Design Mode 8-builder Mode

The builder mode defines a specific object and is a collection of various attributes. To create an object, you can create a constructor that contains a specific constructor, but only provides one interface. The detailed constructor is implemented in a derived class.

Builder. H Content

  1 #ifndef Builder_H_H  2 #define Builder_H_H  3   4 #include <iostream>  5 #include <string>  6 #include <vector>  7 using namespace std;  8   9 class Product 10 { 11 public: 12     Product() {} 13     void display(){ 14         //cout << vecStr.size() << endl; 15         for(size_t i=0; i<vecStr.size(); ++i){ 16             cout << vecStr[i] << "  "; 17         } 18         cout << endl; 19     } 20     void addItem(string str) { vecStr.push_back(str); } 21 private: 22     vector<string> vecStr; 23 }; 24  25 class Builder 26 { 27 public: 28     Builder() {} 29     virtual Product* getProduct() = 0; 30     void Build(){ 31         buildItem1(); 32         buildItem2(); 33     } 34     virtual void buildItem1() = 0; 35     virtual void buildItem2() = 0; 36     virtual ~Builder() {} 37 }; 38  39  40 class BuilderOne : public Builder 41 { 42 public: 43     BuilderOne() { product = new Product(); } 44     virtual void buildItem1() { product->addItem("First"); } 45     virtual void buildItem2() { product->addItem("Second"); } 46     virtual Product* getProduct() { return product; } 47     void release(){ 48         if(product != NULL){ 49             delete product; 50             product = NULL; 51         } 52     } 53     virtual ~BuilderOne() { release(); } 54 private: 55     Product *product; 56 }; 57  58 class BuilderTwo : public Builder 59 { 60 public: 61     BuilderTwo() { product = new Product(); } 62     virtual void buildItem1() { product->addItem("A"); } 63     virtual void buildItem2() { product->addItem("B"); } 64     virtual Product* getProduct() { return product; } 65     void release(){ 66         if(product != NULL){ 67             delete product; 68             product = NULL; 69         } 70     } 71     virtual ~BuilderTwo() { release(); } 72 private: 73     Product *product; 74 }; 75  76 class Direct 77 { 78 public: 79     Direct() : builder(NULL) {} 80     void setBuilder(Builder *builder0){ 81         release(); 82         builder = builder0; 83     } 84     void Build(){ 85         builder->Build(); 86     } 87     Product* getProduct() { return builder->getProduct(); } 88     void release(){ 89         if(builder != NULL){ 90             delete builder; 91             builder = NULL; 92         } 93     } 94     ~Direct() { release(); } 95 private: 96     Builder *builder; 97 }; 98  99 void BuilderTest()100 {101     Builder *builder1 = new BuilderOne();102     Builder *builder2 = new BuilderTwo();103     Direct *direct = new Direct();104 105     direct->setBuilder(builder1);106     direct->Build();107     direct->getProduct()->display();108 109     direct->setBuilder(builder2);110     direct->Build();111     direct->getProduct()->display();112 113     delete direct;114 }115 116 #endif

Running result:

Design Mode 8-builder Mode