How To create a @Service Connector
This chapter explains how to create a class that is suitable for the @Service annotation used by commands.
The @Service annotation can be used to mark a service that should be injected.
A Connector is a special kind of service that takes care of communication with external applications.
1. Configure the Annotation Processor
The following shows the configuration of the annotation processor using Gradle.
dependencies {
annotationProcessor "de.asap.pak.core:pak-serviceprocessor:${pakVersion}" (1)
}
compileJava { (2)
options.compilerArgs.add("-Aversion=$project.version")
options.compilerArgs.add("-Agroup=$project.group")
options.compilerArgs.add("-Aname=$project.name")
options.compilerArgs.add("-Arequires=de.asap.ExampleConnector:$project.version")
}| 1 | Add the annotation processor for the desired pak-version. |
| 2 | Pass the required options to the annotation processor. |
2. Create a Connector
Listing 1. Example Connector Implementation
/**
* Implementation of IExampleConnector
*/
@PakService (1)
public class ExampleConnector implements IPakService { (2)
public ISampleService getSampleService(){
return new SampleService();
}
}| 1 | The @PakService Annotation marks a Java-Class as Service, which can be used via the Service Interpreter. |
| 2 | It is mandatory to implement IPakService otherwise the annotation processor will not be accept the class as an C. |
2.1. Hiding Implementation
Alternatively the implementation of the Connector can be hidden using an interface which will be implemented by the specific Connector class.
Listing 2. Example Connector Specification
/**
* IExampleConnector specification
*/
public interface IExampleConnector {
/**
* @return the provided sample service
*/
ISampleservice getSampleService();
}3. Requesting Credentials
Some external applications do require credentials to work properly.
A Connector can request credentials by implementing the ICredentialRequester interface.
Listing 3. Example Connector with ICredentialRequester
/**
* Implementation of ExampleConnector with ICredentialRequester
*/
@PakService
public class ExampleConnector implements ICredentialRequester, IPakService { (1)
@Override
public void switchUser(final Credentials credentials) {
// Implementation when needed
}
@Override
public void changeCredentials(final CredentialFilter filter) {
// Implementation when needed
}
@Override
public void setCredentialsProvider(final ICredentialProvider provider) {
// Implementation when needed
}
}| 1 | ICredentialRequester needs to be implemented to request credentials. |
4. Usage in a Command
How to use a Connector in commands can be be found here