#java

Articles tagged with #java

Design Patterns for Software Engineering
A Practical Guide for Low Level Design
Mar 4, 20265 min read35
Builder Design Pattern
Why Builder Pattern Exists When creating complex objects, constructors can become messy. Example: User user = new User("Souvik", 25, "Kolkata", "India", "Developer", true, false); Problems: Hard to
Mar 3, 20264 min read6
Decorator Design Pattern
Why Decorator Pattern Exists In real applications, we often need to add extra functionality to an object. Examples: Adding logging to a service Adding authentication to a controller Adding compress
Mar 3, 20264 min read4
Observer Design Pattern
Why Observer Pattern Exists In real systems, objects often depend on other objects’ state changes. Examples: When stock price changes → update dashboards When order is placed → send email + SMS + up
Mar 3, 20264 min read
Strategy Design Pattern
Why Strategy Pattern Exists In real applications, we often need to change behavior at runtime. Examples: Different payment processing logic Different discount calculation strategies Different sorti
Mar 3, 20264 min read2
Factory Design Pattern
Why Factory Pattern Exists When building applications, we often create objects based on some condition. Example: Payment type (UPI, Credit Card, NetBanking) Notification type (Email, SMS) Vehicle t
Mar 3, 20264 min read2