Programming Tutorials

Application Assembler in J2EE

By: aathishankaran in Java Tutorials on 2007-02-22  

The application assembler is the company or person who receives application component JAR files from component providers and assembles them into a J2EE application EAR file.

The assembler or deployer can edit the deployment descriptor directly or use tools that correctly add XML tags according to interactive selections. A software developer performs the following tasks to deliver an EAR file containing the J2EE application:

• Assembles EJB, JAR, and WAR files created in the previous phases into a J2EE application (EAR) file
• Specifies the deployment descriptor for the J2EE application
• Verifies that the contents of the EAR file are well formed and comply with the J2EE specification

Application Deployer and Administrator

The application deployer and administrator is the company or person who configures and deploys the J2EE application, administers the computing and networking infrastructure where J2EE applications run, and oversees the runtime environment. Duties include such things as setting transaction controls and security attributes and specifying connections to databases.

During configuration, the deployer follows instructions supplied by the application component provider to resolve external dependencies, specify security settings, and assign transaction attributes. During installation, the deployer moves the application components to the server and generates the container-specific classes and interfaces.

A deployer/system administrator performs the following tasks to install and configure a J2EE application:

• Adds the J2EE application (EAR) file created in the preceding phase to the J2EE server
• Configures the J2EE application for the operational environment by modifying the deployment descriptor of the J2EE application
• Verifies that the contents of the EAR file are well formed and comply with the J2EE specification
• Deploys (installs) the J2EE application EAR file into the J2EE server