org.seedstack.seed

Annotation Type Provide

@Target(value=TYPE)
 @Retention(value=RUNTIME)
 @Documented
 @Inherited
public @interface Provide

This annotation creates an injection binding when applied on a JSR-330 Provider. It is comparable to the Bind annotation but allow to specify the creation logic of the instance in the Provider.get() method. A provider is itself injectable so you can use any required dependency during the creation of the provided instance.

  @Provide
  public class Provider <SomeClass > {
      @Inject
      private SomeDependency someDependency;

      public SomeInterface get() {
          return new SomeClass(someDependency);
      }
  }

  @Inject
  SomeClass someClassInstance;
 

The Provide annotation allows to override any existing SeedStack binding. To do this, create a Provider producing the same type as the SeedStack binding you want to override (this is the type you use at the injection point) and set the override() boolean to true. The instance produced by your provider will replace the SeedStack one.

When a qualifier annotation is present on the implementation class, it is used to make the injection point more specific:

  @Qualifier
  @Retention(RetentionPolicy.RUNTIME)
  public interface  @SomeQualifier {...}

  @Bind(from = SomeInterface.class)
  @SomeQualifier
  public class SomeImplementation implements SomeInterface {...}

  @Inject
  @SomeQualifier
  SomeInterface someInterface;
 

When having multiple implementations of the same interface, using a different qualifier on each implementation allows to create multiple bindings. You can then choose the implementation by specifying the corresponding qualifier at injection point.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	override If true the binding will be defined as an overriding one, meaning that it will override an identical binding already defined.

Element Detail

override

public abstract boolean override

If true the binding will be defined as an overriding one, meaning that it will override an identical binding already defined. If false, the binding will defined as a normal one.

Returns:

if true the binding is an overriding binding, if false a normal binding.

Default:

false