Java Architecture tutorial

The key to an extensible Some rough guidelines:
More than 25 top-level classes will lead to problems Every use case should be able to be implemented using domain model methods J2EE supports extensibility because it is component-based and allows you to separate the roles of an app. JSPs can handle presentation. Servlets can handle routing, and EJBs can handle business logic. Performance Architectural performance is concerned with creating an architecture that forces end-to-end performance. The purpose of an architecture that ensures performance is to control expensive calls and to identify bottlenecks. If you know the boundaries of the various parts of the system, the technologies, and the capabilities of the technologies you can do a good job of controlling performance. You want to minimize the number of network calls your distributed app makes – make a few “large” calls that get a lot of data vs. lots of calls that get small amounts of data. Try to minimize process-to-process calls because they are expensive. Use resource pooling to reduce the number of expensive resources that need to be created like network connections, database connections, etc. Performance involves minimizing the response time for a given transaction load. While a number of factors relating to the application design can affect this, adding additional resources in the following two ways, or a combination of both, can be used to good effect: Vertical scaling, which involves creating additional application server processes on a single physical machine in order to provide multiple thread pools, each corresponding to the JVM associated with each application server process. Horizontal scaling, which