Java Reference
In-Depth Information
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Web container
: Manages the execution of web pages, servlets, and some EJB
components for Java EE applications. Web components and their container run on
the Java EE server.
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Application client container
: Manages the execution of application client com-
ponents. Application clients and their container run on the client.
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Applet container
: Manages the execution of applets. Consists of a web browser
and Java Plug-in running on the client together.
Web Services Support
Web services are web-based enterprise applications that use open, XML-based standards
and transport protocols to exchange data with calling clients. The Java EE platform
provides the XML APIs and tools you need to quickly design, develop, test, and deploy
web services and clients that fully interoperate with other web services and clients running
on Java-based or non-Java-based platforms.
To write web services and clients with the Java EE XML APIs, all you do is pass para-
meter data to the method calls and process the data returned; for document-oriented web
services, you send documents containing the service data back and forth. No low-level
programming is needed, because the XML API implementations do the work of translat-
ing the application data to and from an XML-based data stream that is sent over the stand-
ardized XML-based transport protocols. These XML-based standards and protocols are
introduced in the following sections.
The translation of data to a standardized XML-based data stream is what makes web ser-
vices and clients written with the Java EE XML APIs fully interoperable. This does not
necessarily mean that the data being transported includes XML tags, because the trans-
ported data can itself be plain text, XML data, or any kind of binary data, such as audio,
video, maps, program files, computer-aided design (CAD) documents, and the like. The
next section introduces XML and explains how parties doing business can use XML tags
and schemas to exchange data in a meaningful way.
XML
Extensible Markup Language (XML) is a cross-platform, extensible, text-based standard
for representing data. Parties that exchange XML data can create their own tags to de-
scribe the data, set up schemas to specify which tags can be used in a particular kind of
XML document, and use XML style sheets to manage the display and handling of the
data.
