Skip to main content

​
Overview

Service is the abstract base class for all TNB services. It provides a common structure for managing accounts, clients, and validation components. Services implement JUnit 5 lifecycle callbacks for setup and teardown.

​
Class signature

public abstract class Service<A extends Account, C, V extends Validation> 
    implements BeforeAllCallback, AfterAllCallback
Package: software.tnb.common.service Type parameters:
  • A - Account type that extends Account
  • C - Client type (service-specific)
  • V - Validation type that extends Validation

​
Properties

​
account
A
The account instance containing credentials and connection details for the service
​
client
C
The client instance used to interact with the service
​
validation
V
The validation instance providing test utilities and assertion methods

​
Methods

​
account()

Returns the account instance for this service. The account is lazily initialized using AccountFactory. 
public A account()
​
return
A
The Account instance for this service
Example: 
Kafka kafka = ServiceFactory.create(Kafka.class);
KafkaAccount account = kafka.account();
String bootstrapServers = account.bootstrapServers();

​
client()

Returns the client instance for this service. 
protected C client()
​
return
C
The client instance for interacting with the service
This method is protected and typically used internally by service implementations.

​
validation()

Returns the validation instance for this service, which provides methods for testing and verification. 
public V validation()
​
return
V
The Validation instance for this service
Example: 
Kafka kafka = ServiceFactory.create(Kafka.class);
kafka.validation().createTopic("test-topic");

​
Lifecycle methods

Service implements JUnit 5 extension callbacks:

​
beforeAll(ExtensionContext)

Called before all tests. Override this method to set up the service (deploy containers, initialize clients, etc.). 
public void beforeAll(ExtensionContext extensionContext) throws Exception

​
afterAll(ExtensionContext)

Called after all tests. Override this method to clean up the service (stop containers, close connections, etc.). 
public void afterAll(ExtensionContext extensionContext) throws Exception

​
Implementation example

Here’s how to extend the Service class: 
public class Webhook extends Service<WebhookAccount, NoClient, WebhookValidation> {
    
    @Override
    public void beforeAll(ExtensionContext extensionContext) throws Exception {
        // Initialize the service
        validation = new WebhookValidation();
    }
    
    @Override
    public void afterAll(ExtensionContext extensionContext) throws Exception {
        // Clean up resources
        if (validation != null) {
            validation.cleanup();
        }
    }
}

​
Generic type resolution

The Service class uses reflection to automatically determine the generic type parameters at runtime. This enables:
  • Automatic account creation via AccountFactory
  • Type-safe client initialization
  • Proper validation instance creation
Account instances are created lazily on first access using the AccountFactory.

​
Common service patterns

public class SimpleService 
    extends Service<SimpleAccount, SimpleClient, SimpleValidation> {
    
    @Override
    protected SimpleClient client() {
        if (client == null) {
            client = new SimpleClient(account());
        }
        return client;
    }
    
    @Override
    public void beforeAll(ExtensionContext context) throws Exception {
        validation = new SimpleValidation(client());
    }
}

Build docs developers (and LLMs) love

Get started for freeTalk to us