org.osgi.service.blueprint.reflect.ServiceReferenceMetadata Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2008, 2009). All Rights Reserved.
*
* 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.osgi.service.blueprint.reflect;
import java.util.Collection;
/**
* Metadata for a reference to an OSGi service. This is the base type for
* {@link ReferenceListMetadata} and {@link ReferenceMetadata}.
*
* @ThreadSafe
* @version $Revision: 8415 $
*/
public interface ServiceReferenceMetadata extends ComponentMetadata {
/**
* A matching service is required at all times.
*
* @see #getAvailability()
*/
static final int AVAILABILITY_MANDATORY = 1;
/**
* A matching service is not required to be present.
*
* @see #getAvailability()
*/
static final int AVAILABILITY_OPTIONAL = 2;
/**
* Return whether or not a matching service is required at all times.
*
* This is specified in the availability attribute of the
* service reference.
*
* @return Whether or not a matching service is required at all times.
* @see #AVAILABILITY_MANDATORY
* @see #AVAILABILITY_OPTIONAL
*/
int getAvailability();
/**
* Return the name of the interface type that a matching service must
* support.
*
* This is specified in the interface attribute of the service
* reference.
*
* @return The name of the interface type that a matching service must
* support or null when no interface name is specified.
*/
String getInterface();
/**
* Return the value of the component-name attribute of the
* service reference. This specifies the id of a component that is
* registered in the service registry. This will create an automatic filter,
* appended with the filter if set, to select this component based on its
* automatic id attribute.
*
* @return The value of the component-name attribute of the
* service reference or null if the attribute is not
* specified.
*/
String getComponentName();
/**
* Return the filter expression that a matching service must match.
*
* This is specified by the filter attribute of the service
* reference.
*
* @return The filter expression that a matching service must match or
* null if a filter is not specified.
*/
String getFilter();
/**
* Return the reference listeners to receive bind and unbind events.
*
* This is specified by the reference-listener elements of the
* service reference.
*
* @return An immutable Collection of {@link ReferenceListener} objects to
* receive bind and unbind events. The Collection is empty if no
* reference listeners are specified for the service reference.
*/
Collection getReferenceListeners();
}