Chapter 8: Packaging and Deployment of Enterprise Application - Coggle…
Chapter 8: Packaging and Deployment of Enterprise Application
A deployment descriptor (DD) refers to a configuration file for an artifact that is deployed to some container/engine. In the Java Platform, Enterprise Edition, a deployment descriptor describes how a component, module or application (such as a web application or enterprise application) should be deployed.
client-known URL name
The client sees a URL for the servlet (in the HTML), but doesn’t really know how that servlet name maps to real directories and files back on the server. The public URL name is a fake name, made up for clients.
Deployer-known secret internal name
The <servlet-mapping> element associates the internal name with the
name known to the client
The <servlet> element associates the fully-qualified class name with
the internal name
Packaging Java EE applications
An EJB JAR file is portable
can be used
for various applications
To assemble a Java EE application, package one or more modules, such as EJB JAR files, into an EAR file, the archive file that holds the application
When deploying the EAR file that contains the enterprise bean's EJB JAR file, you also deploy the enterprise bean to GlassFish Server
A web module can be deployed as an unpacked file structure or can be packaged in a JAR file known as a Web Archive (WAR) file
contents and use of WAR files differ from those of JAR files, WAR file names use a war extension
The web module just described is portable, you can deploy it into any web container that conforms to the Java Servlet specification
Java EE application is packaged into one or more standard units for
deployment to any Java EE platform-compliant system.
Optional Deployment Descriptor
Once a Java EE unit has been produced, it is ready to be deployed.
Example of Deployment Tool
A Java EE application is delivered in a Java Archive (JAR)file, a Web Archive (WAR) file, or an Enterprise Archive(EAR) file
A WAR or EAR file is a standard JAR (.jar) file with a .war or .ear extension
Using JAR, WAR, and EAR files and modules makes it possible to assemble a number of different Java EE applications using some of the same components
No extra coding is needed; it is only a matter of assembling (or packaging) various Java EE modules into Java EE JAR, WAR, or EAR files