Builder pattern-生成器模式
生成器（英：Builder）是一种设计模式，又名：建造模式，是一种对象构建模式。它可以将复杂对象的建造过程抽象出来（抽象类别），使这个抽象过程的不同实现方法可以构造出不同表现（属性）的对象。


参与者
Builder
创建对象的抽象接口。
Concrete Builder
提供Builder的实现。
Director
负责管理对象创建的正确顺序。I
Product
由Director使用Builder创建的最终对象。

Java代码

1. package com.sinosoft.train.gof.cp;
3. /** "Product"－建造的最终产品－比萨饼 */
4. class Pizza {
5. private String dough = "";
6. private String sauce = "";
7. private String topping = "";
9. public void setDough(String dough) {
10. this.dough = dough;
11. }
13. public void setSauce(String sauce) {
14. this.sauce = sauce;
15. }
17. public void setTopping(String topping) {
18. this.topping = topping;
19. }
21. @Override
22. public String toString() {
23. return dough + "-" + sauce + "-" + topping;
24. }
25. }
27. /** "Abstract Builder"－比萨饼抽象生成器 */
28. abstract class PizzaBuilder {
29. protected Pizza pizza;
31. public Pizza getPizza() {
32. return pizza;
33. }
35. public void createNewPizzaProduct() {
36. pizza = new Pizza();
37. }
39. public abstract void buildDough();
41. public abstract void buildSauce();
43. public abstract void buildTopping();
44. }
46. /** "ConcreteBuilder"－夏威夷人的比萨饼生成器 */
47. class HawaiianPizzaBuilder extends PizzaBuilder {
48. public void buildDough() {
49. pizza.setDough("cross");
50. }
52. public void buildSauce() {
53. pizza.setSauce("mild");
54. }
56. public void buildTopping() {
57. pizza.setTopping("ham+pineapple");
58. }
59. }
61. /** "ConcreteBuilder" －辛辣的比萨饼生成器 */
62. class SpicyPizzaBuilder extends PizzaBuilder {
63. public void buildDough() {
64. pizza.setDough("pan baked");
65. }
67. public void buildSauce() {
68. pizza.setSauce("hot");
69. }
71. public void buildTopping() {
72. pizza.setTopping("pepperoni+salami");
73. }
74. }
76. /** "Director" － 厨师 */
77. class Cook {
78. private PizzaBuilder pizzaBuilder;
80. public void setPizzaBuilder(PizzaBuilder pb) {
81. pizzaBuilder = pb;
82. }
84. public Pizza getPizza() {
85. return pizzaBuilder.getPizza();
86. }
88. public void constructPizza() {
89. pizzaBuilder.createNewPizzaProduct();
90. pizzaBuilder.buildDough();
91. pizzaBuilder.buildSauce();
92. pizzaBuilder.buildTopping();
93. }
94. }
96. /** A given type of pizza being constructed. */
97. public class Builder {
98. public static void main(String[] args) {
99. Cook cook = new Cook();
100. PizzaBuilder hawaiianPizzaBuilder = new HawaiianPizzaBuilder();
101. PizzaBuilder spicyPizzaBuilder = new SpicyPizzaBuilder();
103. cook.setPizzaBuilder(hawaiianPizzaBuilder);
104. cook.constructPizza();
106. Pizza hawaiian = cook.getPizza();
107. System.out.println(hawaiian);
108. cook.setPizzaBuilder(spicyPizzaBuilder);
109. cook.constructPizza();
111. Pizza spicy = cook.getPizza();
112. System.out.println(spicy);
113. }
114. }