org.osgi.resource.Requirement Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2011, 2013). 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.resource;
import java.util.Map;
import org.osgi.annotation.versioning.ConsumerType;
/**
* A requirement that has been declared from a {@link Resource} .
*
*
* Instances of this type must be effectively immutable. That is, for a
* given instance of this interface, the methods defined by this interface must
* always return the same result.
*
* @ThreadSafe
* @author $Id: 252221aeaaf9b189eef6e0c3798d0076a0032242 $
*/
@ConsumerType
public interface Requirement {
/**
* Returns the namespace of this requirement.
*
* @return The namespace of this requirement.
*/
String getNamespace();
/**
* Returns the directives of this requirement.
*
* @return An unmodifiable map of directive names to directive values for
* this requirement, or an empty map if this requirement has no
* directives.
*/
Map getDirectives();
/**
* Returns the attributes of this requirement.
*
*
* Requirement attributes have no specified semantics and are considered
* extra user defined information.
*
* @return An unmodifiable map of attribute names to attribute values for
* this requirement, or an empty map if this requirement has no
* attributes.
*/
Map getAttributes();
/**
* Returns the resource declaring this requirement.
*
* @return The resource declaring this requirement. This can be {@code null}
* if this requirement is synthesized.
*/
Resource getResource();
/**
* Compares this {@code Requirement} to another {@code Requirement}.
*
*
* This {@code Requirement} is equal to another {@code Requirement} if they
* have the same namespace, directives and attributes and are declared by
* the same resource.
*
* @param obj The object to compare against this {@code Requirement}.
* @return {@code true} if this {@code Requirement} is equal to the other
* object; {@code false} otherwise.
*/
boolean equals(Object obj);
/**
* Returns the hashCode of this {@code Requirement}.
*
* @return The hashCode of this {@code Requirement}.
*/
int hashCode();
}