Getting started with design patterns in Java with Eunjong

Kakao internal developer training course!
Learn only carefully selected design patterns 🤓

Design patterns learned through real-life examples ✨

Why are many systems being developed in object-oriented programming languages? It is to make it more efficient to expand functions, change requirements, and maintain systems or solutions after they are developed. In order for these changes to be easy, proper object-oriented design must be done from the design stage. Learning design patterns will help you understand and apply various solutions for design.

This lecture is used as a video for training internal developers at Kakao . It was created to help those who know Java grammar but have difficulty with object-oriented design using classes learn through design patterns. There are 23 patterns introduced by GoF, but in this lecture, we will introduce only 16 patterns that are actually used a lot in the field and useful in practice . Please study only the patterns that are widely used and applied in other frameworks and libraries! Studying this will also help you understand the framework later.

I recommend this to these people 🙋‍♀️

For those who don't know how to do object-oriented programming

Developer job seekers or new or junior developers

Anyone who wants to experience OOP development using Java

For those who want to understand design principles before studying the framework

Learn things like this 🤓

- Learning example of Strategy pattern

1. What is the problem?

• First, let's explain what the problematic situation is that led to this pattern and what this pattern is designed to do and intended to improve.

2. Understanding patterns through class diagrams

• Learn how patterns are applied through class diagrams and realistic, easy-to-follow examples.

3. Applying patterns and refactoring through realistic examples

Preview of course reviews 📜

*This is feedback on external mentoring that the knowledge sharer went through in the same process.

What you'll learn 📚

1. What is a design pattern? What is refactoring?

2. Patterns for creating objects

• Factory Method - Object creation and refactoring using factories
• Abstract Factory - Create a set of instances by selecting a factory.
• Singleton - Create only one instance

3. Make it more flexible by separating the algorithm skeleton or function and implementation.

• Strategy - Separate policies or algorithms and allow for additional replacement as needed.
• Bridge - Separates the part where the function is declared from the various implementations and connects them through a bridge.
• Template Method - Fixed flow is defined as a template, and methods that can be implemented in various ways within it are implemented in subclasses.

4. Identify

• Decorator - Add various functions flexibly (Identify Object and Decorator)
• Composite - Identifies a simple object with a composite object that contains it.

5. Make it flexible by expressing the state as a class

• State - When class-wide functionality is determined based on multiple values of the state.
• Observer - When you need to notify changes to multiple objects (Observers) that depend on one object (Subject).

6. Make the complex simple

• Facade - Provide a single interface for clients to use easily.
• Mediator - Prevents multiple objects from communicating with each other and only communicates with one central object.

7. Patterns that move around the structure

• Iterator - Provide a uniform interface for how to iterate over an object.
• Visitor - Visits an object and performs a function.

8. How to control access

• Proxy - A delegate for a real object

9. Compatibility

• Adapter - Change the interface to what the client wants.

10. Command as an object

• Command - Encapsulates and processes tasks that need to be performed in a variety of ways into a consistent interface.

11. Smart life with design patterns

Expected Questions Q&A 💬

Introducing the knowledge sharer ✒️

I majored in computer engineering at Dongguk University and received a master's degree in computer engineering from Seoul National University. While working at the company, I worked on numerous development projects in languages such as Java, C, and C++, and gave lectures on Java, web, data structures and algorithms, mobile, and design patterns at Bit Computer and T Academy.

I taught programming classes for non-majors at Kookmin University and Kyunghee University, and taught Java programming and programming practice classes as a part-time professor at NHN NEXT. I worked as a developer for 10 years, so I know what's needed in the field, and I also taught for another 10 years, so I understand the minds of beginners.

My current main interest is to help people from all walks of life, from elementary school students to adults, to become interested in and study the wonderful world of programming. I am currently a mentor at Innovation Academy (42 Seoul).

History

• Innovation Academy (42 SEOUL) Mentor
• Author of 'Do It Java Programming Introduction' (Easy Publishing)
• Fast Campus, creator of Inflearn's popular Java programming course
• NHN NEXT part-time professor, Beat Education Center, TAcademy instructor
• Spectra Development Team Leader
• Modern Information Technology
• Master's degree in Computer Science from Seoul National University
• Bachelor of Computer Engineering, Dongguk University

Portfolio/Personal Videos

• Do it Java Programming Introduction Author
• Inflearn Do it Java Programming Introduction Course