interface iplug{    void start();}class TV implements IPlug{    public void start(){        System.out.);    }}class AirCon implements IPlug{    public void start(){        System.out.println("AirCon start");    }} class Factory{    public static IPlug getInstance(String className){                if("TV".equals(className)){            return new TV();        }        else if("AirCon".equals(className)){            return new AirCon();        } else {            return null;        }    }}public class factoryDemo {    public static void main(String[] args) {        // TODO Auto-generated method stub        IPlug ip = Factory.getInstance("TV");        ip.start();        ip = Factory.getInstance("AirCon");        ip.start();    }}