Welcome to the Java Design Patterns Resource Center. In their book, Design Patterns, Elements of Reusable Object-Oriented Software, the “Gang of Four” (E. Gamma, R. Helm, R. Johnson, and J. Vlissides) describe 23 design patterns that provide proven architectures for building object-oriented software systems. In this resource center, you'll find discussions of many of these design patterns. You'll also learn how Java API packages take advantage of design patterns. The Java Design Patterns Resource Center includes links to:

• Java Design Patterns tutorials.
• Several Java Design Patterns books sample chapters including “Introduction to Design Patterns,” from Design Patterns Java Workbook, by Steven John Metsker, and “Design Patterns: Origin and History,” from Software Architecture Design Patterns in Java, by Partha Kuchana.
• A slide presentation entitled "Using Design Patterns in Java Application Development," by Michael P. Redlich.
• The article: "What Are Design Patterns?" by James W. Cooper.
• The Java Patterns and Object Oriented Design forum.
• Sun Microsystems Java Patterns page that includes patterns and code for Java applications.
• The Java BluePrints Patterns catalog.
• The J2EE Patterns mailing list.
• Download the Java Design Patterns API.
• “Overview of Design Patterns,” from Design Patterns in Java: A Catalog of Reusable Design Patterns Illustrated with UML, Second Edition, by Mark Grand.
• The J2EE patterns catalog, including sample code from the Java BluePrints catalog.
• Definitions and examples of many Java design patterns.
• Design patterns articles by David Geary.
• Sample discussions from Design Patterns: Elements of Reusable Object-Oriented Software, January 1995, by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides (available in the Rice University site).
• The free eBook, The Design Patterns Java Companion, by James W. Cooper.
• Java Design Patterns training courses, books and eBooks.
• Job sites where you can search for Java software development jobs.
• Pattern Languages of Programming (PLoP) Conferences in the USA and Europe.