Design Patterns - institutional model - decorative patterns

First, the basic concept

1, the decorative pattern refers to the case without changing the original class file and use inheritance, dynamic function expansion of an object.

2, decorative object contains a reference to a real object, it is critical.

3, the role:

     A: Role abstract component (Component): definition of an object interface or abstract class can be dynamically added to the responsibility of these objects.

     B: the role of specific components (ConcreteComponent): real objects are dynamically added responsibilities.

     C: abstract decorative role (Decorator): implements the Component interface used to extend the functionality of the Component class, but for the Component, it is without knowing of the existence of Decorator.

     D: Specific decorative role (ConcreteDecorator): dynamically add responsibilities object.

     E: Client (Client)

Second, Examples (of a simple implementation, the C is omitted)

     A: Role abstract component (Component):

. 1  Package comm.pattern.struct.decorator;
 2  
. 3  / ** 
. 4  * 
 . 5  * @Title: Component.java
 . 6  * @package: comm.pattern.struct.decorator
 . 7  * @Description: abstract construct, Yang Guo analog
 8  * @ author yangzhancheng
 . 9  * @ 16 March 2020: 12:00:38 aM
 10  *
 . 11   * / 
12 is  public  interface the Component {
 13 is      public  void Operation ();
 14 }

View Code

 

     B: the role of specific components (ConcreteComponent):

. 1  Package comm.pattern.struct.decorator;
 2  
. 3  public  class ConcreteComponent the implements the Component {
 . 4  
. 5      public  void Operation () {
 . 6          of System.out.print ( "Yang Guo, too name, change of the word, is Jin Yong" Condor Crazy "hero;" );
 7      }
 . 8  
. 9 }

View Code

 

     C: abstract decorative role (Decorator):

          Omitted.

     D: Specific decorative role (ConcreteDecorator):

     D-1：

 1 package comm.pattern.struct.decorator;
 2 
 3 /**
 4  * 
 5  * @Title: Decorator.java
 6  * @Package: comm.pattern.struct.decorator
 7  * @Description: 装饰类
 8  * @author yangzhancheng
 9  * @2020年3月16日:上午12:05:54
10  *
11  */
12 class DecoratorA implements Component
13 {
14     private Component component;   
15     
16     public DecoratorA(Component component)
17     {
 18 is          the this .component = Component;
 . 19      }   
 20 is      
21 is      public  void Operation ()
 22 is      {
 23 is          component.operation ();
 24          of System.out.print ( "tomb he had to be in the living dead, Yunvxinjing practiced;" );
 25      }
 26 }

View Code

     D-2:

 1 package comm.pattern.struct.decorator;
 2 
 3 /**
 4  * 
 5  * @Title: DecoratorB.java
 6  * @Package: comm.pattern.struct.decorator
 7  * @Description: 装饰类
 8  * @author yangzhancheng
 9  * @2020年3月16日:上午12:10:12
10  *
11  */
12 class DecoratorB implements Component {
13     
14     private Component component;
15 
16     public DecoratorB(Component component) {
17         this= .component Component;
 18 is      }
 . 19  
20 is      public  void Operation () {
 21 is          component.operation ();
 22 is          of System.out.print ( "He had a brother carving" );
 23      }
 24 }

View Code

 

     E: Client (Client)

. 1  Package comm.pattern.struct.decorator;
 2  
. 3  / ** 
. 4  * 
 . 5  * @Title: Client.java
 . 6  * @package: comm.pattern.action.templateMethod
 . 7  * @Description: This document describes what
 8  * @ author yangzhancheng
 . 9  * @ 1 March 2020: PM 4:47:17
 10  *
 . 11   * / 
12 is  public  class Client {
 13 is  
14      public  static  void main (String [] args) {
 15  
16          the Component Component = new new ConcreteComponent () ;
17         component.operation();
18         
19         System.out.println("\n---------------------------------");
20         Component partyComponentDec = new DecoratorA(component);
21         partyComponentDec.operation();
22 
23         System.out.println("\n---------------------------------");
24         Component allComponent = new DecoratorB(new DecoratorA(new ConcreteComponent()));
25         allComponent.operation();
26     }
27 
28 }

View Code

 

Run output

Yang Guo, were over, change of character, Jin Yong is the "evil" of the hero;
 ---------------------------- ----- 
Yang Guo, were over, change of character, Jin Yong is the "evil" of the hero; he stayed in the tomb of the living dead, practiced Yunvxinjing;
 ---------- ----------------------- 
Yang Guo, were over, change of character, Jin Yong is the "evil" of the hero; his tomb in the Land of the Dead He stayed, practiced Yunvxinjing; he had an eagle brother

 

Third, the summary

    IO operation flow is typical of decorative patterns. Subsequent posted source code.