CodeFutures News & Industry Commentary Blog

In the space of two days, Java Developers Journal has published two articles (here and here ) on Service Component Architecture and Service Data Objects.

The first article, called Real SOA, has a good description of Service Data Objects:

It is important not to forget the complexity introduced by handling data in such a heterogeneous network of services. A technology called Service Data Objects (SDO) addresses this problem. SDO offers a format-neutral API that provides a uniform way to access data, regardless of how it is physically stored. By using SDO, the solution developer will not pollute a business application with code to handle diverse choices of data access, such as JDBC Result Sets, JCA records, DOM, JAXB, and EJB entities.

SDO supports a disconnected style of data access and can record a summary based on any changes made to data objects. SDO's ability to maintain a summary of the changes made allows data transfers to include only the portion of data that has changed, therefore improving environments where bandwidth is a constraint. The change summary information can be used to resolve data access conflicts and concurrency issues.

SDO supplies a powerful yet simple programming model for data with first class support for XML and the ability to automatically persist data via the use of a Data Access Service (DAS). A DAS allows the data to be stored or retrieved from a relational database or another repository, and helps to link the SDO models to enterprise data storage.

The second article, called What is SCA?, has a good one line explanation of Service Component Architecture:

Service Component Architecture provides a concise and flexible model for describing and developing SOA applications and addresses the strategic requirements demanded by agile IT environments. The SCA programming model focuses on describing components and the way that they're assembled together. It's inclusive of existing technologies with a primary goal of operating well as an addition to existing heterogeneous environments.

It's interesting that the initial 'how to' and 'what is' articles are now starting to appear more regularly in technical journals. This is probably because the specifications are moving from planning phase to the real world implementation phase.

PJ Murray
CodeFutures Software