java设计模式——享元模式

package ch26;

public class User {
private String name;

public User(String name) {
this.name = name;
}

public String getName() {
return name;
}
}

package ch26;

public abstract class Website {
public abstract void use(User user);
}

package ch26;

public class ConcreteWebsite extends Website {
private String name;

public ConcreteWebsite(String name) {
this.name = name;
}
@Override
public void use(User user) {
System.out.println("网站分类:" + name + ",用户:" + user.getName());
}

}

package ch26;

import java.util.HashMap;
import java.util.Map;

public class WebsiteFactory {
private Map<String, Website> flyweights = new HashMap<String, Website>();

public Website getWebsiteCategory(String key) {
if (!flyweights.containsKey(key)) {
flyweights.put(key, new ConcreteWebsite(key));
}
return flyweights.get(key);
}

public int getWebsiteCount() {
return flyweights.size();
}
}

package ch26;

/**
* 享元模式
* @author Administrator
*
*/
public class Client {

/**
* @param args
*/
public static void main(String[] args) {
WebsiteFactory f = new WebsiteFactory();

Website fx = f.getWebsiteCategory("产品展示");
fx.use(new User("小菜"));

Website fy = f.getWebsiteCategory("产品展示");
fy.use(new User("大鸟"));

Website fz = f.getWebsiteCategory("产品展示");
fz.use(new User("娇娇"));

Website fl = f.getWebsiteCategory("博客");
fl.use(new User("老顽童"));

Website fm = f.getWebsiteCategory("博客");
fm.use(new User("桃谷六仙"));

Website fn = f.getWebsiteCategory("博客");
fn.use(new User("南海鳄神"));

System.out.println("得到网站分类总数:" + f.getWebsiteCount());
}

}

网站分类:产品展示,用户:小菜
网站分类:产品展示,用户:大鸟
网站分类:产品展示,用户:娇娇
网站分类:博客,用户:老顽童
网站分类:博客,用户:桃谷六仙
网站分类:博客,用户:南海鳄神
得到网站分类总数:2

public Website getWebsiteCategory(String key) {
if (!flyweights.containsKey(key)) {
flyweights.put(key, new ConcreteWebsite(key));
}
return flyweights.get(key);
}

public static Integer valueOf(int i) {
final int offset = 128;
if (i >= -128 && i <= 127) { // must cache
return IntegerCache.cache[i + offset];
}
return new Integer(i);
}