You can use data access applications to manipulate data from outside sources for use within your application serving environment.
The Enterprise JavaBeans (EJB) programming model provides several distinct server-side component types: entity, session, and message-driven beans, and servlets. Of these types, entity beans are typically used to model business components in an application. Entity beans have both state and behavior.
The state of entity beans is persistent and is stored in a database. As changes are made to an entity bean, its state is kept in synchronization with the database record representing the bean. There are two types of entity beans provided by the EJB model and these two types differ in the mechanism used to provide persistence. These two types of entity beans are container-managed persistence (CMP) beans and bean-managed persistence (BMP) beans.
Typical examples of CMP beans are Customer, Account, and so on. Because CMP beans are objects, their data (state) is accessed using field accessors. For example, a Customer entity bean is likely to have fields such as name and phoneNumber. These pieces of data are accessed using the accessor methods getName()/setName() and getPhoneNumber()/setPhoneNumber(). As a developer, you are not concerned with how this data is eventually stored and retrieved from the backend database and can assume that the integrity of the data is maintained by the container.
An alternative to developing entity beans is using the Service Data Objects (SDO) framework, which is a unified framework for data application development. With SDO, you do not need to be familiar with a technology-specific API in order to access and utilize data. You need to know only one API, the SDO API, which lets you work with data from multiple sources, including relational databases, entity EJB components, XML pages, web services, the Java Connector Architecture, JavaServer Pages, and more.
Generic work context implementation provides a mechanism for a resource adapter to control the contexts in which instances of work submitted by the resource adapter to the product work manager for execution are executed. By submitting a work instance that implements the WorkContextProvider interface, the resource adapter can propagate various types of context to the WebSphere Application Server. The application server then, if it supports the propagated context type, sets the provided context as the execution context of the work instance during its execution.
The connection management architecture for both relational and procedural access to enterprise information systems (EIS) is based on the Java EE Connector Architecture (JCA) specification. The Connection Manager (CM), which pools and manages connections within an application server, is capable of managing connections obtained through both resource adapters (RAs) defined by the JCA specification, and data sources defined by the JDBC Extensions Specification.