Facade门面，Mediator调停者，Decorator装饰器，责任链

Facade 门面#

• 对外，专业代办

Mediator 调停者#

• 部门内部打交道，从内部抽出一个部门来，这个部门就是调停者

 

对内和对外可以是一个人，心中无剑，手中有剑

Decorator 装饰器#

用聚合代替继承

 

责任链 ChainOfResponsibility#

• 封装变化

 

 

 

public class Main{
    public static void main(String[] args){
        Msg msg = new Msg();
        msg.setMsg("welcome");    
        
        FilterChain fc1 = new FilterChain();
        fc1.add(new HTMLFilter()).add(new SensitiveFilter());

        FilterChain fc2 = new FilterChain();
        fc2.add(new FaceFilter()).add(new UrlFilter());        

        fc.doFilter(msg);
        fc2.doFilter(msg);// 链条相连
        System.out.println(msg);
    }
}

class Msg{
    String name;
    String msg;
}

public String getMsg(){
    return msg;
}

public void setMsg(String msg){
    this.msg = msg;
}

public String toString(){
    return "Msg{" + "msg='" + msg + '\'' + '}';
}

interface Filetr{
    void doFilter(Msg m);
}

class HTMLFilter implements Filter{    
    public boolean doFilter(Msg m){
        String r = m.getMsg();
        r = r.replace('<', '[');
        r = r.replace('>', ']');
        m.setMsg(r);    
        return true;
    }    
}

class SensitiveFilter implements Filter{
    public boolean doFilter(Msg m){
        r = r.replaceAll("wel", "in");
        m.setMsg(r);    
        return false;
    }    
}

class FaceFilter implements Filter{
    public boolean doFilter(Msg m){
        r = r.replaceAll("wel", ":)");
        m.setMsg(r);    
        return false;
    }    
}

class UrlFilter implements Filter{
    public boolean doFilter(Msg m){
        r = r.replaceAll("wel", "http://");
        m.setMsg(r);    
        return false;
    }    
}

class SensitiveFilter implements Filter{
    public boolean doFilter(Msg m){
        r = r.replaceAll("wel", "in");
        m.setMsg(r);    
        return false;
    }    
}

class FilterChain{

    List<Filter> filters = new ArrayList<>();

    public FilterChain add(Filter f){
        filters.add(f);
        return this;
    }

    public boolean doFilter(Msg m){
        for(Filter f : filters){
            if(!f.doFilter(m)){
                return false;
            }
            return true;
        }
    }
}

class Request{
    String str;
}

class Response{
    String str;
}