Decorator Pattern details and code examples of Java design patterns

Decorator mode can dynamically add capabilities to existing objects. Next, I will use a simple example to demonstrate how to use decorator mode in a program.

1. Decorator mode

Let's assume that you are looking for a girlfriend. There are many girls from different countries, such as the United States, China, Japan, France, etc. each of them has different personalities and interests. If such a situation needs to be simulated in the program, assuming that each girl is a Java class, there will be thousands of classes, which will cause the expansion of classes, Moreover, the scalability of such a design will be poor. Because if we need a new girl, we need to create a new Java class, which actually violates the OCP (open to extension and close to modification) principle that needs to be followed in program development. Let's redo another design to make each personality or interest become a decoration, so that it can be dynamically added to each girl.

2. Class diagram structure

3. Decorator mode example code

Girl. java