设计模式C++学习笔记之十（Builder建造者模式）

建造者模式，将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。一段晦涩难懂的文字，实现创建不同表示的方法就是给创建的过程传入创建的参数。详细的还是看代码吧。

10.1.解释

main()，客户

CCarModel，产品模型

CBenzModel，奔驰模型

CBMWModel，宝马模型

ICarBuilder，建造者接口

CBenzBuilder，奔驰建造者

CBMWBuilder，宝马建造者

CDirector，导演

说明：CCarModel实现模板方法，Builder负责开始建造产品。建造产品时，构建的顺序由Director或main决定。

注意：建造者模式和抽象工厂非常类似。建造者更重视产品建造时的逻辑顺序，而抽象工厂更重视生产出不同型号的产品，抽象工厂不关心顺序。

看代码：

// Builder.cpp
#include "stdafx.h"
#include "CarModel.h"
#include "BenzModel.h"
#include "BMWModel.h"
#include "BenzBuilder.h"
#include "BMWBuilder.h"
#include "Director.h"
#include <vector>
#include <iostream>
using std::vector;
using std::string;
using std::cout;
using std::endl;

void DoBenzRun()　　//没有使用模式时，需要把步骤一条一条的传入模型。
{
    cout << "----------生成奔驰模型----------" << endl;
    CBenzModel *pBenz = new CBenzModel();
    vector<string> seq;
    seq.push_back("engine boom");//客户要求run的时候先发动引擎
    seq.push_back("start");//启动起来
    seq.push_back("stop");//开了一段就停下来

    pBenz->SetSequence(&seq);
    pBenz->Run();
    delete pBenz;
}

void DoBuilder()　　　　//使用模式后，由benzBuilder和bmwBuilder来生成，并且使用同样的创建顺序。
{
    cout << "----------用同一个顺序，生成模型----------" << endl;
    vector<string> seq;
    seq.push_back("engine boom");
    seq.push_back("start");
    seq.push_back("stop");

    CBenzBuilder benzBuilder;
    benzBuilder.SetSequence(&seq);
    CBenzModel *pBenz = dynamic_cast<CBenzModel*>(benzBuilder.GetCarModel());
    pBenz->Run();

    CBMWBuilder bmwBuilder;
    bmwBuilder.SetSequence(&seq);
    CBMWModel *pBmw = dynamic_cast<CBMWModel*>(bmwBuilder.GetCarModel());
    pBenz->Run();
}
void DoDirector()　　　　//使用指导者来封装创建的逻辑，把创建的顺序内聚在指导者类里面。
{
    cout << "----------批量生成模型----------" << endl;
    CDirector director;

    //1W辆A类型的奔驰车
    for(int i = 0; i < 2; i++)
        director.GetABenzModel()->Run();

    //100W辆B类型的奔驰车
    for(int i = 0; i < 2; i++)
        director.GetBBenzModel()->Run();

    //1000W辆C类型的宝马车
    for(int i = 0; i < 2; i++)
        director.GetCBMWModel()->Run();
}
int _tmain(int argc, _TCHAR* argv[])
{
    DoBenzRun();

    DoBuilder();

    DoDirector();

    _CrtSetDbgFlag(_CRTDBG_LEAK_CHECK_DF | _CRTDBG_ALLOC_MEM_DF);
    _CrtDumpMemoryLeaks();
    return 0;
}

//CarModel.h

#pragma once
#include <vector>
#include <iostream>
using std::vector;
using std::string;
class CCarModel
{
public:
    CCarModel(void);
    virtual ~CCarModel(void);
    void Run();
    void SetSequence(vector<string> *pSeq);
protected:
    virtual void Start() = 0;
    virtual void Stop() = 0;
    virtual void Alarm() = 0;
    virtual void EngineBoom() = 0;
private:
    vector<string> * m_pSequence;
};

//CarModel.cpp

#include "StdAfx.h"
#include "CarModel.h"
#include <vector>
#include <iostream>
using std::vector;
using std::string;
CCarModel::CCarModel(void)
{
}
CCarModel::~CCarModel(void)
{
}
void CCarModel::SetSequence(vector<string> *pSeq)
{
    m_pSequence = pSeq;
}
void CCarModel::Run()
{
    vector<string>::const_iterator it = m_pSequence->begin();
    for (; it < m_pSequence->end(); ++it)
    {
        string actionName = *it;
        if(actionName.compare("start") == 0)
        {
            Start();
        }
        else if(actionName.compare("stop") == 0)
        {
            Stop();
        }
        else if(actionName.compare("alarm") == 0)
        {
            Alarm();
        }
        else if(actionName.compare("engine boom") == 0)
        {
            EngineBoom();
        }
    }
}

//BenzModel.h

#pragma once
#include "carmodel.h"
class CBenzModel :
    public CCarModel
{
public:
    CBenzModel(void);
    ~CBenzModel(void);
protected:
    void Start();
    void Stop();
    void Alarm();
    void EngineBoom();
};

//BenzModel.cpp

#include "StdAfx.h"
#include "BenzModel.h"
#include <iostream>
using std::cout;
using std::endl;
CBenzModel::CBenzModel(void)
{
}
CBenzModel::~CBenzModel(void)
{
}
void CBenzModel::Start()
{
    cout << "奔驰发动..." << endl;
}
void CBenzModel::Stop()
{
    cout << "奔驰停车..." << endl;
}
void CBenzModel::Alarm()
{
    cout << "奔驰鸣笛" << endl;
}
void CBenzModel::EngineBoom()
{
    cout << "奔驰引擎声音是这样...." << endl;
}

//BMWModel.h

#pragma once
#include "carmodel.h"
class CBMWModel :
    public CCarModel
{
public:
    CBMWModel(void);
    ~CBMWModel(void);
protected:
    void Start();
    void Stop();
    void Alarm();
    void EngineBoom();
};

//BMWModel.cpp

#include "StdAfx.h"
#include "BMWModel.h"
#include <iostream>
using std::cout;
using std::endl;
CBMWModel::CBMWModel(void)
{
}
CBMWModel::~CBMWModel(void)
{
}
void CBMWModel::Start()
{
    cout << "宝马发动..." << endl;
}
void CBMWModel::Stop()
{
    cout << "宝马停车..." << endl;
}
void CBMWModel::Alarm()
{
    cout << "宝马鸣笛" << endl;
}
void CBMWModel::EngineBoom()
{
    cout << "宝马引擎声音是这样...." << endl;
}

//ICarBuilder.h

#pragma once
#include "CarModel.h"
#include <iostream>
#include <vector>
using std::string;
using std::vector;
class ICarBuilder
{
public:
    ICarBuilder(void)
    {
    }
    virtual ~ICarBuilder(void)
    {
    }
    virtual void SetSequence(vector<string> *pseq) = 0;
    virtual CCarModel * GetCarModel() = 0;
};
//BenzBuilder.h

#pragma once
#include "icarbuilder.h"
#include "CarModel.h"
#include <iostream>
#include <vector>
using std::string;
using std::vector;
class CBenzBuilder :
    public ICarBuilder
{
public:
    CBenzBuilder(void);
    ~CBenzBuilder(void);
    void SetSequence(vector<string> *pSeq);
    CCarModel * GetCarModel();
private:
    CCarModel *m_pBenz;
};
//BenzBuilder.cpp

#include "StdAfx.h"
#include "BenzBuilder.h"
#include "BenzModel.h"
CBenzBuilder::CBenzBuilder(void)
{
    m_pBenz = new CBenzModel();
}
CBenzBuilder::~CBenzBuilder(void)
{
    delete m_pBenz;
}
void CBenzBuilder::SetSequence(vector<string> *pSeq)
{
    m_pBenz->SetSequence(pSeq);
}
CCarModel * CBenzBuilder::GetCarModel()
{
    return m_pBenz;
}

//BMWBuilder.h

#pragma once
#include "icarbuilder.h"
#include "CarModel.h"
#include <iostream>
#include <vector>
using std::string;
using std::vector;
class CBMWBuilder :
    public ICarBuilder
{
public:
    CBMWBuilder(void);
    ~CBMWBuilder(void);
    void SetSequence(vector<string> *pSeq);
    CCarModel * GetCarModel();
private:
    CCarModel *m_pBMW;
};

//BMWBuilder.cpp

#include "StdAfx.h"
#include "BMWBuilder.h"
#include "BMWModel.h"
CBMWBuilder::CBMWBuilder(void)
{
    m_pBMW = new CBMWModel();
}
CBMWBuilder::~CBMWBuilder(void)
{
    delete m_pBMW;
}
void CBMWBuilder::SetSequence( vector<string> *pSeq )
{
    m_pBMW->SetSequence(pSeq);
}
CCarModel * CBMWBuilder::GetCarModel()
{
    return m_pBMW;
}

//Director.h

#pragma once
#include "BenzModel.h"
#include "BMWModel.h"
#include "BenzBuilder.h"
#include "BMWBuilder.h"
#include <vector>
using std::vector;
class CDirector
{
public:
    CDirector(void);
    ~CDirector(void);
    CBenzModel * GetABenzModel();
    CBenzModel * GetBBenzModel();
    CBMWModel * GetCBMWModel();
    CBMWModel * GetDBMWModel();
private:
    vector<string> * m_pSeqence;
    CBenzBuilder * m_pBenzBuilder;
    CBMWBuilder * m_pBMWBuilder;
};

//Director.cpp

#include "StdAfx.h"
#include "Director.h"
CDirector::CDirector(void)
{
    m_pBenzBuilder = new CBenzBuilder();
    m_pBMWBuilder = new CBMWBuilder();
    m_pSeqence = new vector<string>();
}
CDirector::~CDirector(void)
{
    delete m_pBenzBuilder;
    delete m_pBMWBuilder;
    delete m_pSeqence;
}
CBenzModel * CDirector::GetABenzModel()
{
    m_pSeqence->clear();
    m_pSeqence->push_back("start");
    m_pSeqence->push_back("stop");
    m_pBenzBuilder->SetSequence(m_pSeqence);
    return dynamic_cast<CBenzModel*>(m_pBenzBuilder->GetCarModel());
}
CBenzModel * CDirector::GetBBenzModel()
{
    m_pSeqence->clear();
    m_pSeqence->push_back("engine boom");
    m_pSeqence->push_back("start");
    m_pSeqence->push_back("stop");
    m_pBenzBuilder->SetSequence(m_pSeqence);
    return dynamic_cast<CBenzModel*>(m_pBenzBuilder->GetCarModel());
}
CBMWModel * CDirector::GetCBMWModel()
{
    m_pSeqence->clear();
    m_pSeqence->push_back("alarm");
    m_pSeqence->push_back("start");
    m_pSeqence->push_back("stop");
    m_pBMWBuilder->SetSequence(m_pSeqence);
    return static_cast<CBMWModel*>(m_pBMWBuilder->GetCarModel());
}
CBMWModel * CDirector::GetDBMWModel()
{
    m_pSeqence->clear();
    m_pSeqence->push_back("start");
    m_pBenzBuilder->SetSequence(m_pSeqence);
    return dynamic_cast<CBMWModel*>(m_pBMWBuilder->GetCarModel());
}

建造者模式属于创建型模式，主要关注创建的顺序，不同的顺序，生产的产品略有不同。