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@LiteService

Java command annotations are used for the developing Java commands in PAK. This chapter describes the functionality of the @LiteService annotation. It also gives an example of how you can use this annotation in your implementation.

1. Basics

The @LiteService annotation basically works like @Service. A LiteService is basically a class, which implements the marker-interface ILiteService. The respective class is mostly located in the same java module like the command itself. Also, its registered as a Java Service, using java.util.ServiceLoader. It was introduced to differentiate between a normal Service- and a LiteService-injection. If the usage of @Service is not wanted, or simply too expensive, an ILiteService can be injected, using @LiteService, which provides the option of creating utility-Services.

2. Usage

Like previously mentioned, Services must extend or implement ILiteService in order to be annotated by @LiteService. This class should then operate as a Service within the Command.

Listing 1 shows how to use the @LiteService annotation.

Listing 1. Example Command, using @LiteService
/**
 * @workflowDocu This is a sample-command
 */
@JavaCommand
@CommandGroup("Generic.Sample")
public class SampleCommand {
	/**
	 * @workflowDocu ICommandRestService injected as a LiteService in order to provide the functionality to
	 *                conduct simple rest-calls
	 */
	@LiteService (1)
	private ICommandRestService restService;


	/**
	 * @workflowDocu Store response in this map
	 */
	@Persistent(scope = FieldScope.WRITE_ONLY)
	private Map<String, Object> responseMap;

	@Run
    public void run() {

	    final IEndpointClientService endpointClientService = this.restService.createEndpointClientServiceFor("myRequesterId"); (2)
		endpointClientService.register(JacksonFeature.class);
		final Response response = endpointClientService.getBaseTarget().path("/service/rest/v1/tasks").request().get(); (3)
		this.responseMap = response.readEntity(new GenericType<>() {
		}); (4)
    }
}
1 Use of @LiteService, to inject an implementation of ILiteService.
2 Create an IEndpointClientService, using ICommandRestService, by passing specific requesterId.
3 Fetch response from IEndpointClientService.
4 Save response as map.