Hello dear friends. In this video, we will examine the packaging in Java EE. Let's begin. Components must be packaged in a standard formatted archive to be deployed in a container. Java SE defines Java archive files as having the file extension .jar and being used to compress many files such as Java classes, deployment descriptors, resources or external libraries into a single file, similar to the zip format. Java EE defines different types of modules that have their own packaging format based on this common jar format. An application client module contains Java classes and other resource files packaged in a jar file. This jar file can be executed in a Java SE environment or in an application client container. Like any other archive format, the jar file contains an optional META-INF directory for meta information describing the archive. The META-INF/MANIFEST.MF file is used to define extension and package-related data.

If deployed in an ACC, the deployment descriptor can optionally be located at META-INF application client.xml. An EJB module contains one or more sessions and/or message-driven beans known as MDBs packaged in a jar file. This package is also referred to as an EJB-jar file. It contains optional META-INF/EJB-jar.xml deployment descriptor and can be deployed only in an EJB container. A web application module contains servlets, JSPs, JSF pages, web services and other web-related files like HTML and X HTML pages, CSS, Javascripts, images, videos and so on. Since Java EE 6, a web application module can also contain EJB light beans. All of these artifacts are packaged in a jar file with the .war extension. Application client modules contain class files and optionally, an application client deployment descriptor. Application client modules are packaged as jar files with the .jar extension. Resource adapter modules contain all Java interfaces, classes, native libraries and optionally a resource adapter deployment descriptor.

Together, these implement the connector architecture for a particular EIS. Resource adapter modules are packaged as jar files with a .rar extension commonly referred to as war file or a web archive. The optional web deployment descriptor is defined in the WEB-INF/web.xml file. If the war file contains EJB light beans, an optional deployment descriptor can be set at WEB-INF/ejb-jar.xml. Dependent jar files are stored in the WEB-INF-lib directory while Java class files are kept in the WEB-INF classes directory. I'm hoping that we now have a better understanding of Java EE packaging. In the next video, we will examine the Java 6EE APIs. See you in the next video.