java design patterns book

implementation is packaged into a class, if there are many alternative strategies, then the number of these classes is very large.To recognize a policy pattern from a code perspective:(Zhao Yun with three tricks to solve the problem, there are three elements in this scene: Three ingenious tricks, one capsule, one Zhao Yun)1. First create a policy interface (contains an algorithm that can be executed by each of the tips)2. Then write three implementation classes, because there are three clever t

!OBSERVERLIST.CONTAINS (Observer)) {OBSERVERLIST.ADD (Observer);}}@Overridepublic void Delete (Observerinterface observer) {if (Observerlist.contains (Observer)) {OBSERVERLIST.REMOVE (Observer);}}@Overridepublic void Notifyobserver () {if (isnotify) {for (Observerinterface object:observerlist) {Object.update (mess);}}}@Overridepublic void givemess (String message) {if (mess.equals (message)) {Isnotify = false;} else {Mess = message;Isnotify = true;}}}Viewer interface:Package com.design2;Public

observer;/** * Specific observer classes, such as LV Zeng in the example, Zhang Wei is an example of the Observer * @author WL * */public class Concretewatcher implements watcher { String Watcheredname; String Name;public concretewatcher (String name,string watcheredname) {this.name=name;this.watcheredname= Watcheredname;} @Overridepublic void Updata (String str) {System.out.println (name+ "Heart secretly happy" Hey!!! The opportunity came, my "+watcheredname+" said she ' "+str+" ' "");}Package

);/** * update Price */ Food.setprice (1.5f);}}third, the application scenarioGUI frame, meteorological observation, etc.Iv. SummaryBe sure to call the Setchanged () method before notifying all observers to set the state of the observer to be changed so that notifyobservers () will not be updated with the Observer Update method. If there are different opinions or omissions in the above content, please give us some valuable suggestions or comments.Finally, you can try to use the following UML mod

(); } } } public class Mysubject extends Abstractsubject { @Override public void operation () { System.out.println ("Update self!"); Notifyobservers (); } } Test class: public class Observertest { public static void Main (string[] args) { Subject sub = new Mysubject (); Sub.add (New Observer1 ()); Sub.add (New Observer2 ()); Sub.operation (); } } Output:Update self!Observer1 has rece

to return a concreteproduct instance.Test code:1 Public classTest {2 3 Public Static voidMain (string[] args) {4Iworkfactory studentworkfactory =Newstudentworkfactory ();5 studentworkfactory.getwork (). DoWork ();6 7Iworkfactory teacherworkfactory =Newteacherworkfactory ();8 teacherworkfactory.getwork (). DoWork ();9 }Ten One}1 Public Interface iworkfactory {23work getwork (); 4 } 1 public interface work { 2 void DoWork (); 4 } 1 public class Studentworkfacto

The factory class pattern provides the pattern of creating a single class, while the builder pattern is to centralize the various products to manage, to create composite objects, so-called composite objects that refer to a class that has different properties, in fact the builder pattern is the combination of the previous abstract factory pattern and the last Test. Let's look at the code:As before, a sender interface, two implementation classes MailSender and Smssender. Finally, the Builder class

(String Person: This. Getfriends ()) {List.add (person); } //frend.setfriends (list); returnfrend; } Catch(clonenotsupportedexception e) {e.printstacktrace (); return NULL; } }} PackageChenyang;Importjava.util.ArrayList;Importjava.util.List;/*** Text of the test class * *@author65245 **/ Public classText { Public Static voidMain (string[] args) {//1. Create a direct assignment to the collectionPerson person =NewPerson (); ListNewArraylist(); List.add ("Hello"); List.add

Design patterns are specific solution patterns (routines) that can be reused for specific problems in a specific situation that is constantly emerging. According to the three categories of creation, structure and behavior, this paper summarizes the main points of use of 24 kinds of design

Bookstore Management SystemThe bookstore management system can be said to be a more classic example of design patterns and design ideas.This series will be divided into several sections on this transmission management system.Bookstore management system will be divided into: Users, books, purchase, sales and inventory of five modules, in addition to public package

What is the design pattern? In the process of Learning Object-oriented, we will always come into contact with the pattern from time to time! As our predecessors have mentioned, the design model is a summary of people's experience! In software development, we always encounter some reusable components,CodeSo that we can focus on Object-Oriented Reusable Technology. With the development of Reusable Technology,

used.Two main uses of design patterns in software development.A common platform for developersDesign patterns provide a standard terminology system and are specific to specific scenarios. For example, a singleton design pattern means using a single object so that all developers who are familiar with the singleton

Seven major design principles:1. Single Duty principle: one class is responsible for a duty.2, the Richter replacement principle: Subclasses can extend the function of the parent class, but cannot change the original function of the parent class.3, dependency inversion principle: The high-level module should not rely on the lower layer module, both should rely on its abstraction; abstraction should not depend on detail; detail should depend on abstrac

structure and content of the design pattern, so I should use actual examples to help me understand the design patterns. If you go back and read a book again, there will be a lot of questions, the feeling of another village. (Not even applause)In Java, the

Designing the design mode of Banqiao is the earliest introduction of the system in the domestic media (including books and websites). This series introduces pure for free dissemination (reprint this website article, please keep the author and the website), as far as possible concise, is easy to understand, but inevitably has the omission to ask the letter or the forum discussion, unceasingly consummates. The real mastery of

The design mode in Java Jive-Linux general technology-Linux programming and kernel information. The following is a detailed description. This article does not explain the design patterns in detail. It just uses Jive to look at the application of the design

Classification of plant design and design patterns: The factory model is divided into three categories in Java and mode:1) Simple Factory mode (simply Factory): not conducive to the production of products;2) Factory method mode (Factory): Also known as the polymorphism plant;3) Abstract Factory mode (abstract Factory):

Design Patterns : Design Patterns are a set of reusable, most well-known, categorized purposes, code design experiences that use design patterns to reuse code, make code easier for othe

privatized, other programs can no longer create the class object;2, create an object of this class in a class;3, define a method that returns the object so that other programs can get this type of object by means of the method. (Effect: controllable).How to describe things and how to describe them.Add the above three steps when you need to guarantee that the object of the thing is unique in memory.a hungry man: A single class enters the object, it has already created the object.Lazy Type: The s

First Lecture: 1. Object-oriented design patterns and principles Introduction to Design Patterns: Each pattern describes a problem that recurs around us, and the core of the solution to the problem.--christopher alexander{Architect} Software designers ' understanding of the concept of