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Core Components of the Strategy Pattern The Strategy pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. Its standard implementation includes three key elements: Context Class (Context): Holds a rfeerence to a strategy object, often delegating the algorithm's execution to it. Strategy Interface (Strat ...

Overview of Design Patterns Design patterns represent reusable, time-tested solutions to recurring software engineering challenges. By categorizing these patterns, developers achieve cleaner, more maintainable, and loosely coupled code. The Gang of Four (GoF) defined 23 classic design patterns, classified into three functional categories: Crea ...

The Builder pattern is particular effective when the goal is to assemble complex objects step-by-step. Below is a implementation tailored for constructing Elasticsearch search queries based on different search strategies. Filter Inetrface Definition interface QueryFilterStrategy { QueryBuilder assemble(); static void applyDefaultFilter ...

Chain of Responsibility Definition: Creates a chain of receiver objects for a request. This pattern decouples the sender of a request from its receivers. Use Cases: When more than one object may handle a request, and the handler is determined at runtime. Pros: Reduces coupling between the sender and the receivers. Allows dynamic composition of ...

Classic Implementation Definision The Builder Pattern decouples the construction of a complex object from its representation, allowing the same construction process to create different representations. Pattern Structure Abstract Builder (Builder): Defines an abstract interface for creating parts of a Product object. It specifies what needs to ...

Simple Factory Pattern Overview The Simple Factory Pattern decouples the client code from the object instantaition logic by centralizing creation inside a dedicated factory. The client requests objects from the factory instead of instantiating them directly, which improves maintainability and extensibility. A key limitation is that adding or mo ...

Aircraft Control System Scenario Consider an aircraft control system involving airplanes, control towers, and ground services. class Airplane { private ControlTower tower; private GroundService service; public Airplane(ControlTower t, GroundService g) { this.tower = t; this.service = g; } public void reques ...

In large-scale web applications, caching is a fundamental technique alongside asynchronous and parallel processnig. For externally exposed APIs, implementing caching is crucial to prevent repeated database queries that can lead to server instability. Below is a generic cache manager interface that defines the core operations for a caching syste ...

Composite Pattern Overview The Composite Pattern, also known as the Part-Whole pattern, is a structural design pattern that allows treating individual objects and compositions of objects uniformly. It achieves this by defining a common interface for both leaf nodes (individual objects) and composite nodes (containers that hold other objects), e ...

Instantiating classes directly via constructors often couples client code tightly with concrete implementation details. This friction becomes pronounced when objects require multi-step configuration, validation, or conditional setup based on runtime parameters. Instead of scattering initialization logic across multiple consumer classes, central ...