Day 19. Integrating with External Resources

Yesterday, you learned about patterns and how they describe typical application development problems that you might face and how these patterns provide solutions to these problems. One problem that many application developers share is how to integrate a J2EE application with existing non-Java code, applications, or systems. Today's lesson introduces you to four possible solutions to this problem.

The first of these solutions is the J2EE Connector architecture, which allows you to connect to Enterprise Information Systems (EIS), such as Enterprise Resource Planning systems (ERP). Primarily, today's lesson focuses on this architecture, but it also shows you approaches to writing Java code that consumes non-Java code libraries (such as legacy C libraries) and consume remote objects, which are also not written in Java.

Today's lesson covers the following topics:

• Reviewing external resources and legacy systems

• Introducing the Connector architecture

• Connecting to legacy systems by using the Common Client Interface

• Introducing Java IDL and CORBA

• Working with RMI over IIOP

• Working with the Java Native Interface

• Reviewing integration technologies