6.1 Introduction to Oracle Enterprise Service Bus

Oracle Enterprise Service Bus moves data among multiple endpoints, both within and outside of an enterprise. It uses open standards to connect, transform, and route business documents (as Extensible Markup Language (XML) messages), among disparate applications. It enables monitoring and management of business data, with minimal impact on existing applications. An enterprise service bus is the underlying infrastructure for delivering a service-oriented architecture (SOA) and event-driven architecture (EDA).

Oracle Enterprise Service Bus is the foundation for services using SOA and EDA. At its core, it is a loosely coupled application framework that provides your business with increased flexibility, reusability, and overall responsiveness in a distributed, heterogeneous, message-oriented environment using industry standards.

Oracle Enterprise Service Bus features that provide the ability to integrate applications fall into three broad categories:

• Connectivity

  Connectivity is provided through adapter services and Simple Object Access Protocol (SOAP) invocation services. Oracle Enterprise Service Bus provides tools and wizards to assist you in invoking and creating services.

• Document Transformation

  Oracle Enterprise Service Bus includes a standards-based data mapper that specifies an xsl file to transform data from one XML schema to another, thus enabling data interchange among applications using different schemas. Multiple transformations may be required to achieve the desired result. These transformations can be reused, as needed, across Oracle Enterprise Service Bus.

• Routing

  Data contained within XML messages are distributed from the source application to a target application using routing services. As the name suggests, a routing service determines how a message gets from one point to another within the Oracle Enterprise Service Bus environment.

  Minimally, Routing rules specify the set of services (referred to as target services) that Oracle Enterprise Service Bus will invoke when the routing service receives a message. In addition, when you configure routing rules, you can specify the following options:

  • Whether a filter expression, which specifies that the contents (payload) of a message be analyzed before any service is invoked, be applied

  • Whether a document transformation is applied

  • Whether execution is synchronous or asynchronous

  • The priority level for each routing rule specified in relation to the others

  • The ESB systems, which are logical units of ESB services, from which messages are accepted.

Read this chapter to understand:

• How to create a message instance flow

• How to invoke external services

• How to create adapter services

• How to create routing services and configure routing rules

• How to test the Oracle Enterprise Service Bus flow

For an additional introduction to Oracle Enterprise Service Bus, see "Introduction to Oracle Enterprise Service Bus" in Oracle Enterprise Service Bus Developer's Guide