责任链设计模式-优快云博客

本文详细介绍了责任链设计模式的实现过程，并分析了其存在的性能缺陷。通过实例演示，阐述了如何在实际应用中进行优化，提高系统的响应效率。

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粗糙的实现了一个责任链设计模式的例子

#include <iostream>
#include <string>

using namespace std;


class Parent {
  public:
    Parent();
    virtual  ~Parent();
  private:
    Parent(Parent const&);
    Parent& operator = (Parent const&);
  public:
    void SetNextHander(Parent* hander);
    virtual int Handle(string request) = 0;
  protected:
    Parent* handler;
};


class FirstStep : public Parent {
  public:
    FirstStep(){}
    ~FirstStep(){}
  private:
    FirstStep(FirstStep const&);
    FirstStep& operator = (FirstStep const&);
  public:
    int Handle(string request);
};

class SecondStep : public Parent {
  public:
    SecondStep(){}
    ~SecondStep(){}
  private:
    SecondStep(SecondStep const&);
    SecondStep& operator = (SecondStep const&);
  public:
    int Handle(string request);
};

class ThirdStep : public Parent {
  public:
    ThirdStep(){}
    ~ThirdStep(){}
  private:
    ThirdStep(ThirdStep const&);
    ThirdStep& operator = (ThirdStep const&);
  public:
    int Handle(string request);
};

#include "responsibility.h"

Parent::Parent() {
  handler = NULL;
}

void Parent::SetNextHander(Parent* handler) { 
  this->handler = handler;
}

Parent::~Parent() {
  if(NULL != handler) {
    delete handler;
    handler = NULL;
  }
}

int FirstStep::Handle(string request) {
  if(request == "first") {
    cout<< "first process"<< endl;
  } else {
    if(NULL != handler)
      handler->Handle(request);
    else 
      cout<< "FirstStep final"<< endl;
  }
  return 0;
}

int SecondStep::Handle(string request) {
  if(request == "second") {
    cout<< "second process"<< endl;
    return 1;
  } else {
    if(NULL != handler)
      handler->Handle(request);
    else
      cout<< "SecondStep final" << endl;
  }
  return 0;
}

int ThirdStep::Handle(string request) {
  if(request == "third") {
    cout<< "third process"<< endl;
    return 1;
  } else {
    if(NULL != handler)
      handler->Handle(request);
    else
      cout<< "ThirdStep final" << endl;
  }
  return 0;
}

责任链设计模式的缺陷就是每个节点都会走一遍，影响性能，但便于扩展

转载于:https://my.oschina.net/hejiula/blog/112628