org.apache.http.nio.protocol
Class ThrottlingHttpClientHandler

java.lang.Object
  extended by org.apache.http.nio.protocol.NHttpHandlerBase
      extended by org.apache.http.nio.protocol.ThrottlingHttpClientHandler
All Implemented Interfaces:
NHttpClientHandler

public class ThrottlingHttpClientHandler
extends NHttpHandlerBase
implements NHttpClientHandler

HTTP client handler implementation that allocates content buffers of limited size upon initialization and is capable of controlling the frequency of I/O events in order to guarantee those content buffers do not ever get overflown. This helps ensure near constant memory footprint of HTTP connections and to avoid the 'out of memory' condition while streaming out response content.

The client handler will delegate the tasks of sending entity enclosing HTTP requests and processing of HTTP responses to an Executor, which is expected to perform those tasks using dedicated worker threads in order to avoid blocking the I/O thread.

Author:
Oleg Kalnichevski
See Also:
NIOReactorPNames.CONTENT_BUFFER_SIZE

Field Summary
protected  HttpRequestExecutionHandler execHandler
           
protected  java.util.concurrent.Executor executor
           
 
Fields inherited from class org.apache.http.nio.protocol.NHttpHandlerBase
allocator, CONN_STATE, connStrategy, eventListener, httpProcessor, params
 
Constructor Summary
ThrottlingHttpClientHandler(org.apache.http.protocol.HttpProcessor httpProcessor, HttpRequestExecutionHandler execHandler, org.apache.http.ConnectionReuseStrategy connStrategy, ByteBufferAllocator allocator, java.util.concurrent.Executor executor, org.apache.http.params.HttpParams params)
           
ThrottlingHttpClientHandler(org.apache.http.protocol.HttpProcessor httpProcessor, HttpRequestExecutionHandler execHandler, org.apache.http.ConnectionReuseStrategy connStrategy, java.util.concurrent.Executor executor, org.apache.http.params.HttpParams params)
           
 
Method Summary
 void closed(NHttpClientConnection conn)
          Triggered when the connection is closed.
 void connected(NHttpClientConnection conn, java.lang.Object attachment)
          Triggered when a new outgoing connection is created.
 void exception(NHttpClientConnection conn, org.apache.http.HttpException ex)
          Triggered when an HTTP protocol violation occurs while receiving an HTTP response.
 void exception(NHttpClientConnection conn, java.io.IOException ex)
          Triggered when an I/O error occurrs while reading from or writing to the underlying channel.
 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.
 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 send an 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 org.apache.http.nio.protocol.NHttpHandlerBase
canResponseHaveBody, closeConnection, getParams, handleTimeout, setEventListener, shutdownConnection
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

execHandler

protected HttpRequestExecutionHandler execHandler

executor

protected final java.util.concurrent.Executor executor
Constructor Detail

ThrottlingHttpClientHandler

public ThrottlingHttpClientHandler(org.apache.http.protocol.HttpProcessor httpProcessor,
                                   HttpRequestExecutionHandler execHandler,
                                   org.apache.http.ConnectionReuseStrategy connStrategy,
                                   ByteBufferAllocator allocator,
                                   java.util.concurrent.Executor executor,
                                   org.apache.http.params.HttpParams params)

ThrottlingHttpClientHandler

public ThrottlingHttpClientHandler(org.apache.http.protocol.HttpProcessor httpProcessor,
                                   HttpRequestExecutionHandler execHandler,
                                   org.apache.http.ConnectionReuseStrategy connStrategy,
                                   java.util.concurrent.Executor executor,
                                   org.apache.http.params.HttpParams params)
Method Detail

connected

public void connected(NHttpClientConnection conn,
                      java.lang.Object attachment)
Description copied from interface: NHttpClientHandler
Triggered when a new outgoing connection is created.

Specified by:
connected in interface NHttpClientHandler
Parameters:
conn - closed HTTP connection.
attachment - an arbitrary object that was attached to the session request

closed

public void closed(NHttpClientConnection conn)
Description copied from interface: NHttpClientHandler
Triggered when the connection is closed.

Specified by:
closed in interface NHttpClientHandler
Parameters:
conn - closed HTTP connection.

exception

public void exception(NHttpClientConnection conn,
                      org.apache.http.HttpException ex)
Description copied from interface: NHttpClientHandler
Triggered when an HTTP protocol violation occurs while receiving an HTTP response.

Specified by:
exception in interface NHttpClientHandler
Parameters:
conn - HTTP connection that caused an HTTP protocol violation
ex - HTTP protocol violation exception

exception

public void exception(NHttpClientConnection conn,
                      java.io.IOException ex)
Description copied from interface: NHttpClientHandler
Triggered when an I/O error occurrs while reading from or writing to the underlying channel.

Specified by:
exception in interface NHttpClientHandler
Parameters:
conn - HTTP connection that caused an I/O error
ex - I/O exception

requestReady

public void requestReady(NHttpClientConnection conn)
Description copied from interface: NHttpClientHandler
Triggered when the connection is ready to send an HTTP request.

Specified by:
requestReady in interface NHttpClientHandler
Parameters:
conn - HTTP connection that is ready to send an HTTP request
See Also:
NHttpClientConnection

outputReady

public void outputReady(NHttpClientConnection conn,
                        ContentEncoder encoder)
Description copied from interface: NHttpClientHandler
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 the outgoing content, output event notifications can be temorarily suspended using IOControl.suspendOutput().

Specified by:
outputReady in interface NHttpClientHandler
Parameters:
conn - HTTP connection that can accommodate a new portion of the outgoing request content.
encoder - The content encoder to use to write content.
See Also:
NHttpConnection, ContentEncoder

responseReceived

public void responseReceived(NHttpClientConnection conn)
Description copied from interface: NHttpClientHandler
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 a series of NHttpClientHandler.inputReady(NHttpClientConnection, ContentDecoder) calls to transfer the response content.

Specified by:
responseReceived in interface NHttpClientHandler
Parameters:
conn - HTTP connection that contains an HTTP response
See Also:
NHttpClientConnection

inputReady

public void inputReady(NHttpClientConnection conn,
                       ContentDecoder decoder)
Description copied from interface: NHttpClientHandler
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 the incoming content, input event notifications can be temorarily suspended using IOControl.suspendInput().

Specified by:
inputReady in interface NHttpClientHandler
Parameters:
conn - HTTP connection that can produce a new portion of the incoming response content.
decoder - The content decoder to use to read content.
See Also:
NHttpConnection, ContentDecoder

timeout

public void timeout(NHttpClientConnection conn)
Description copied from interface: NHttpClientHandler
Triggered when no input is detected on this connection over the maximum period of inactivity.

Specified by:
timeout in interface NHttpClientHandler
Parameters:
conn - HTTP connection that caused timeout condition.


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