org.apache.tapestry.ioc.def.ServiceDef Maven / Gradle / Ivy

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// Copyright 2006, 2007 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry.ioc.def;

import org.apache.tapestry.ioc.ObjectCreator;
import org.apache.tapestry.ioc.ServiceBuilderResources;

import java.util.Set;

/**
 * Service definition derived, by default, from a service builder method.
 */
public interface ServiceDef
{
    /**
     * Returns an {@link ObjectCreator} that can create the core service implementation.
     *
     * @param resources used to resolve dependencies of the service, or access its configuration
     * @return an object that can (later) be used to instantiate the service itself
     */
    ObjectCreator createServiceCreator(ServiceBuilderResources resources);

    /**
     * Returns the service id, derived from the method name or the unqualified service interface
     * name. Service ids must be unique among all services in all modules. Service ids
     * are used in a heavy handed way to support ultimate disambiguation, but their primary purpose
     * is to support service contribution methods.
     */
    String getServiceId();

    /**
     * Returns an optional marker annotation. Marker annotations are used to
     * disambiguate services; the combination of a marker annotation and a service type is expected
     * to be unique. The annotation is placed on the field or method/constructor parameter and the
     * service is located by combining the marker with service type (the parameter or field type).
     *
     * @return the annotation, or null if the service has no annotation
     */
    Set getMarkers();

    /**
     * Returns the service interface associated with this service. This is the interface exposed to
     * the outside world, as well as the one used to build proxies. In cases where the service is
     * not defined in terms of an interface, this will return the actual implementation
     * class of the service. Services without a true service interfaced are not proxied.
     */
    Class getServiceInterface();

    /**
     * Returns the lifecycle defined for the service. This is indicated by adding a
     * {@link org.apache.tapestry.ioc.annotations.Scope} annotation to the service builder method
     * for the service.
     * 
     * Services that are not proxied will ignore their scope; such services are always treated as
     * singletons.
     */
    String getServiceScope();

    /**
     * Returns true if the service should be eagerly loaded at Registry startup.
     *
     * @see org.apache.tapestry.ioc.annotations.EagerLoad
     */
    boolean isEagerLoad();
}