SPI (Service Provider Interface) is a standard Java mechanism for enabling service discovery and dynamic component loading. It facilitates loose coupling by separating service interface definitions from their concrete implementations, allowing runtime loading of providers without modifying the core...
The Singleton pattern ensures a class has only one instance and provides a global point of access to it. Instead of relying on global variables—which can be instantiated multiple times—the class itself controls the creation and storage of its sole instance, guaranteeing uniqueness. Class Structure T...
Consider a document editing application where users compose text but lack the ability to reverse accidental deletions. Without a mechansim to capture prior conditions, each modification permanently alters the working state. public class Draft { private StringBuilder manuscript = new StringBuilder();...
Simple Factory, Factory Method, and Abstract Factory are fonudational creational design patterns that manage object instantiation. Simple Factory centralizes creation logic, Factory Method delegates it to subclasses, and Abstract Factory handles families of related objects. Simple Factory Pattern Th...
Core Software Design Principles Open/Closed Principle Core Idea: Open for extension, closed for modification When extending application functionality, you should avoid modifying existing working production code. Instead, use abstractions (interfaces or abstract classes) to achieve pluggable behavior...
Proxy Pattern Acting as an intermediary control layer, the proxy pattern intercepts requests intended for target objects, routing them through surrogate instances rather than permitting direct access. This architectural approach enables the injection of pre-processing and post-processing logic—such...
Type Structural Difficulty ★☆☆☆☆ (Low) Definition Convert an interface in to another interface clients expect, enabling incompatible classes to collaborate. Also known as Wrapper, it encapsulates a target class with a new layer, embodying the principle: "No problem can't be solved by adding one...
The Proxy design pattern is a structural pattern that provides a surrogate or placeholder to control access to another object. It involves creating a representative class that manages interaction with a real subject, enabling additional functionality like access control, lazy initialization, or logg...