Adapter Pattern

2023-10-18 in Design Patterns

Adapter Pattern에 대해 설명하는 페이지입니다.

Environment

• Programming Language: Java

Index

• Index
• Introduction
• How to Use (Example)
• Comments

Introduction

• a.k.a
  • Wrapper
• Purpose
  • Permits classes with different interfaces to work together by creating a common object by which they may communicate and interact.
• Use When
  • A class to be used doesn’t meet interface requirements.
• Mechanism
  • A client makes a request to the adapter by calling a method on it using the target interface.
  • The adapter translates the request into one or more calls on the adaptee using the adaptee interface.
  • The client receives the results of the call and never knows there is an adapter doing the translation.
• Motivation
  • A toolkit or class library may have an interface which is incompatible with an application’s interface we want to integrate.
  • It’s possible that we don’t have access to the source code of the toolkit or library.
  • Even if the source code is available, we may want to minimize the change.
• Summary
  • Converts the interface of a class into another interface clients expect.
  • Lets classes work together that couldn’t otherwise because of incompatible interfaces.
  • Class adapter and object adapter

How to Use (Example)

• Target Interface

  public interface Duck {
      public void quack();
      public void fly();
  }
  
  public class MallardDuck implements Duck {
      public void quack() {
          System.out.println("Quack.");
      }
      public void fly() {
          System.out.println("I'm flying.");
      }
  }
  

• Adaptee Interface

  public interface Turkey {
      public void gobble();
      public void fly();
  }
  
  public class WildTurkey implements Turkey {
      public void gobble() {
          System.out.println("Gobble.");
      }
      public void fly() {
          System.out.println("I'm flying.");
      }
  }
  

• Object Adapter

  public class TurkeyAdapter implements Duck {
      Turkey turkey; // adaptee
      public TurkeyAdapter(Turkey turkey) {
          this.turkey = turkey;
      }
      public void quack() {
          turkey.gobble();
      }
      public void fly() {
          for (int i = 0; i < 5; i++) {
              turkey.fly();
          }
      }
  }
  

Comments

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