23中设计模式

责任链

Interface Filter{

void doFilter(HttpServletRequest request,HttpServletResponse response,Filter filter);

}

class MyFilter implement Filter{

void doFilter(HttpServletRequest request,HttpServletResponse response,Filter chain){

    ...........

   chain.doFilter(request,response,chain);

    ............

    }

}

class FilterChain implenent Filter{

 private List<Filter> list = new LinkList<Filter>();

public void addFilter(Filter filter){

    list.add(filter);
}

public void doFilter(HttpServletRequest request,HttpServletResponse response,Filter chain){

        if(list.size()>0){

       list.remove().doFilter(request,response,this);

      }

}

装饰模式

它是给一个对象增加一些新的功能，而且是动态的，要求装饰对象和被装饰对象实现相同的接口，装饰对象持有装对象的实例