design mode (enjoy meta mode)

The enjoy meta-mode can be understood as a cache of objects, and all objects are managed by building a single-element factory.

The code is as follows:

• Flyweight the interface of the sharing element

 Public Interface Flyweight {    publicvoid  doAction ();}

• Flyweightimpl specific shared class implementations

 Public class Implements flyweight{    @Override    publicvoid  doAction () {        System.out.println ("doAction");}    }

• Flyweightfactory Factory

 Public classFlyweightfactory {Private StaticMap<string, flyweight>flyweights=NewHashmap<string, flyweight>();  Public StaticFlyweight getflyweight (String key) {if(Flyweights.get (key) = =NULL) {flyweights.put (key,NewFlyweightimpl ()); }        return(Flyweight) flyweights.get (key); }     Public Static intGetSize () {returnflyweights.size (); }}

• APP Test class

 Public class App {    publicstaticvoid  main (string[] args) {        new flyweightfactory ();        Factory.getflyweight ("a"). DoAction ();        Factory.getflyweight ("B"). DoAction ();        Factory.getflyweight ("a"). DoAction ();                System.out.println (Factory.getsize ());}    }

• Output results

doactiondoactiondoaction2

design mode (enjoy meta mode)