Chapter 6 Creating J2EE Applications for BEA WebLogic

Overview

PowerDesigner supports features like Object/Relational mapping (O/R mapping), UML Component Diagrams, and Enterprise Java Bean (EJB) generation.

There are several types of EJBs: Entity Beans, Session Beans and Message-Driven Beans.

Entity Beans are used for persistent objects. There are two types of persistence management: Container Managed Persistence (CMP) and Bean Managed Persistence (BMP). In CMP mode, the application server handles the persistence. An EJB deployer can define the O/R mapping information to tell the application server how to manage the persistence. In BMP mode, the persistence management code is defined in the EJB implementation class.

J2EE 1.3 has a new EJB 2.0 component model. The EJB 2.0 specification introduces a number of improvements: a better definition for CMP, local interfaces, an EJB Query Language (EJB-QL) and ejbSelect methods.

PowerDesigner supports UML object modeling and data modeling, allowing you to use the same tool to define objects, database schemas, O/R mappings and to generate EJBs. PowerDesigner adds O/R mapping definition and EJB generation. It fully supports the EJB 2.0 specification, and can support any application server supporting EJB 2.0.

With PowerDesigner, you can:

• Define EJBs using the UML Class Diagram and Component Diagram
• Generate or reverse engineer database using the Physical Data Model (PDM)
• Define O/R mapping
• Create CMP EJBs, BMP EJBs, Session Beans and Message Driven Beans
• Generate EJB source code and deployment descriptors
• Generate application server-specific descriptors
• Compile Java code and generate the EJB JAR file
• Run the J2EE verifier
• Deploy EJBs into an application server
• Customize the EJB code generator and the application server support

WebLogic Server 7.0 from BEA fully supports the EJB 2.0 specification. It is able to manage EJB persistence through their containers (CMP). It is usually preferable to let it manage the persistence because this tool provides optimized persistent management and better performance for large-scale applications.

Since PowerDesigner already has the O/R mapping metadata, we provide a way to export the metadata into a WebLogic server to make customers lives easier and to optimize persistence management for EJBs.

With PowerDesigner, you can:

• Define WebLogic specific O/R mappings
• Define WebLogic specific Extended Attributes
• Generate WebLogic descriptors including O/R mappings (weblogic-ejb-jar & weblogic-cmp-rdbms)
• Deploy EJBs into WebLogic Servers

This chapter describes PowerDesigner support for BEA WebLogic Server 7.0.

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