Service Lifetimes in ASP.NET Core vs. Spring Boot

ASP.NET Core:

1. Transient:

• Description: Creates a new service instance every time it's required.
• Example: A logger that doesn't retain any state and simply logs messages.

  services.AddTransient<ILogger, ConsoleLogger>();        

2. Scoped:

• Description: Provides a unique instance for each web request. This is useful when a consistent service is required throughout the lifecycle of a single request.
• Example: A database context ensuring that data operations within a single web request use the same data connection.

  services.AddScoped<IDbContext, MyDbContext>();        

3. Singleton:

• Description: Uses a single instance for the whole application. Suitable for services that need to retain state or share resources across many operations.
• Example: A cache manager that stores and retrieves data for the entire application.

  services.AddSingleton<ICacheManager, MemoryCacheManager>();        

Spring Boot:

1. Singleton (Default):

• Description: Only one instance of the service is created and shared across the entire application. This is the default behavior unless specified otherwise.
• Example: A configuration loader that loads and caches configuration for the whole application.

@Component  
public class ConfigLoader { /* ... */ }        

2. Prototype:

• Description: A new instance is made every time the service is requested. Perfect for services that should not retain any state between uses.
• Example: A temporary file handler that manages temporary file operations without retaining any state.

@Component 
@Scope("prototype")
public class TempFileHandler { /* ... */ }        

3. Request:

• Description: A separate instance is provided for each HTTP request. Useful for web apps where certain data/services are unique to each request.
• Example: User profile loader that loads data specific to a user during a web request.

@Component
@Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
public class UserProfileLoader { /* ... */ }        

4. Session:

• Description: Creates an instance specific to a user session. Handy for services that need to track or manage data consistently across multiple requests from the same user.
• Example: A shopping cart that tracks items added by a user throughout their session.

@Component
@Scope(value = WebApplicationContext.SCOPE_SESSION, proxyMode = ScopedProxyMode.TARGET_CLASS)
public class ShoppingCart { /* ... */ }        

Navigating the waters of service lifetimes requires understanding and strategic choices. In both ASP.NET Core and Spring Boot, how we manage our services plays a pivotal role in the application's efficiency and responsiveness. Whether it's handling short-lived tasks or preserving state across requests, always choose the scope that aligns best with your objectives. Here's to building robust and scalable applications!

#NET #SpringBoot