org.apache.http.impl

Class AbstractHttpClientConnection

java.lang.Object

org.apache.http.impl.AbstractHttpClientConnection

All Implemented Interfaces:

Closeable, AutoCloseable, HttpClientConnection, HttpConnection

Direct Known Subclasses:

SocketHttpClientConnection

@NotThreadSafe
public abstract class AbstractHttpClientConnection
extends Object
implements HttpClientConnection

Abstract client-side HTTP connection capable of transmitting and receiving data using arbitrary SessionInputBuffer and SessionOutputBuffer implementations.

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

• CoreProtocolPNames.STRICT_TRANSFER_ENCODING
• CoreConnectionPNames.MAX_HEADER_COUNT
• CoreConnectionPNames.MAX_LINE_LENGTH

Since:

4.0

Constructor Summary

Constructors

Constructor and Description
AbstractHttpClientConnection() Creates an instance of this class.

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract void	assertOpen() Asserts if the connection is open.
protected HttpConnectionMetricsImpl	createConnectionMetrics(HttpTransportMetrics inTransportMetric, HttpTransportMetrics outTransportMetric)
protected EntityDeserializer	createEntityDeserializer() Creates an instance of EntityDeserializer with the LaxContentLengthStrategy implementation to be used for de-serializing entities received over this connection.
protected EntitySerializer	createEntitySerializer() Creates an instance of EntitySerializer with the StrictContentLengthStrategy implementation to be used for serializing HTTP entities sent over this connection.
protected HttpResponseFactory	createHttpResponseFactory() Creates an instance of DefaultHttpResponseFactory to be used for creating HttpResponse objects received by over this connection.
protected HttpMessageWriter<HttpRequest>	createRequestWriter(SessionOutputBuffer buffer, HttpParams params) Creates an instance of HttpMessageWriter to be used for writing out HTTP requests sent over this connection.
protected HttpMessageParser<HttpResponse>	createResponseParser(SessionInputBuffer buffer, HttpResponseFactory responseFactory, HttpParams params) Creates an instance of HttpMessageParser to be used for parsing HTTP responses received over this connection.
protected void	doFlush()
void	flush() Writes out all pending buffered data over the open connection.
HttpConnectionMetrics	getMetrics() Returns a collection of connection metrics.
protected void	init(SessionInputBuffer inbuffer, SessionOutputBuffer outbuffer, HttpParams params) Initializes this connection object with SessionInputBuffer and SessionOutputBuffer instances to be used for sending and receiving data.
protected boolean	isEof()
boolean	isResponseAvailable(int timeout) Checks if response data is available from the connection.
boolean	isStale() Checks whether this connection has gone down.
void	receiveResponseEntity(HttpResponse response) Receives the next response entity available from this connection and attaches it to an existing HttpResponse object.
HttpResponse	receiveResponseHeader() Receives the request line and headers of the next response available from this connection.
void	sendRequestEntity(HttpEntityEnclosingRequest request) Sends the request entity over the connection.
void	sendRequestHeader(HttpRequest request) Sends the request line and all headers over the connection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.http.HttpConnection

close, getSocketTimeout, isOpen, setSocketTimeout, shutdown

Constructor Detail

AbstractHttpClientConnection

public AbstractHttpClientConnection()

Creates an instance of this class.

This constructor will invoke createEntityDeserializer() and createEntitySerializer() methods in order to initialize HTTP entity serializer and deserializer implementations for this connection.

Method Detail

assertOpen

protected abstract void assertOpen()
                            throws IllegalStateException

Asserts if the connection is open.

Throws:

IllegalStateException - if the connection is not open.

createEntityDeserializer

protected EntityDeserializer createEntityDeserializer()

Creates an instance of EntityDeserializer with the LaxContentLengthStrategy implementation to be used for de-serializing entities received over this connection.

This method can be overridden in a super class in order to create instances of EntityDeserializer using a custom ContentLengthStrategy.

Returns:

HTTP entity deserializer

createEntitySerializer

protected EntitySerializer createEntitySerializer()

Creates an instance of EntitySerializer with the StrictContentLengthStrategy implementation to be used for serializing HTTP entities sent over this connection.

This method can be overridden in a super class in order to create instances of EntitySerializer using a custom ContentLengthStrategy.

Returns:

HTTP entity serialzier.

createHttpResponseFactory

protected HttpResponseFactory createHttpResponseFactory()

Creates an instance of DefaultHttpResponseFactory to be used for creating HttpResponse objects received by over this connection.

This method can be overridden in a super class in order to provide a different implementation of the HttpResponseFactory interface.

Returns:

HTTP response factory.

createResponseParser

protected HttpMessageParser<HttpResponse> createResponseParser(SessionInputBuffer buffer,
                                                   HttpResponseFactory responseFactory,
                                                   HttpParams params)

Creates an instance of HttpMessageParser to be used for parsing HTTP responses received over this connection.

This method can be overridden in a super class in order to provide a different implementation of the HttpMessageParser interface or to pass a different implementation of the LineParser to the the DefaultHttpResponseParser constructor.

Parameters:

buffer - the session input buffer.

responseFactory - the HTTP response factory.

params - HTTP parameters.

Returns:

HTTP message parser.

createRequestWriter

protected HttpMessageWriter<HttpRequest> createRequestWriter(SessionOutputBuffer buffer,
                                                 HttpParams params)

Creates an instance of HttpMessageWriter to be used for writing out HTTP requests sent over this connection.

This method can be overridden in a super class in order to provide a different implementation of the HttpMessageWriter interface or to pass a different implementation of LineFormatter to the the default implementation HttpRequestWriter.

Parameters:

buffer - the session output buffer

params - HTTP parameters

Returns:

HTTP message writer

createConnectionMetrics

protected HttpConnectionMetricsImpl createConnectionMetrics(HttpTransportMetrics inTransportMetric,
                                                HttpTransportMetrics outTransportMetric)

Since:

4.1

init

protected void init(SessionInputBuffer inbuffer,
        SessionOutputBuffer outbuffer,
        HttpParams params)

Initializes this connection object with SessionInputBuffer and SessionOutputBuffer instances to be used for sending and receiving data. These session buffers can be bound to any arbitrary physical output medium.

This method will invoke createHttpResponseFactory(), createRequestWriter(SessionOutputBuffer, HttpParams) and createResponseParser(SessionInputBuffer, HttpResponseFactory, HttpParams) methods to initialize HTTP request writer and response parser for this connection.

Parameters:

inbuffer - the session input buffer.

outbuffer - the session output buffer.

params - HTTP parameters.

isResponseAvailable

public boolean isResponseAvailable(int timeout)
                            throws IOException

Description copied from interface: HttpClientConnection

Checks if response data is available from the connection. May wait for the specified time until some data becomes available. Note that some implementations may completely ignore the timeout parameter.

Specified by:

isResponseAvailable in interface HttpClientConnection

Parameters:

timeout - the maximum time in milliseconds to wait for data

Returns:

true if data is available; false if there was no data available even after waiting for timeout milliseconds.

Throws:

IOException - if an error happens on the connection

sendRequestHeader

public void sendRequestHeader(HttpRequest request)
                       throws HttpException,
                              IOException

Description copied from interface: HttpClientConnection

Sends the request line and all headers over the connection.

Specified by:

sendRequestHeader in interface HttpClientConnection

Parameters:

request - the request whose headers to send.

Throws:

HttpException - in case of HTTP protocol violation

IOException - in case of an I/O error

sendRequestEntity

public void sendRequestEntity(HttpEntityEnclosingRequest request)
                       throws HttpException,
                              IOException

Description copied from interface: HttpClientConnection

Sends the request entity over the connection.

Specified by:

sendRequestEntity in interface HttpClientConnection

Parameters:

request - the request whose entity to send.

Throws:

HttpException - in case of HTTP protocol violation

IOException - in case of an I/O error

doFlush

protected void doFlush()
                throws IOException

Throws:

IOException

flush

public void flush()
           throws IOException

Description copied from interface: HttpClientConnection

Writes out all pending buffered data over the open connection.

Specified by:

flush in interface HttpClientConnection

Throws:

IOException - in case of an I/O error

receiveResponseHeader

public HttpResponse receiveResponseHeader()
                                   throws HttpException,
                                          IOException

Description copied from interface: HttpClientConnection

Receives the request line and headers of the next response available from this connection. The caller should examine the HttpResponse object to find out if it should try to receive a response entity as well.

Specified by:

receiveResponseHeader in interface HttpClientConnection

Returns:

a new HttpResponse object with status line and headers initialized.

Throws:

HttpException - in case of HTTP protocol violation

IOException - in case of an I/O error

receiveResponseEntity

public void receiveResponseEntity(HttpResponse response)
                           throws HttpException,
                                  IOException

Description copied from interface: HttpClientConnection

Receives the next response entity available from this connection and attaches it to an existing HttpResponse object.

Specified by:

receiveResponseEntity in interface HttpClientConnection

Parameters:

response - the response to attach the entity to

Throws:

HttpException - in case of HTTP protocol violation

IOException - in case of an I/O error

isEof

protected boolean isEof()

isStale

public boolean isStale()

Description copied from interface: HttpConnection

Checks whether this connection has gone down. Network connections may get closed during some time of inactivity for several reasons. The next time a read is attempted on such a connection it will throw an IOException. This method tries to alleviate this inconvenience by trying to find out if a connection is still usable. Implementations may do that by attempting a read with a very small timeout. Thus this method may block for a small amount of time before returning a result. It is therefore an expensive operation.

Specified by:

isStale in interface HttpConnection

Returns:

true if attempts to use this connection are likely to succeed, or false if they are likely to fail and this connection should be closed

getMetrics

public HttpConnectionMetrics getMetrics()

Description copied from interface: HttpConnection

Returns a collection of connection metrics.

Specified by:

getMetrics in interface HttpConnection

Returns:

HttpConnectionMetrics