1 #include <iostream> 2 #include <string> 3 #include <map> 4 #include <vector> 5 #include <iterator> 6 #include <algorithm> 7  8 using namespace std; 9 10 class User11 {12 public:13         User(string strName): m_strName(strName)14         {15 16         }17 18         string GetName() const19         {20                 return m_strName;21         }22 23 private:24         string m_strName;25 };26 27 class WebSite28 {29 public:30         virtual void Use(const User* stUser) = 0;31 32 };33 34 class ConcreteWebSite: public WebSite35 {36 public:37         ConcreteWebSite(string strName): m_strName(strName)38         {39 40         }41 42         virtual void Use(const User* stUser)43         {44                 cout<< "网站分类："<< m_strName<< "\t 用户："<< stUser->GetName()<< endl;45         }46 47 private:48         string m_strName;49 50 };51 52 class WebSiteFactory53 {54 55 public:56         WebSite* GetWebSiteCategory(string strKey)57         {58                 if (mapFlyWeights.find(strKey) != mapFlyWeights.end())59                 {60                         return mapFlyWeights[strKey];61                 }62                 else63                 {64                         mapFlyWeights.insert(pair<string, WebSite*>(strKey, new ConcreteWebSite(strKey)));65                         return mapFlyWeights[strKey];66                 }67         }68 69 private:70         map<string, WebSite*> mapFlyWeights;71 };72 73 int main(int argc, char* argv[])74 {75         WebSiteFactory* f = new WebSiteFactory();76 77         WebSite* fx = f->GetWebSiteCategory("产品展示");78         fx->Use(new User("小菜"));79 80 81         WebSite* fy = f->GetWebSiteCategory("产品展示");82         fy->Use(new User("大鸟"));83 84 85         WebSite* fz = f->GetWebSiteCategory("博客");86         fz->Use(new User("xxxxx"));87 88 89         WebSite* fm = f->GetWebSiteCategory("博客");90         fm->Use(new User("OOOOOO"));91 92         return 0;93 }94 95 [root@ ~/learn_code/design_pattern/22_fly_weight]$ ./flyWeight       96 网站分类：产品展示       用户：小菜97 网站分类：产品展示       用户：大鸟98 网站分类：博客   用户：xxxxx99 网站分类：博客   用户：OOOOOO