Web Service J2EE Library Optional Package

Understanding WebLogic Server Deployment 2-5

2.4.1 Enterprise Application

An Enterprise application consists of one or more of the following J2EE applications or modules: ■ Web applications ■ Enterprise Java Beans EJB modules ■ Resource adapter modules An Enterprise application is packaged as an archive file with an .ear extension, but is generally deployed as an exploded EAR directory. An exploded EAR directory contains all of the JAR, WAR, and RAR modules also in exploded format for an application as well as the XML descriptor files for the Enterprise application and its bundled applications and modules. See Developing Applications for Oracle WebLogic Server.

2.4.2 Web Application

A Web application always includes the following files: ■ A servlet or JSP page, along with any helper classes. ■ A web.xml deployment descriptor, a J2EE standard XML document that configures the contents of a WAR file. Web applications may also contain JSP tag libraries, static .html and image files, supporting classes and .jar files, and a weblogic.xml deployment descriptor, which configures WebLogic Server-specific elements for Web applications. See Developing Web Applications, Servlets, and JSPs for Oracle WebLogic Server.

2.4.3 Enterprise JavaBean

Enterprise JavaBeans EJBs are reusable Java components that implement business logic and enable you to develop component-based distributed business applications. EJB modules are packaged as archive files having a .jar extension, but are generally deployed as exploded archive directories. The archive file or exploded archive directory for an EJB contains the compiled EJB classes, optional generated classes, and XML deployment descriptors for the EJB. See Programming WebLogic Enterprise JavaBeans for Oracle WebLogic Server for more information on the different types of EJBs.

2.4.4 Resource Adapter

A resource adapter also referred to as a connector adds Enterprise Information System EIS integration to the J2EE platform. Connectors provide a system-level software driver that WebLogic Server can use to connect to an EIS. Connectors contain both the Java classes, and if necessary, the native components required to interact with the EIS. See Programming Resource Adapters for Oracle WebLogic Server.

2.4.5 Web Service

A Web Service is a set of functions packaged into a single entity that is available to other systems on a network, and can be shared by and used as a component of distributed Web-based applications. Web Services commonly interface with existing back-end applications, such as customer relationship management systems, order-processing systems, and so on. A Web Service module may include either Java classes or EJBs that implement the Web Service. Web Services are packaged either as Web Application archives WARs or EJB 2-6 Deploying Applications to Oracle WebLogic Server modules JARs depending on the implementation; typically the WAR or EJB JAR file is then packaged in an Enterprise application. See Getting Started With JAX-WS Web Services for Oracle WebLogic Server.

2.4.6 J2EE Library

A J2EE library is a standalone J2EE module, or multiple J2EE modules packaged in an Enterprise application EAR, that is registered with the J2EE application container as a shared library at deployment time. After a J2EE library has been registered, you can deploy Enterprise applications that reference the library in their weblogic-application.xml deployment descriptors. Each referencing application receives a copy of the shared J2EE library modules on deployment, and can use those modules as if they were packaged as part of the application itself. J2EE library support provides an easy way to share one or more J2EE modules among multiple Enterprise applications without physically adding the shared modules to each dependent application. The deployment files of a shared library resemble either a standard Enterprise application or J2EE module, as discussed in this section. Shared libraries differ from standard EARs and modules only by the contents of their MANIFEST.MF files. Creating Shared J2EE Libraries and Optional Packages in Developing Applications for Oracle WebLogic Server describes how to assemble and configure J2EE libraries, and how to configure Enterprise applications that utilize J2EE libraries. Section 6.11, Deploying Shared Java EE Libraries and Dependent Applications describes how to deploy J2EE libraries and Enterprise applications that reference J2EE libraries.

2.4.7 Optional Package

Optional packages provide similar functionality to J2EE libraries, allowing you to easily share a single JAR file among multiple applications. However, optional packages function as individual J2EE modules standalone or within an Enterprise application, rather than as an Enterprise application. For example, third-party Web Application Framework classes needed by multiple Web applications can be packaged and deployed in a single JAR file, and referenced by multiple Web application modules in the domain. Optional packages are delivered as basic JAR files that have no deployment descriptors. You simply designate the JAR as an optional package at deployment time, and WebLogic Server registers the file with the target servers you select. After the optional package has been registered, you can then deploy J2EE modules and applications that reference the optional package in their MANIFEST.MF files. Creating Shared J2EE Libraries and Optional Packages in Developing Applications for Oracle WebLogic Server describes how to assemble and configure optional packages, and how to configure J2EE modules that utilize optional packages. Section 6.11, Deploying Shared Java EE Libraries and Dependent Applications describes how to deploy optional packages and J2EE modules that reference optional packages.

2.4.8 JDBC, JMS, and WLDF Modules