Implementing Web Services

Web services enable applications to interact with one another over the Web in a platform-neutral, language independent environment. In a typical Web services scenario, a business application sends a request to a service at a given URL by using the protocol over HTTP. The service receives the request, processes it, and returns a response. You can incorporate calls with external Web services in applications developed in Application Builder.

Web services are typically based on Simple Object Access Protocol (SOAP) or Representational State Transfer (REST) architectures. SOAP is a World Wide Web Consortium (W3C) standard protocol for sending and receiving requests and responses across the Internet. SOAP messages can be sent back and forth between a service provider and a service user in SOAP envelopes. RESTful Web services are resource oriented. The scope of the Web service is found in the URI and the method of the service is described by the HTTP method that is used such as GET, POST, PUT, HEAD, and DELETE.

SOAP offers two primary advantages:

SOAP is based on XML, and therefore easy to use.
SOAP messages are not blocked by firewalls because this protocol uses simple transport protocols, such as HTTP.

Tip:

If you are running Oracle Application Express with Oracle Database 11g Release 1 (11.1), you must enable network services in order to use Web services. See "Enabling Network Services in Oracle Database 11g"

REST offers similar advantages:

REST messages are also not blocked by firewalls because this protocol uses the HTTP protocol.
REST requests do not require the overhead of XML and SOAP envelopes and inputs are typically provided in the URI.

Topics:

Note:

The SOAP 1.1 specification is a W3C note. SOAP Version 1.2 specification is a W3C recommendation.

For information about Simple Object Access Protocol (SOAP) see:

http://www.w3.org/TR/SOAP/