What is SOA?
Service-Oriented Architecture (SOA) is a design approach where software is composed of independent, loosely-coupled services that communicate via standard protocols.
Key Characteristics of SOA
- Loose Coupling
- Reusability
- Interoperability
- Autonomy
- Standardized Communication
- Discoverability
Example Scenario: Online Shopping System
We'll build 3 independent services using ASP.NET Core Web API.
- User Service: Manages users
- Product Service: Manages products
- Order Service: Places orders by calling other services
1. User Service
Dotnet new webapi -n UserService
// UserService/Controllers/UserController.cs
[Route("api/users")]
[ApiController]
public class UserController : ControllerBase
{
[HttpGet("{id}")]
public IActionResult GetUser(int id)
{
var user = new
{
Id = id,
Name = "John Doe",
Email = "[email protected]"
};
return Ok(user);
}
}
2. Product Service
Dotnet new webapi -n ProductService
// ProductService/Controllers/ProductController.cs
[Route("api/products")]
[ApiController]
public class ProductController : ControllerBase
{
[HttpGet("{id}")]
public IActionResult GetProduct(int id)
{
var product = new
{
Id = id,
Name = "Laptop",
Price = 1200.99
};
return Ok(product);
}
}
3. Order Service
Dotnet new webapi -n OrderService
// OrderService/Controllers/OrderController.cs
[Route("api/orders")]
[ApiController]
public class OrderController : ControllerBase
{
private readonly HttpClient _httpClient;
public OrderController(HttpClient httpClient)
{
_httpClient = httpClient;
}
[HttpPost]
public async Task CreateOrder(int userId, int productId)
{
var userResponse = await _httpClient.GetStringAsync($"http://localhost:5001/api/users/{userId}");
var user = JsonSerializer.Deserialize<dynamic>(userResponse);
var productResponse = await _httpClient.GetStringAsync($"http://localhost:5002/api/products/{productId}");
var product = JsonSerializer.Deserialize<dynamic>(productResponse);
var order = new
{
OrderId = 101,
User = user,
Product = product,
Status = "Order Placed"
};
return Ok(order);
}
}
Running the Services
- Update launchSettings.json with different ports: 5001, 5002, 5003
- Run each service using dotnet run --project <ServiceName>
Calling the Order API
POST http://localhost:5003/api/orders?userId=1&productId=101
{
"OrderId": 101,
"User": {
"Id": 1,
"Name": "John Doe",
"Email": "[email protected]"
},
"Product": {
"Id": 101,
"Name": "Laptop",
"Price": 1200.99
},
"Status": "Order Placed"
}
Benefits of SOA in .NET
- Independent Deployment
- Scalable Services
- Reusable APIs
- Cross-Platform Integration
Conclusion
SOA in .NET, especially with ASP.NET Core Web API, provides a modular, scalable, and loosely-coupled architecture. It’s ideal for enterprise-level systems with complex, evolving requirements.