登记式单例模式

package comhellojava;import java.util.HashMap;import java.util.Map;/** * @function 登记式单例模式  类似于spring里面的用法，将类名注册，下次从里面直接获取 * @author ylchou * @time 2012/08/28 * */public class Singleton {        private static Map<String, Singleton> map = new HashMap<String,Singleton>();    static{        Singleton singleton = new Singleton();        System.out.println("--------"+singleton.getClass().getName());                //把singleton实例 put 进 comhellojava.Singleton        map.put(singleton.getClass().getName(), singleton);    }        //protected 构造器//    protected Singleton(){//    }        private Singleton(){    }        //静态工厂方法 返回此类唯一的实例    public static Singleton getInstance(String name){        if(name == null){            name = Singleton.class.getName();            System.out.println("if name is null,->name=" + name);        }                if(map.get(name) == null){            try {                map.put(name, (Singleton) Class.forName(name).newInstance());            } catch (InstantiationException e) {                e.printStackTrace();            } catch (IllegalAccessException e) {                e.printStackTrace();            } catch (ClassNotFoundException e) {                e.printStackTrace();            }        }        return map.get(name);    }        public String about() {        return "登记式单例模式";    }    public static void main(String[] args) {        Singleton s = Singleton.getInstance(null);        Singleton s2 = Singleton.getInstance(null);        System.out.println(s);        System.out.println(s2);        System.out.println(s.about());    }}

/**
--------comhellojava.Singleton
if name is null,->name=comhellojava.Singleton
if name is null,->name=comhellojava.Singleton
comhellojava.Singleton@de6ced
comhellojava.Singleton@de6ced
登记式单例模式
 */