Summary

Geronimo is a very large J2EE 1.4-compatible server. To create its J2EE personality, the developers of Geronimo brought together many service components from all over the ASF’s project tree. These service components can be classified according to the J2EE architectural tiers.

At the Web tier, the containers integrated into Geronimo are Jetty and Tomcat. You can select one or the other by downloading different distribution of Geronimo. These service components handle JSP, servlets, and popular developer frameworks such as JSF and Struts.

At the business tier, the containers integrated into Geronimo include OpenEJB and ActiveMQ. OpenEJB can host EJB written to the EJB 2 standard, including Component Managed Persistence (CMP2). ActiveMQ can host Message Driven Beans (MDBs), a type of EJB that responds to asynchronous incoming messages.

At the EIS tier of the J2EE architecture, Geronimo supports JCA 1.5 resource adapters. It leverages JDBC and can connect to any compliant RDBMS. Internally, Apache Derby is a Java-based RDBMS that is bundled. Connection to Message Queue service is also made possible via tight integration with ActiveMQ. JavaMail is also available at this tier for applications that interact with or generate email messages.

To support Web services, Geronimo has Apache Axis integrated. UDDI support, part of Geronimo’s feature set, is provided by jUUDI.

To interoperate with legacy systems, Geronimo has built-in CORBA interoperability, including CORBA’s CSIv2 security support.

Last, but not least, Geronimo features a client-side application client container that greatly simplifies the creation of J2EE client applications.

Geronimo provides running applications with a set of container services. These services include naming, security, transaction, manageability, and configuration management.

The entire J2EE 1.4 stack of components and services stands ready to serve your server-side needs in Geronimo. You may be curious to how the server works with all these integrated components. Many of your questions will be answered by the next chapter.

Chapter 5 covers the general architecture of the Geronimo server, together with the directory structure used by the server.