docs/html/training/volley/index.jd

page.title=Transmitting Network Data Using Volley
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<!-- Required platform, tools, add-ons, devices, knowledge, etc. -->
<h2>Dependencies and prerequisites</h2>

<ul>
  <li>Android 2.2 (API Level 8) or higher</li>
</ul>

</div>
</div>

<a class="notice-developers-video wide" href="https://developers.google.com/events/io/sessions/325304728">
<div>
    <h3>Video</h3>
    <p>Volley: Easy, Fast Networking for Android</p>
</div>
</a>


<p>Volley is an HTTP library that makes networking for Android apps easier and most importantly,
faster. Volley is available through the open
<a href="https://android.googlesource.com/platform/frameworks/volley">AOSP</a> repository.</p>

<p>Volley offers the following benefits:</p>

<ul>

<li>Automatic scheduling of network requests.</li>
<li>Multiple concurrent network connections.</li>
<li>Transparent disk and memory response caching with standard HTTP
<a href=http://en.wikipedia.org/wiki/Cache_coherence">cache coherence</a>.</li>
<li>Support for request prioritization.</li>
<li>Cancellation request API. You can cancel a single request, or you can set blocks or
scopes of requests to cancel.</li>
<li>Ease of customization, for example, for retry and backoff.</li>
<li>Strong ordering that makes it easy to correctly populate your UI with data fetched
asynchronously from the network.</li>
<li>Debugging and tracing tools.</li>

</ul>

<p>Volley excels at RPC-type operations used to populate a UI, such as fetching a page of
search results as structured data. It integrates easily with any protocol and comes out of
the box with support for raw strings, images, and JSON. By providing built-in support for
the features you need, Volley frees you from writing boilerplate code and allows you to
concentrate on the logic that is specific to your app.</p>
<p>Volley is not suitable for large download or streaming operations, since Volley holds
all responses in memory during parsing. For large download operations, consider using an
alternative like {@link android.app.DownloadManager}.</p>

<p>The core Volley library is developed in the open
<a href="https://android.googlesource.com/platform/frameworks/volley">AOSP</a>
repository at {@code frameworks/volley} and contains the main request dispatch pipeline
as well as a set of commonly applicable utilities, available in the Volley "toolbox." The
easiest way to add Volley to your project is to clone the Volley repository and set it as
a library project:</p>

<ol>
<li>Git clone the repository by typing the following at the command line:

<pre>
git clone https://android.googlesource.com/platform/frameworks/volley
</pre>
</li>

<li>Import the downloaded source into your app project as an Android library project
(as described in <a href="{@docRoot}tools/projects/projects-eclipse.html">
Managing Projects from Eclipse with ADT</a>, if you're using Eclipse) or make a
<a href="{@docRoot}guide/faq/commontasks.html#addexternallibrary"><code>.jar</code> file</a>.</li>
</ol>

<h2>Lessons</h2>

<dl>
 <dt>
        <strong><a href="simple.html">Sending a Simple Request</a></strong>
    </dt>
    <dd>
        Learn how to send a simple request using the default behaviors of Volley, and how
        to cancel a request.

    </dd>
    <dt>
        <strong><a href="requestqueue.html">Setting Up a RequestQueue</a></strong>
    </dt>
    <dd>
        Learn how to set up a {@code RequestQueue}, and how to implement a singleton
        pattern to create a {@code RequestQueue} that lasts the lifetime of your app.
    </dd>
    <dt>
        <strong><a href="request.html">Making a Standard Request</a></strong>
    </dt>
    <dd>
        Learn how to send a request using one of Volley's out-of-the-box request types
        (raw strings, images, and JSON).
    </dd>
    <dt>
        <strong><a href="request-custom.html">Implementing a Custom Request</a></strong>
    </dt>
    <dd>
        Learn how to implement a custom request.
    </dd>

</dl>