java design patterns pdf

Common Java design patterns-adapter patterns The Adapter mode is introduced to solve the incompatibility mismatch problem. Definition: The adapter mode converts the excuse of a class into another interface that the customer expects, so that the classes that originally cannot work together due to interface incompatibili

parametric construct, generates an object A through the new keyword, and then produces a new object T by A.clone (), then the constructor is not used when the object is copied. Be executed. That is, only one construction method is executed during the copy process.Clone vs final two pair of enemies. The object's clone is caused by a conflict with the final property within the object. In the programmer class above, modify to private final address address; Remove Get,set method, proto.address= (Ad

Chapter 1 of design patterns-Abstract Factory patterns (Java implementation)"The last time was my fault. The author of bribery asked me to talk about it first. However, my wife and adults have a lot to do with me, this time, let me add the application scenarios that have not been completed last time." (After that, I to

Chapter 1 of design patterns-factory method patterns (Java implementation)"I come first", "No, husband, I come first !". I heard a few people from far away. Oh no, it's the factory method model and the abstract factory model. The couple are quarreling. nimei is not eating, not all come first (the world of food ~). "Abs

Structure mode, a total of seven kinds: Adapter mode, adorner mode, proxy mode, appearance mode, bridging mode, combined mode, enjoy the meta-mode.First, the adapter mode:The adapter pattern transforms the interface of a class into another interface that the client expects, in order to eliminate compatibility issues with classes caused by mismatched interfaces. There are three main categories: The adapter mode of the class, the adapter mode of the object, and the adapter mode of the interface. F

classProducterImplementsRunnable {PrivateSyncstack stack; publicproducter (syncstack Stack) { this. Stack =stack; } public voidRun () { for(inti = 0;i) {String Producter= "product" +i; Stack.push (producter); System.out.println ("produced:" +producter); Try{thread.sleep (200); } Catch(interruptedexception E) {//TODO auto-generated Catch blockE.printstacktrace (); } } }}Create a Consumer: public classConsumerImplementsRunnable {PrivateSyncstack stack; p

As the name implies, multiple cases are compared to a singleton pattern, which can have more than one finite instance, such as the following, can only have two instances.Import java.util.ArrayList;Import Java.util.Random;Class Multition{Private final static int max_number=2;private static arraylistprivate static int index=0;Private String Currentmultitioninfo;Static{for (int i=0;i{Index=i;Amultitionarraylist.add (New Multition ());}}Private Multition (){Currentmultitioninfo= "The current object

(); Ocar.excet (); }}Template method Pattern Applicable scenario One-time implementation of an invariant part of the algorithm, and the variable behavior is left to subclass to achieve. The public behavior in each subclass should be extracted and centralized into a common parent class to avoid code duplication. This is a good example of what Opdyke and Johnson described as "re-factoring to generalize." First identify the differences in the existing code and separate the differen

, filterinputstream,filteroutputstream Concretedecorate Specific Decorative roles: responsible for adding new responsibilities to component objects, Bufferedinputstream,bufferedoutputstream, etc. Advantages Extended object functionality is more flexible than inheritance and does not result in a dramatic increase in the number of classes. You can decorate an object multiple times, creating a combination of different behaviors and getting more powerful objects. The concre

Create bean Factory all useFactory methodFor the production of fixed products in the same grade structure support to increase any productAbstract FactoryAll products for the production of different product familiesAbstract product family can be added to the inability of the productPrototype mode (copy, clone)You need to implement the Cloneable interface using the Clone () method to copy a close () method such as a file streamCreating an object with new requires very tedious data preparation or

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

Java design mode, java design mode pdf This article is my learning notes, welcome to reprint, but please note the Source: http://blog.csdn.net/jesson20121020 One problem with the simple factory model in the previous section is that the creation of the class depends on the fa

(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

Java design mode, java design mode pdf This article is my learning notes, welcome to reprint, but please note the Source: http://blog.csdn.net/jesson20121020 Before looking at the basic principles of the design model, let's loo