org.apache.commons.httpclient.methods

Class ExpectContinueMethod

Implemented Interfaces:
HttpMethod
Known Direct Subclasses:
EntityEnclosingMethod, MultipartPostMethod

public abstract class ExpectContinueMethod
extends HttpMethodBase

This abstract class serves as a foundation for all HTTP methods that support 'Expect: 100-continue' handshake.

The purpose of the 100 (Continue) status (refer to section 10.1.1 of the RFC 2616 for more details) is to allow a client that is sending a request message with a request body to determine if the origin server is willing to accept the request (based on the request headers) before the client sends the request body. In some cases, it might either be inappropriate or highly inefficient for the client to send the body if the server will reject the message without looking at the body.

'Expect: 100-continue' handshake should be used with caution, as it may cause problems with HTTP servers and proxies that do not support HTTP/1.1 protocol.

Author:
Oleg Kalnichevski
Since:
2.0beta1

Constructor Summary

ExpectContinueMethod()
No-arg constructor.
ExpectContinueMethod(String uri)
Constructor specifying a URI.

Method Summary

protected void
addRequestHeaders(HttpState state, HttpConnection conn)
Sets the Expect header if it has not already been set, in addition to the "standard" set of headers.
boolean
getUseExpectHeader()
Deprecated. Use HttpMethodParams
protected abstract boolean
hasRequestContent()
Returns true if there is a request body to be sent.
void
setUseExpectHeader(boolean value)
Deprecated. Use HttpMethodParams

Methods inherited from class org.apache.commons.httpclient.HttpMethodBase

abort, addCookieRequestHeader, addHostRequestHeader, addProxyConnectionHeader, addRequestHeader, addRequestHeader, addRequestHeaders, addResponseFooter, addUserAgentRequestHeader, checkNotUsed, checkUsed, execute, generateRequestLine, getAuthenticationRealm, getContentCharSet, getDoAuthentication, getEffectiveVersion, getFollowRedirects, getHostAuthState, getHostConfiguration, getMethodRetryHandler, getName, getParams, getPath, getProxyAuthState, getProxyAuthenticationRealm, getQueryString, getRecoverableExceptionCount, getRequestCharSet, getRequestHeader, getRequestHeaderGroup, getRequestHeaders, getRequestHeaders, getResponseBody, getResponseBodyAsStream, getResponseBodyAsString, getResponseCharSet, getResponseContentLength, getResponseFooter, getResponseFooters, getResponseHeader, getResponseHeaderGroup, getResponseHeaders, getResponseHeaders, getResponseStream, getResponseTrailerHeaderGroup, getStatusCode, getStatusLine, getStatusText, getURI, hasBeenUsed, isAborted, isConnectionCloseForced, isHttp11, isRequestSent, isStrictMode, processResponseBody, processResponseHeaders, processStatusLine, readResponse, readResponseBody, readResponseHeaders, readStatusLine, recycle, releaseConnection, removeRequestHeader, removeRequestHeader, responseBodyConsumed, setConnectionCloseForced, setDoAuthentication, setFollowRedirects, setHostConfiguration, setHttp11, setMethodRetryHandler, setParams, setPath, setQueryString, setQueryString, setRequestHeader, setRequestHeader, setResponseStream, setStrictMode, setURI, shouldCloseConnection, validate, writeRequest, writeRequestBody, writeRequestHeaders, writeRequestLine

Constructor Details

ExpectContinueMethod

public ExpectContinueMethod()
No-arg constructor.
Since:
2.0

ExpectContinueMethod

public ExpectContinueMethod(String uri)
Constructor specifying a URI.
Parameters:
uri - either an absolute or relative URI
Since:
2.0

Method Details

addRequestHeaders

protected void addRequestHeaders(HttpState state,
                                 HttpConnection conn)
            throws IOException,
                   HttpException
Sets the Expect header if it has not already been set, in addition to the "standard" set of headers.
Overrides:
addRequestHeaders in interface HttpMethodBase
Parameters:
state - the state information associated with this method
conn - the connection used to execute this HTTP method
Throws:
HttpException - if a protocol exception occurs. Usually protocol exceptions cannot be recovered from.

getUseExpectHeader

public boolean getUseExpectHeader()

Deprecated. Use HttpMethodParams

Returns true if the 'Expect: 100-Continue' handshake is activated. The purpose of the 'Expect: 100-Continue' handshake to allow a client that is sending a request message with a request body to determine if the origin server is willing to accept the request (based on the request headers) before the client sends the request body.
Returns:
true if 'Expect: 100-Continue' handshake is to be used, false otherwise.
Since:
2.0beta1

hasRequestContent

protected abstract boolean hasRequestContent()
Returns true if there is a request body to be sent. 'Expect: 100-continue' handshake may not be used if request body is not present
Returns:
boolean
Since:
2.0beta1

setUseExpectHeader

public void setUseExpectHeader(boolean value)

Deprecated. Use HttpMethodParams

Activates 'Expect: 100-Continue' handshake. The purpose of the 'Expect: 100-Continue' handshake to allow a client that is sending a request message with a request body to determine if the origin server is willing to accept the request (based on the request headers) before the client sends the request body.

The use of the 'Expect: 100-continue' handshake can result in noticable peformance improvement for entity enclosing requests (such as POST and PUT) that require the target server's authentication.

'Expect: 100-continue' handshake should be used with caution, as it may cause problems with HTTP servers and proxies that do not support HTTP/1.1 protocol.

Parameters:
value - boolean value
Since:
2.0beta1

Copyright (c) 1999-2005 - Apache Software Foundation