Complete Java Design Patterns masterclass

Discover the singleton pattern by creating a single shared resource, like a network manager, and compare eager, static block, lazy, thread-safe, and build-time initializations.

learn to implement singleton patterns in java with lazy instantiation and thread-safe get instance, address multi-threading issues, and explore inner static class approach to avoid memory problems in legacy code.

Learn the factory method design pattern that hides creation logic, separates use from creation, and returns the implementation (pizza round or burrito cylinder) via a shape factory for clients.

Explore how the abstract factory adds a layer above the factory method, enabling a data source factory for database and network sources while keeping the client decoupled from implementations.

Learn how the builder pattern simplifies object creation when many parameters exist, using a Java apartment example to demonstrate optional parameters, fluent chaining, and reduced boilerplate.

Explore the prototype design pattern to clone objects via a common interface, ensuring deep copies of fields, with practical Java examples using car and bicycle prototypes.

Use the adapter pattern to convert database data into legacy third-party display data, bridging incompatible interfaces and enabling cross-system communication.

Learn the bridge pattern to convert inheritance to composition by decoupling shape and color and connect two orthogonal dimensions—phone os and applications—via interfaces and concrete implementations.

Explore the facade design pattern by encapsulating complex steps behind a simple interface, hiding memory management and setup from clients, and enabling a single access point for network operations.

Explore the decorator pattern, a wrapper that adds or overrides behavior of existing objects—without modifying them—via wrapping a normal coffee machine with an enhanced version.

Explore the composite design pattern for tree-structured data, where leaves and composites form a hierarchy, enabling operations like price calculation to traverse the entire tree.

Explore the proxy pattern: a proxy with the same interface caches access to a heavy operation and instantiates the real object once, with before and after behavior to improve efficiency.

Apply the flyweight design pattern to reduce memory footprint by sharing image data via a factory, using three fighter ranks and an army to render many sprites efficiently.

Explore the observer pattern as a subscription mechanism where an event manager notifies multiple listeners when an event becomes available, illustrated by an editor with open and save events.

Explore the chain of responsibility pattern by building a chain of handlers that process or modify a network request and pass it along with authentication, content type, and payload headers.

Explore the command design pattern by decoupling the graphical user interface from business logic with a command wrapper and a dedicated processor that executes queued commands.

Explore the strategy design pattern by implementing a context called executor and multiple print strategies to switch algorithms at runtime for different data presentations.

Explain the state design pattern as a finite state machine where an object's behavior changes with its state. Implement a Java game with four states and controlled transitions.

Explore the visitor design pattern by externalizing new functionality as a separate report generator that traverses existing contracts to produce monthly and yearly cost reports.

Learn the mediator design pattern by implementing a central mediator that coordinates a group chat, letting users communicate through the mediator and reducing direct dependencies.

Explore the memento design pattern to enable undo and redo by capturing and restoring state with a memento, originator, and caretaker.

Thank learners for taking this course and for engaging with the material. Apply the knowledge to improve your code, projects, and applications, and explore other software development courses.