Spring 5 Design Patterns

Implementing the Decorator pattern

Let's look at the following code to demonstrate the Decorator design pattern.

Create a component class:

Following is the Account.java file:

    package com.packt.patterninspring.chapter3.decorator.pattern; 
    public interface Account { 
       String getTotalBenefits(); 
    } 

Create concrete components classes:

Following is the SavingAccount.java file:

    package com.packt.patterninspring.chapter3.decorator.pattern; 
    public class SavingAccount implements Account { 
      @Override 
      public String getTotalBenefits() { 
         return "This account has 4% interest rate with per day           $5000 withdrawal limit"; 
      } 
    } 

Let's create another concrete class for Account component:

Following is the CurrentAccount.java file:

 package com.packt.patterninspring.chapter3.decorator.pattern; ...