Patterns Section Index

Session facade is one design pattern that is often used while developing enterprise applications. It is implemented as a higher level component (i.e.: Session EJB), and it contains all the iteract...more

The new book "Pattern-oriented Software Architecture Volume 2" ISBN 0471606952 has a chapter on the Reactor pattern. It falls under the general category of "Event Handling Patterns...more

I have written plenty of non-thread-safe Singletons but it wasn't until recently when I tracked it down that I realized that thread-safety could be a big problem. The problem is that in the typic...more

Yes, and this can be the preferred pattern in some cases.For example, suppose you were writing a supply chain management system for a retail chain. Each store object in your system generates item...more

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The MVC (Model View Controller) design pattern is a pattern/architecture that can be used by GUI's. It seperates the application's data, user interface and control logic into three separate entit...more

Is there a pattern to avoid many if else if / switch conditions Say I have a javaBean with 4 string attributes say XXX and also the corresponding setXXX() and getXXX() In my application I have an...more

JDO is a persistence technology that competes against entity beans in enterprise application development. It allows you to create POJOs (plain old java objects) and persist them to the database - ...more

A good suggestion would be using Delegation class PieceOfCode { public Object myMethod() {} } class EJBImpl ... { PieceOfCode poc = new PieceOfCode(); public Object myMethod() { ...more

[I need to generate unique id's that will be used for node 'ID' attribute values within XML documents. This id must be unique system-wide. The generator must be available to a number of servlets t...more

In start(), instead of always creating a new object, return the existing one if it exists or create a new one if it doesn't.

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Collaboration Patterns are repeatable techniques used by teams of people to help them work together (collaborate). Ellen Gottesdiener of EBG Consulting has created these patterns in order to help...more

The Java-specific patterns books are: Java Design Patterns: A Tutorial Patterns in Java, Volume 1 Patterns in Java, Volume 2 Concurrent Programming in Java , Second Edition: Design Principles an...more

TAO is The ACE ORB -- a CORBA ORB built using the ACE framework. TAO is an open-source, standards-based, middleware platform which targets real-time CORBA including jitter, latency, reliability,...more