Building Oracle XML Applications

Working with XML Messages

In this section, we’ll investigate examples of using XML as a structured data exchange mechanism between applications. First we’ll look at synchronous approaches like posting and getting XML messages over HTTP; then we’ll learn the basics of Oracle’s Advanced Queuing (AQ) mechanism to support asynchronous XML message passing between applications using reliable queues.

Sending and Receiving XML Between Servers

Since XML can represent structured data in an open, standard way, it is quickly becoming the preferred method of data exchange over the Web. In a year or two, it will be the dominant method. Sites that serve up information in HTML—useful primarily to human eyeballs—will add the ability to retrieve the information in an XML-based format that will allow other servers to use that data more easily. Businesses whose current web-based applications only allow human interaction through web-based HTML forms are scrambling to add the ability to accept posted requests in XML formats to enable Business-to-Business automation.

In this way, the Web will rapidly evolve to offer a business application developer a sea of XML-based information services, where your application can check on the status of an order, cancel a reservation, or book a flight simply by sending and receiving appropriate XML datagrams. It goes without saying that the ability to write programs that post and receive XML is a core competence for any developer building the next generation of web ...