Registry Design Pattern

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What is the Registry Design Pattern?

The Registry design pattern belongs to the base patterns family in enterprise application architecture. In simple terms, a Registry is a well-known, global object that other objects can use to find common objects and services.

Instead of passing dependencies or shared objects across multiple layers through constructors and method arguments, a Registry acts as a centralized directory where common instances can be stored and looked up whenever needed.

Implementation & Structure

A Registry typically stores references as key-value pairs:

• Map-Based Storage: Behind the scenes, registries are usually backed by data structures such as a HashMap or LinkedHashMap.
• Singleton Lifecycle: Registries are commonly implemented using the Singleton Pattern to provide a single, globally accessible instance throughout the application.

Real-World Example: CustomerRegistry

Consider a CustomerRegistry storing active customer objects:

• Key-Value Mapping: The key is the CustomerID (e.g., 1, 2) and the value is the corresponding Customer object (such as John or David).
• Adding Objects: Components can register instances using a method like addCustomer(id, customerObject).
• Looking Up Objects: Any service requiring customer data simply calls getCustomer(1) to retrieve John's details without having to query the database or depend on tight coupling.

Watch Related Architecture Tutorials:

• 👉 Singleton Design Pattern Explained: Key Points and Benefits
• 👉 Base Design Pattern: A Comprehensive Overview
• 👉 Repository Design Pattern Explained

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Registry Design Pattern

See also:

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