建造者模式是對象的創建模式，可以將一個對象的內部表現和生成過程分割開來，從而使一個建造過程具有生成不同內部表現的對象的功能。

適用場景：RPG中遊戲角色、視頻播放軟件

比如進入RPG遊戲創建角色，先創建角色的模型、再創建角色的職業、再創建角色的性別等

 1 //RPG角色的對應類
 2 public class BRPGRole {
 3 
 4     private String model;
 5     private String career;
 6     private String sex;
 7     
 8     public String getModel() {
 9
 
         return model;
10     }
11     public void setModel(String model) {
12         this.model = model;
13     }
14     public String getCareer() {
15         return career;
16     }
17     public void setCareer(String career) {
18         this.career = career;
19     }
20     public String getSex() {
 
21         return sex;
22     }
23     public void setSex(String sex) {
24         this.sex = sex;
25     }
26     
27 }
28 
29 public interface Builder {
30 
31     public void buildModel();
32     public void buildCareer();
33     public void buildSex();
34     public BRPGRole getResult();
35     
36
 
 }
37 
38 //孫悟空RPG角色的創建類
39 public class WukongBuilder implements Builder {
40 
41     private BRPGRole product = new BRPGRole();
42     
43     @Override
44     public void buildModel() {
45         product.setModel("他的模型是孫悟空");
46     }
47 
48     @Override
49     public void buildCareer() {
50         product.setCareer("他的職業是妖魔");
51     }
52 
53     @Override
54     public void buildSex() {
55         product.setSex("他的性別是男");
56     }
57 
58     @Override
59     public BRPGRole getResult() {
60         return product;
61     }
62 
63 }
64 
65 public class BuilderGod {
66 
67     private Builder builder;
68     
69     public BuilderGod(Builder builder){
70         this.builder = builder;
71     }
72     
73     public void construct(){
74         builder.buildModel();
75         builder.buildCareer();
76         builder.buildSex();
77     }
78     
79 }
80 
81 public class BuilderMain {
82 
83     public static void main(String[] args) {
84         
85         Builder builder = new WukongBuilder();
86         BuilderGod builderGod = new BuilderGod(builder);
87         builderGod.construct();
88         BRPGRole role = builder.getResult();
89         System.out.println(role.getModel());
90         System.out.println(role.getCareer());
91         System.out.println(role.getSex());
92         
93     }
94 
95 }

輸出：

他的模型是孫悟空
他的職業是妖魔
他的性別是男

建造者模式