

Triggered when the underlying channel is ready for writing a next portion of the request entity through the corresponding content encoder.

If the content producer is unable to generate outgoing content, output event notifications can be temporarily suspended using IOControl interface (super interface of NHttpClientConnection).

Please note that the NHttpClientConnection and ContentEncoder objects are not thread-safe and should only be used within the context of this method call. The IOControl object can be shared and used on other thread to resume output event notifications when more content is made available.

Specified by:

outputReady in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that can accommodate a new portion of the outgoing request content.

encoder - The content encoder to use to write content.

Throws:

IOException

See Also:

NHttpClientConnection, ContentEncoder, IOControl

responseReceived

public void responseReceived(NHttpClientConnection conn)
                      throws HttpException,
                             IOException

Description copied from interface: NHttpClientEventHandler

Triggered when an HTTP response is received. The connection passed as a parameter to this method is guaranteed to return a valid HTTP response object.

If the response received encloses a response entity this method will be followed by a series of NHttpClientEventHandler.inputReady(NHttpClientConnection, ContentDecoder) calls to transfer the response content.

Specified by:

responseReceived in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that contains an HTTP response

Throws:

HttpException

IOException

See Also:

NHttpClientConnection

inputReady

public void inputReady(NHttpClientConnection conn,
              ContentDecoder decoder)
                throws IOException

Description copied from interface: NHttpClientEventHandler

Triggered when the underlying channel is ready for reading a new portion of the response entity through the corresponding content decoder.

If the content consumer is unable to process incoming content, input event notifications can be temporarily suspended using IOControl interface (super interface of NHttpClientConnection).

Please note that the NHttpClientConnection and ContentDecoder objects are not thread-safe and should only be used within the context of this method call. The IOControl object can be shared and used on other thread to resume input event notifications when the handler is capable of processing more content.

Specified by:

inputReady in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that can produce a new portion of the incoming response content.

decoder - The content decoder to use to read content.

Throws:

IOException

See Also:

NHttpClientConnection, ContentDecoder, IOControl

endOfInput

public void endOfInput(NHttpClientConnection conn)
                throws IOException

Description copied from interface: NHttpClientEventHandler

Triggered when the connection is closed by the opposite end point (half-closed).

Specified by:

endOfInput in interface NHttpClientEventHandler

Parameters:

conn - half-closed HTTP connection.

Throws:

IOException

timeout

public void timeout(NHttpClientConnection conn)
             throws IOException

Description copied from interface: NHttpClientEventHandler

Triggered when no input is detected on this connection over the maximum period of inactivity.

Specified by:

timeout in interface NHttpClientEventHandler

Parameters:

conn - HTTP connection that caused timeout condition.

Throws:

IOException

log

protected void log(Exception ex)

This method can be used to log I/O exception thrown while closing Closeable objects (such as HttpConnection}).

Parameters:

ex - I/O exception thrown by Closeable.close()