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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html><head><title>HttpClient - Get Method</title><style type="text/css" media="all">
@import url("../style/maven-base.css");
@import url("../style/maven-theme.css");@import url("../style/project.css");</style><link rel="stylesheet" href="../style/print.css" type="text/css" media="print"></link><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"></meta><meta name="author" content="Adrian Sutton"></meta><meta name="email" content="adrian@ephox.com"></meta></head><body class="composite"><div id="banner"><a href="http://jakarta.apache.org/" id="organizationLogo"><img alt="Apache Software Foundation" src="http://jakarta.apache.org/images/jakarta-logo.gif"></img></a><a href="http://jakarta.apache.org/httpcomponents/httpclient-3.x/" id="projectLogo"><img alt="HttpClient" src="../images/httpclient_logo.png"></img></a><div class="clear"><hr></hr></div></div><div id="breadcrumbs"><div class="xleft">Last published: 18 August 2007
<span class="separator">|</span>Doc for 3.1
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<p>The GET method retrieves whatever information (in the form of an
entity) is identified by the Request-URI. If the Request-URI refers to a
data-producing process, it is the produced data which shall be returned
as the entity in the response and not the source text of the process,
unless that text happens to be the output of the process.</p>
<p>The semantics of the GET method change to a "conditional GET" if the
request message includes an If-ModifiedSince, If-Unmodified-Since,
If-Match, If-None-Match, or If-Range header field. A conditional GET
method requests that the entity be transferred only under the
circumstances described by the conditional header field(s). This reduces
unnecessary network usage by allowing cached entities to be refreshed
without requiring multiple requests or transferring data already held by
the client.</p>
<p>If a Range header field is included, the request is for only the part
of the entity specified by the range header. This allows partially
retrieved entities to be completed without transferring previously
received data.</p>
</div><div class="section"><a name="Typical_Usage"></a><h2>Typical Usage</h2>
<p>Typically the get method is used to download a document from a web
server. This can be achieved with the method, getResponseBody,
getResponseBodyAsStream or getResponseBodyAsString. Of these methods,
getResponseBodyAsStream is generally the best choice as it avoids
unnessecary buffering of all data into memory before processing.</p>
<p>See the <a href="../tutorial.html">tutorial</a> for a full example
of using the GET method. There are also a number of examples in the <a href="http://svn.apache.org/viewvc/jakarta/httpcomponents/oac.hc3x/trunk/src/examples/" class="externalLink" title="External Link">sample
code</a>.</p>
<div class="source"><pre>
GetMethod get = new GetMethod("http://jakarta.apache.org");
// execute method and handle any error responses.
...
InputStream in = get.getResponseBodyAsStream();
// Process the data from the input stream.
get.releaseConnection();
</pre></div>
</div><div class="section"><a name="Common_Problems"></a><h2>Common Problems</h2>
<p>The most common mistake when using the GET method is failing to read
the entire response body even if an error code, redirect or any other
response status is received. As with all methods, one must also be sure to call
method.releaseConnection(), regardless of the response code received.</p>
</div><div class="section"><a name="RFC_Section"></a><h2>RFC Section</h2>
<p>The get method is defined in section 8.1 of <a href="http://www.ietf.org/rfc/rfc1945.txt" class="externalLink" title="External Link">RFC1945</a> and similarly
defined for HTTP 1.1 in section 9.3 of <a href="http://www.ietf.org/rfc/rfc2616.txt" class="externalLink" title="External Link">RFC2616</a>.</p>
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