建造者模式(Builder)

建造者模式(Builder):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;它是当创建复杂对象的算法应该独立于该对象的组成部分以及它们的装配方式时适用的模式.

#include <iostream>
#include <vector>
using namespace std;

class ToyModel
{
public:
    ToyModel(){}
    virtual ~ToyModel(){}
    virtual void step1()=0;
    virtual void step2()=0;
    virtual void step3()=0;
    void setSequence(const vector<int>& sequence){
        mSequence = sequence;
    }
    void create()
    {
        for(vector<int>::const_iterator iter = mSequence.begin();iter!=mSequence.end();++iter)
        {
            if(*iter==1){
                step1();
            }else if(*iter==2){
                step2();
            }else if(*iter==3){
                step3();
            }
        }
    }

private:
    vector<int> mSequence;
};

class Toy1:public ToyModel
{
public:
    Toy1(){}
    ~Toy1(){}
    void step1(){cout << "step1" << endl;}
    void step2(){cout << "step2" << endl;}
    void step3(){cout << "step3" << endl;}
};

class ToyBuilder
{
public:
    ToyBuilder(){}
    virtual ~ToyBuilder(){}
    virtual void setSequence(const vector<int>& sequence)=0;
    virtual ToyModel* getModel()=0;
};

class Toy1Builder:public ToyBuilder
{
public:
    Toy1Builder()
    {
        mToy1 = new Toy1;
    }
    ~Toy1Builder()
    {

    }
    void setSequence(const vector<int> &sequence){
        mToy1->setSequence(sequence);
    }
    ToyModel* getModel(){
        return mToy1;
    }

private:
    Toy1* mToy1;
};

int main()
{
    ToyBuilder* toy1Builder = new Toy1Builder;
    vector<int> v;
    v.push_back(3);
    v.push_back(2);
    v.push_back(1);
    toy1Builder->setSequence(v);
    ToyModel* toy1 = toy1Builder->getModel();
    toy1->create();
}

step3
step2
step1