What is a resource adapter?
A resource adapter is a system-level software driver used by an application server or an application client to connect to an EIS. By plugging into an application server, the resource adapter collaborates with the server to provide the underlying mechanisms, the transactions, security, and connection pooling mechanisms. A resource adapter is used within the address space of the application server. What are the system contracts? The J2EE Connector Architecture’s system-level contracts define a “pluggability” standard between application servers and EISs. By adhering to the terms of these contracts when developing their components, an application server and an EIS know that connecting will be a straightforward operation of plugging in the resource adapter.
Let’s look closer at what adapters are. An adapter is a device that enables incompatible things, such as garden hoses or electrical connections, to connect and work together. In the world of business integration, you use a resource adapter to connect your business applications to diverse enterprise information systems so that they can send or retrieve information in a consistent manner. EISs include databases, enterprise resource planning systems, and mainframe transaction processing systems. A resource adapter is useful in two ways: • First, when you author your business applications, the resource adapter automatically discovers what is available in your back-end system and exposes it as services and business objects. The resource adapter defines a common interface that WebSphere Integration Developer uses to talk to your back-end system and discover the services and business objects.
A resource adapter is a software driver that an application server or an application client uses to connect to a specific EIS. An example of a resource adapter is a JDBC driver to connect to a relational database. Similarly, an ERP system or CRM system might include a resource adapter. Initial solutions to the need for resource adapters involved technologies that were proprietary and nonportable. Without the J2EE Connector Architecture, there would have to be a custom resource adapter to connect each type of application server to each type of EIS vendor. With the J2EE Connector Architecture acting as a standard resource adapter framework, each application server requires just a single implementation supporting the connector architecture specification, and each EIS requires just a single resource adapter that can plug in to any compliant application server.
Resource adapters allow your application to communicate with the enterprise information system (EIS). A resource adapter is a system-level software driver that is used by a Java application to connect to an EIS. The resource adapters reside on the application server and provide connectivity between the EIS, the application server, and the enterprise application. Applications deployed on the application server communicate with the resource adapter using the Common Client Interface (CCI). The RAR contains all the information necessary for installing, configuring, and running a resource adapter. Resource adapters comply with the J2EE Connector Architecture specification. In this lab, you are using IMS TM Resource Adapter to connect to IMS.
