盖个楼还要有图纸，你怎么可以不懂设计模式(三)

2024-02-14 11:26:28

前序：

相关引读

单例设计模式&工厂方法模式

传送门：https://www.cnblogs.com/powerZhangFly/p/13837675.html

模板方法模式&观察者模式&责任链模式

传送门：https://www.cnblogs.com/powerZhangFly/p/13800875.html

正文：

抽象工厂模式&建造者模式

抽象工厂模式

模式定义: 提供一个创建一系列相关或互相依赖对象的接口，而无需指定它们具体的类

代码示例：

 1 package com.zhangjiang.designpattern.abstractfactory; 
 2 
 3  /** 
 4  *  
 5  */ 
 6  public class AbstractFactoryTest { 
 7  public static void main(String[] args) { 
 8 IDatabaseUtils iDatabaseUtils=new OracleDataBaseUtils(); // 
 9  IConnection connection=iDatabaseUtils.getConnection(); 
10  connection.connect(); 
11  ICommand command=iDatabaseUtils.getCommand(); 
12  command.command(); 
13 
14 
15  } 
16  } 
17 
18  // 变化: mysql , oracle. ... 
19  // connection , command , 
20 
21  interface IConnection{ 
22  void connect(); 
23  } 
24  interface ICommand{ 
25  void command(); 
26  } 
27  interface IDatabaseUtils{ 
28  IConnection getConnection(); 
29  ICommand getCommand(); 
30  } 
31  class MysqlConnection implements IConnection{ 
32 
33  @Override 
34  public void connect() { 
35  System.out.println("mysql connected."); 
36  } 
37  }
38  class OracleConnection implements IConnection{ 
39 
40 @Override 
41  public void connect() { 
42  System.out.println("oracle connected."); 
43  } 
44  } 
45 
46 
47  class MysqlCommand implements ICommand{ 
48 
49  @Override 
50  public void command() { 
51  System.out.println(" mysql command. "); 
52  } 
53  } 
54 
55  class OracleCommand implements ICommand{ 
56 
57  @Override 
58  public void command() { 
59  System.out.println("oracle command."); 
60  } 
61  } 
62 
63  class MysqlDataBaseUtils implements IDatabaseUtils{ 
64 
65  @Override 
66  public IConnection getConnection() { 
67  return new MysqlConnection(); 
68  } 
69 
70  @Override 
71  public ICommand getCommand() { 
72  return new MysqlCommand(); 
73  } 
74  } 
75 
76  class OracleDataBaseUtils implements IDatabaseUtils{ 
77 
78  @Override80 public IConnection getConnection() { 
79  return new OracleConnection(); 
80  } 
81 
82  @Override 
83  public ICommand getCommand() { 
84  return new OracleCommand(); 
85  } 
86  }

View Code 应用场景: 程序需要处理不同系列的相关产品，但是您不希望它依赖于这些产品的具体类时，可以使用抽象工厂 优点: 1.可以确信你从工厂得到的产品彼此是兼容的。 2.可以避免具体产品和客户端代码之间的紧密耦合。 3.符合单一职责原则 4.符合开闭原则 JDK源码中的应用: java.sql.Connection java.sql.Driver

建造者模式

模式定义: 将一个复杂对象的创建与他的表示分离，使得同样的构建过程可以创建不同的表示

建造者模式实例：

  1  package com.zhangjiang.designpattern.builder; 
  2  /** 
  3  * 
  4  */ 
  5  public class BuilderTest { 
  6  public static void main(String[] args) { 
  7  // Product product=new Product( ); 
  8  // product.setCompanyName( "xxx" ); 
  9  // product.setPart1( "xxx" ); 
 10  // // ... 
 11  // 
 12  // // .... 
 13  // // .... 
 14  // 
 15 
 16  ProductBuilder specialConcreteProductBuilder=new SpecialConcreteProductB 
 17 uilder(); 
 18  Director director=new Director(specialConcreteProductBuilder); 
 19  Product product=director.makeProduct( "productNamexxx", "cn...", 
 20 "part1", "part2", "part3", "part4" ); 
 21  System.out.println(product); 
 22 
 23 
 24  } 
 25  } 
 26 
 27  interface ProductBuilder{ 
 28  void builderProductName(String productName); 
 29  void builderCompanyName(String companyName); 
 30  void builderPart1(String part1); 
 31  void builderPart2(String part2); 
 32  void builderPart3(String part3); 
 33  void builderPart4(String part4); 
 34 
 35  Product build(); 
 36  } 
 37 
 38  class DefaultConcreteProductBuilder implements ProductBuilder{ 
 39  private String productName; 
 40  private String companyName; 
 41  private String part1;42 private String part2; 
 42  private String part3; 
 43  private String part4; 
 44  @Override 
 45  public void builderProductName(String productName) { 
 46  this.productName=productName; 
 47  } 
 48 
 49  @Override 
 50  public void builderCompanyName(String companyName) { 
 51  this.companyName=companyName; 
 52  } 
 53 
 54  @Override 
 55  public void builderPart1(String part1) { 
 56  this.part1=part1; 
 57  } 
 58 
 59  @Override 
 60  public void builderPart2(String part2) { 
 61  this.part2=part2; 
 62  } 
 63 
 64  @Override 
 65  public void builderPart3(String part3) { 
 66  this.part3=part3; 
 67  } 
 68 
 69  @Override 
 70  public void builderPart4(String part4) { 
 71  this.part4=part4; 
 72  } 
 73 
 74  @Override 
 75  public Product build() { 
 76  return new Product( this.productName,this.companyName,this.part1,this.pa 
 77 rt2,this.part3,this.part4 ); 
 78  } 
 79  } 
 80 
 81  class SpecialConcreteProductBuilder implements ProductBuilder{82 private String productName; 
 82  private String companyName; 
 83  private String part1; 
 84  private String part2; 
 85  private String part3; 
 86  private String part4; 
 87  @Override 
 88  public void builderProductName(String productName) { 
 89  this.productName=productName; 
 90  } 
 91 
 92  @Override 
 93  public void builderCompanyName(String companyName) { 
 94  this.companyName=companyName; 
 95  } 
 96 
 97  @Override 
 98  public void builderPart1(String part1) { 
 99  this.part1=part1; 
100  } 
101  
102  @Override 
103  public void builderPart2(String part2) { 
104  this.part2=part2; 
105  } 
106  
107  @Override 
108  public void builderPart3(String part3) { 
109  this.part3=part3; 
110  } 
111  
112  @Override 
113  public void builderPart4(String part4) { 
114  this.part4=part4; 
115  } 
116  
117  @Override 
118  public Product build() { 
119  return new Product( this.productName,this.companyName,this.part1,this.p 
120 art2,this.part3,this.part4 ); 
121  }
122  } 
123  class Director{ 
124  
125  private ProductBuilder builder; 
126  
127  public Director(ProductBuilder builder) { 
128  this.builder=builder; 
129  } 
130  
131  public Product makeProduct(String productName, String companyName, Stri 
132 ng part1, String part2, String part3, String part4){ 
133  
134  builder.builderProductName(productName ); 
135  builder.builderCompanyName(companyName ); 
136  builder.builderPart1(part1 ); 
137  
138  builder.builderPart2(part2 ); 
139  builder.builderPart3(part3 ); 
140  builder.builderPart4(part4 ); 
141  
142  Product product=builder.build(); 
143  return product; 
144  
145  } 
146  
147  
148  } 
149  
150  class Product { 
151  
152  private String productName; 
153  private String companyName; 
154  private String part1; 
155  private String part2; 
156  private String part3; 
157  private String part4; 
158  // ...... 
159  
160  
161  public Product() { 
162  } 
163  public Product(String productName, String companyName, String part1, St 
164 ring part2, String part3, String part4) { 
165  this.productName=productName; 
166  this.companyName=companyName; 
167  this.part1=part1; 
168  this.part2=part2; 
169  this.part3=part3; 
170  this.part4=part4; 
171  } 
172  
173  public String getProductName() { 
174  return productName; 
175  } 
176  
177  public void setProductName(String productName) { 
178  this.productName=productName; 
179  } 
180  
181  public String getCompanyName() { 
182  return companyName; 
183  } 
184  
185  public void setCompanyName(String companyName) { 
186  this.companyName=companyName; 
187  } 
188  
189  public String getPart1() { 
190  return part1; 
191  } 
192  
193  public void setPart1(String part1) { 
194  this.part1=part1; 
195  } 
196  
197  public String getPart2() { 
198  return part2; 
199  } 
200  
201  public void setPart2(String part2) { 
202  this.part2=part2; 
203  }
204  
205  public String getPart3() { 
206  return part3; 
207  } 
208  
209  public void setPart3(String part3) { 
210  this.part3=part3; 
211  } 
212  
213  public String getPart4() { 
214  return part4; 
215  } 
216  
217  public void setPart4(String part4) { 
218  this.part4=part4; 
219  } 
220  
221  @Override 
222  public String toString() { 
223  return "Product{" + 
224  "productName='" + productName + '\'' + 
225  ", companyName='" + companyName + '\'' + 
226  ", part1='" + part1 + '\'' + 
227  ", part2='" + part2 + '\'' + 
228  ", part3='" + part3 + '\'' + 
229  ", part4='" + part4 + '\'' + 
230  '}'; 
231  } 
232  }

View Code 建造者模式与不可变对象配合使用

 1  public class ProductTest2 { 
 2  public static void main(String[] args) { 
 3  Product.Builder builder=new Product.Builder().productName( "xxxx" ).compa 
 4 nyName( "xxxxxx" ).part1( "xxxxx" ).part2( "xxxx" ); 
 5 
 6  // 
 7  builder.part3( "part3" ); 
 8  Product product=builder.build(); 
 9  System.out.println(product); 
10  } 
11 
12  } 
13  class Product { 
14 
15  private final String productName; 
16  private final String companyName; 
17  private final String part1; 
18  private final String part2; 
19  private final String part3; 
20  private final String part4; 
21  // ...... 
22 
23 
24 
25 
26  public Product(String productName, String companyName, String part1, Str 
27 ing part2, String part3, String part4) { 
28  this.productName=productName; 
29  this.companyName=companyName; 
30  this.part1=part1; 
31  this.part2=part2; 
32  this.part3=part3; 
33  this.part4=part4; 
34  } 
35 
36 
37 
38  static class Builder{ 
39 
40  private String productName; 
41  private String companyName; 
42  private String part1; 
43  private String part2; 
44  private String part3; 
45  private String part4; 
46 
47 
48  public Builder productName(String productName){ 
49  this.productName=productName;49 return this; 
50  } 
51  public Builder companyName(String companyName){ 
52  this.companyName=companyName; 
53  return this; 
54  } 
55  public Builder part1(String part1){ 
56  this.part1=part1; 
57  return this; 
58  } 
59  public Builder part2(String part2){ 
60  this.part2=part2; 
61  return this; 
62  } 
63  public Builder part3(String part3){ 
64  this.part3=part3; 
65  return this; 
66  } 
67  public Builder part4(String part4){ 
68  this.part4=part4; 
69  return this; 
70  } 
71 
72  Product build(){ 
73  // 
74  Product product=new Product( this.productName, this.companyName, this.pa 
75 rt1, this.part2, this.part3, this.part4 ); 
76  return product; 
77  } 
78 
79 
80  } 
81 
82 
83  @Override 
84  public String toString() { 
85  return "Product{" + 
86  "productName='" + productName + '\'' + 
87  ", companyName='" + companyName + '\'' + 
88  ", part1='" + part1 + '\'' + 
89  ", part2='" + part2 + '\'' +89 ", part3='" + part3 + '\'' + 
90  ", part4='" + part4 + '\'' + 
91  '}'; 
92  } 
93  }

View Code 应用场景 1.需要生成的对象具有复杂的内部结构 2.需要生成的对象内部属性本身相互依赖 3.与不可变对象配合使用优点： 1、建造者独立，易扩展。 2、便于控制细节风险。 Spring源码中的应用 org.springframework.web.servlet.mvc.method.RequestMappingInfo org.springframework.beans.factory.support.BeanDefinitionBuilder

码农公寓

前序：

单例设计模式&工厂方法模式

模板方法模式&观察者模式&责任链模式

正文：

抽象工厂模式&建造者模式

抽象工厂模式

建造者模式

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