Java Design Patterns

Java(tm) Design Patterns is exactly the tutorial resource you need. Gentle and clearly written, it helps you understand the nature and purpose of design patterns. It also serves as a practical guide to using design patterns to create sophisticated, robust Java programs.

This book presents the 23 patterns cataloged in the flagship book Design Patterns by Gamma, Helm, Johnson, and Vlissides. In Java(tm) Design Patterns, each of these patterns is illustrated by at least one complete visual Java program. This practical approach makes design pattern concepts more concrete and easier to grasp, brings Java programmers up to speed quickly, and enables you to take practical advantage of the power of design patterns.

Key features include:

• Introductory overviews of design patterns, the Java Foundation Classes (JFC), and the Unified Modeling Language (UML)
• Screen shots of each of the programs
• UML diagrams illustrating interactions between the classes, along with the original JVISION diagram files
• An explanation of the Java Foundation Classes that illustrates numerous design patterns
• Case studies demonstrating the usefulness of design patterns in solving Java programming problems
• A CD containing all of the examples in the book, so you can run, edit, and modify the complete working programs

After reading this tutorial, you will be comfortable with the basics of design patterns and will be able to start using them effectively in your day-to-day Java programming work.

Table of contents

Preface

Acknowledgments

Chapter 1 Introduction

Defining Design Patterns

The Learning Process

Studying Design Patterns

Notes on Object-Oriented Approaches

The Java Foundation Classes

Java Design Patterns

Chapter 2 UML Diagrams

Inheritance

Interfaces

Composition

Annotation

JVISION UML Diagrams

Visual SlickEdit Project Files

Chapter 3 The Factory Pattern

How a Factory Works

Sample Code

The Two Subclasses

Building the SimpleFactory

Factory Patterns in Math Computation

Thought Questions

Programs on the CD-ROM

Chapter 4 The Factory Method

The Swimmer Class

The Event Classes

Straight Seeding

Our Seeding Program

Other Factories

When to Use a Factory Method

Thought Question

Programs on the CD-ROM

Chapter 5 The Abstract Factory Pattern

A GardenMaker Factory

How the User Interface Works

Adding More Classes

Consequences of the Abstract Factory Pattern

Thought Question

Programs on the CD-ROM

Chapter 6 The Singleton Pattern

Creating a Singleton Using a Static Method

Exceptions and Instances

Throwing an Exception

Creating an Instance of the Class

Providing a Global Point of Access to a Singleton Pattern

The javax.comm Package as a Singleton

Other Consequences of the Singleton Pattern

Thought Question

Programs on the CD-ROM

Chapter 7 The Builder Pattern

An Investment Tracker

Calling the Builders

The List Box Builder

The Check Box Builder

Consequences of the Builder Pattern

Thought Questions

Programs on the CD-ROM

Chapter 8 The Prototype Pattern

Cloning in Java

Using the Prototype

Using the Prototype Pattern

Prototype Managers

Cloning Using Serialization

Consequences of the Prototype Pattern

Thought Question

Programs on the CD-ROM

Summary of Creational Patterns

Chapter 9 The Adapter Pattern

Moving Data between Lists

Using the JFC JList Class

Two-Way Adapters

Pluggable Adapters

Adapters in Java

Thought Question

Programs on the CD-ROM

Chapter 10 The Bridge Pattern

The Class Diagram

Extending the Bridge

Java Beans as Bridges

Consequences of the Bridge Pattern

Thought Question

Programs on the CD-ROM

Chapter 11 The Composite Pattern

An Implementation of a Composite

Computing Salaries

The Employee Classes

The Boss Class

Building the Employee Tree

Self-Promotion

Doubly Linked List

Consequences of the Composite Pattern

A Simple Composite

Composites in Java

Other Implementation Issues

Thought Questions

Programs on the CD-ROM

Chapter 12 The Decorator Pattern

Decorating a CoolButton

Using a Decorator

The Class Diagram

Decorating Borders in Java

Nonvisual Decorators

Decorators, Adapters, and Composites

Consequences of the Decorator Pattern

Thought Questions

Programs on the CD-ROM

Chapter 13 The Facade Pattern

Building the Facade Classes

Consequences of the Facade Pattern

Notes on Installing and Running the dbFrame Program

Thought Question

Programs on the CD-ROM

Chapter 14 The Flyweight Pattern

Discussion

Example Code

Flyweight Uses in Java

Sharable Objects

Copy-on-Write Objects

Thought Question

Programs on the CD-ROM

Chapter 15 The Proxy Pattern

Sample Code

Copy-on-Write

Enterprise Java Beans

Comparison with Related Patterns

Thought Question

Programs on the CD-ROM

Summary of Structural Patterns

Chapter 16 Chain of Responsibility Pattern

Applicability

Sample Code

The List Boxes

Programming a Help System

A Chain or a Tree?

Kinds of Requests

Examples in Java

Consequences of the Chain of Responsibility

Thought Questions

Programs on the CD-ROM

Chapter 17 The Command Pattern

Motivation

Command Objects

Building Command Objects

The Command Pattern

The Command Pattern in the Java Language

Consequences of the Command Pattern

Providing Undo

Thought Questions

Programs on the CD-ROM

Chapter 18 The Interpreter Pattern

Motivation

Applicability

Simple Report Example

Interpreting the Language

Objects Used in Parsing

Reducing the Parsed Stack

Implementing the Interpreter Pattern

Consequences of the Interpreter Pattern

Thought Question

Programs on the CD-ROM

Chapter 19 The Iterator Pattern

Motivation

Enumerations in Java

Sample Code

Filtered Iterators

Consequence of the Iterator Pattern

Composites and Iterators

Iterators in Java 1.2

Thought Question

Programs on the CD-ROM

Chapter 20 The Mediator Pattern

An Example System

Interactions between Controls

Sample Code

Mediators and Command Objects

Consequences of the Mediator Pattern

Single Interface Mediators

Implementation Issues

Programs on the CD-ROM

Chapter 21 The Memento Pattern

Motivation

Implementation

Sample Code

Consequences of the Memento Pattern

Thought Question

Programs on the CD-ROM

Chapter 22 The Observer Pattern

Watching Colors Change

The Message to the Media

The JList as an Observer

The MVC Architecture as an Observer

The Observer Interface and Observable Class

Consequences of the Observer Pattern

Thought Questions

Programs on the CD-ROM

Chapter 23 The State Pattern

Sample Code

Switching between States

How the Mediator Interacts with the StateManager

State Transitions

Mediators and the God Class

Consequences of the State Pattern

Thought Questions

Programs on the CD-ROM

Chapter 24 The Strategy Pattern

Motivation

Sample Code

The Context Class

The Program Commands

The Line and Bar Graph Strategies

Drawing Plots in Java

Consequences of the Strategy Pattern

Thought Question

Programs on the CD-ROM

Chapter 25 The Template Pattern

Motivation

Kinds of Methods in a Template Class

Template Method Patterns in Java

Sample Code

Templates and Callbacks

Consequences of the Template Pattern

Thought Question

Programs on the CD-ROM

Chapter 26 The Visitor Pattern

Motivation

When to Use the Visitor Pattern

Sample Code

Visiting the Classes

Visiting Several Classes

Bosses are Employees, Too

Catch-All Operations Using Visitors

Double Dispatching

Traversing a Series of Classes

Consequence of the Visitor Pattern

Thought Question

Programs on the CD-ROM

Chapter 27 The JFC, or Swing

Installing and Using Swing

Ideas behind Swing

The Swing Class Hierarchy

Chapter 28 Writing a Simple JFC Program

Setting the Look and Feel

Setting the Window Close Box

Making a JxFrame Class

A Simple Two-Button Program

More on JButton

Programs on the CD-ROM

Chapter 29 Radio Buttons and Toolbars

Radio Buttons

The JToolBar

JToggleButton

A Sample Button Program

Programs on the CD-ROM

Chapter 30 Menus and Actions

Action Objects

Design Patterns in the Action Object

Programs on the CD-ROM

Chapter 31 The JList Class

List Selections and Events

Changing a List Display Dynamically

A Sorted JList with a ListModel

Sorting More-Complicated Objects

Getting Database Keys

Adding Pictures in List Boxes

Programs on the CD-ROM

Chapter 32 The JTable Class

A Simple JTable Program

Cell Renderers

Rendering Other Kinds of Classes

Selecting Cells in a Table

Patterns Used in This Image Table

Programs on the CD-ROM

Chapter 33 The JTree Class

The TreeModel Interface

Programs on the CD-ROM

Summary

Chapter 34 Sandy and the Mediator

Chapter 35 Herb's Text Processing Tangle

Chapter 36 Mary's Dilemma