One of the design mode Java Editions: Observer mode

Recently, the design pattern has been more and more attention by enterprises and programmers, and as a beginner, I will learn the bit by post to the blog park, share ~

The Java.util package provides support for the observer pattern, and the following is a copy of the observer and observable that wrote my observer pattern code.

 Package Com.myobserver;  Public Interface Observer {    void  update (Observable obs, Object obj);}

 Package Com.myobserver;  Public Interface Observable {    publicvoid  addobserver (Observer obs);      Public void deleteobserver (Observer obs);      Public void notifyobservers (Object obj);}

 PackageCom.myobserver;Importjava.util.ArrayList;Importjava.util.List; Public classConcreteobservableImplementsObservable {List<Observer> list =NewArraylist<observer>(); @Override Public voidaddobserver (Observer obs) {//TODO auto-generated Method StubList.add (OBS); } @Override Public voiddeleteobserver (Observer obs) {//TODO auto-generated Method StubList.remove (OBS); } @Override Public voidnotifyobservers (Object obj) {//TODO auto-generated Method Stub         for(Observer observer:list) {observer.update ( This, obj); }    }}

 Package Com.myobserver;  Public class Implements Observer {    @Override    publicvoid  update (Observable obs, Object obj) {         // TODO auto-generated Method stub        System.out.println ("------------concreteobserver received update info"                + obj + "from" + Obs);}    }

 Package Com.myobserver;  Public class Implements Observer {    @Override    publicvoid  update (Observable obs, Object obj) {         //  TODO auto-generated method stub        System.out.println ("------------ ConcreteObserver2 received update info "                + obj +" from "+ Obs);}    }

 PackageCom.myobserver; Public classTest { Public Static voidMain (string[] args) {concreteobservable observable=Newconcreteobservable (); Concreteobserver Observer1=NewConcreteobserver (); ConcreteObserver2 Observer2=NewConcreteObserver2 ();        Observable.addobserver (Observer1);        Observable.addobserver (OBSERVER2); Observable.notifyobservers ("Send a Broacast"); }}

Output Result:------------Concreteobserver received update info Send a broacast  [email protected]------------ ConcreteObserver2 received update info Send a broacast  [email protected]

This is mainly to understand the concept of design patterns, so do not consider multithreading synchronization.

One of the design mode Java Editions: Observer mode