ServiceProvider (XAOS 0.13-SNAPSHOT API)

```
@Documented
@Repeatable(ServiceProviders.class)
@Retention(RUNTIME)
@Target(TYPE)
public @interface ServiceProvider
```
Declarative verification of a singleton service provider. By marking an implementation class with this annotation, you automatically verify that the implementation to be loaded by ServiceLoader is valid and that a corresponding provides … with directive is present into the module-info.java file. The service provider class must be public and have a public no-argument constructor.
Example of usage:
```
   package my.module;
   import my.module.spi.SomeService;
   import eu.ess.xaos.tools.annotation.ServiceProvider;

   @ServiceProvider(service=SomeService.class)
   public class MyService implements SomeService {
     ...
   }
```
Note: when using ServiceProvider the service() class must be listed in the module-info class inside a uses statement. Moreover a provides … with statement must also be added to declare the annotated class as provider for the parameter class.
Author:

claudio.rosati@esss.se

See Also:

NetBeans Lookup API

- Required Element Summary
  
  Required Elements
  Modifier and Type Required Element Description
  
  Class<?> service
  The interface (or abstract class) to register this implementation under.
- Optional Element Summary
  
  Optional Elements
  Modifier and Type Optional Element Description
  
  int order
  An optional number determining the load order of this service relative to others.

- Element Detail
  - service
```
Class<?> service
```
    The interface (or abstract class) to register this implementation under. It is an error if the implementation class is not in fact assignable to the interface.
    Requests to look up the specified interface through ServiceLoader.load(java.lang.Class) should result in this implementation.
    
    Returns:
    
    The service interface or abstract class.
- - order
```
int order
```
    An optional number determining the load order of this service relative to others. Lower-numbered services are returned in the lookup result first. Services with no specified position are returned last (ordered by name), followed by services registered using the standard Java mechanism.
    
    Returns:
    
    The load order of this service relative to others.
    
    Default:
    
    2147483646