Java Reference
In-Depth Information
Atom is an XML-based document format that describes lists of related information known as
“feeds.” Feeds are composed of a number of items, known as “entries,” each with an extensible
set of attached metadata.
Think of Atom as the next evolution of RSS. It is generally used to publish blog feeds on the
Internet, but a few data structures within the format are particularly useful for web services,
particularly Atom links.
Atom Links
The Atom link XML type is a very simple yet standardized way of embedding links within
your XML documents. Let's look at an example:
<customers>
<customers>
<link rel=
"next"
href="http://example.com/customers?start=2
&
size=2"
type="application/xml"/>
<customer
<customer id=
"123"
>
<name>
<name>
Bill Burke
</name>
</name>
</customer>
</customer>
<customer
<customer id=
"332"
>
<name>
<name>
Roy Fielding
</name>
</name>
</customer>
</customers>
</customer>
</customers>
The Atom link is just a simple XML element with a few specific attributes.
The
rel
rel
attribute
The
rel
attribute is used for link relationships. It is the logical, simple name used to ref-
erence the link. This attribute gives meaning to the URL you are linking to, much in the
same way that text enclosed in an HTML
<a>
element gives meaning to the URL you can
click in your browser.
The
href
href
attribute
This is the URL you can traverse in order to get new information or change the state of
your application.
The
type
type
attribute
This is the exchanged media type of the resource the URL points to.
The
hreflang
hreflang
attribute
Although not shown in the example, this attribute represents the language the data format
is translated into. Some examples are French, English, German, and Spanish.
