Understanding Jooby Composition

Jooby is a web framework for Java that emphasizes modularity and simplicity. The concept of composing applications using Jooby allows developers to build applications in a more organized and manageable way.

Main Points

What is Composition?

• Definition: Composition in Jooby refers to the practice of breaking down applications into smaller, reusable components (modules).
• Purpose: This helps in managing complexity and promotes code reuse.

Key Concepts

• Modules:
  • Individual units of functionality that can be independently developed and tested.
  • Each module can have its own routes, filters, and services.
• Main Application:
  • The main application is where you combine all the modules.
  • It acts as an entry point for the application.
• Dependency Injection:
  • Jooby uses dependency injection to manage dependencies between modules.
  • This allows for easier testing and scalability.

Benefits of Composition in Jooby

• Maintainability: Smaller, focused modules are easier to maintain and understand.
• Reusability: Modules can be reused across different applications.
• Separation of Concerns: Each module can focus on a specific aspect of the application.

Example of Composition

Combining Modules in Main Application:

public class MyApp extends Jooby {
    {
        // Load UserModule
        install(new UserModule());
    }
}

Creating a Module:

public class UserModule extends Jooby {
    {
        path("/users", () -> {
            get(() -> "List of users");
        });
    }
}

Conclusion

Using composition in Jooby allows developers to build applications that are easier to manage, test, and scale. By organizing code into modules, developers can create cleaner and more efficient applications.