Package org.apache.commons.httpclient

package org.apache.commons.httpclient

Classes and interfaces supporting the client side of the HTTP protocol.

The HttpClient component supports the client-side of RFC 1945 (HTTP/1.0) and RFC 2616 (HTTP/1.1), several related specifications (RFC 2109 (Cookies), RFC 2617 (HTTP Authentication), etc.), and provides a framework by which new request types (methods) or HTTP extensions can can be easily created or supported.

The basis for the abstraction is provided by three types:

    HttpConnection
    represents a network connection to some HTTP host.
    HttpMethod
    represents a request to be made over some HttpConnection and contains the server's response.
    HttpState
    contains the HTTP attributes that may persist from request to request, such as cookies and authentication credentials.

and several simple bean-style classes:

HttpClient provides a simple "user-agent" implementation that will suffice for many applications, but whose use is not required.

HttpClient also provides several utilities that may be useful when extending the framework:

    HttpMethodBase
    an abstract base implementation of HttpMethod, which may be extended to create new method types or to support additional protocol HTTP features.
    HttpStatus
    an enumeration of HttpStatus codes.
    ChunkedOutputStream
    an OutputStream wrapper supporting the "chunked" transfer encoding.
    ChunkedInputStream
    an InputStream wrapper supporting the "chunked" transfer encoding.
    URIUtil
    provides utilities for encoding and decoding URI's in the %HH format.

HttpClient Configuration with Java Properties

Java properties can be set at run time with the -Dname=value command line arguments to the application that uses HttpClient. These properties can also be set programaticly by calling System.getProperties().setProperty(name, value). This is the list of properties that HttpClient recognizes:
Name Type Effect
httpclient.useragent String Sets the User-Agent string to be sent on every HTTP request.
httpclient.authentication.preemptive boolean Sends authorization credentials without requiring explicit requests from the web server