org.apache.felix.eventadmin/src/main/java/org/apache/felix/eventadmin/impl/security/TopicPermissions.java

/*
 *   Copyright 2005 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.felix.eventadmin.impl.security;

/**
 * A <tt>TopicPermission</tt> factory. The factory is bound to a specific type (i.e.,
 * either PUBLISH or SUBSCRIBE) and subsequently allows to create new permission
 * objects by providing the topic. Note that the created permission objects most 
 * likely will be cached and that in case that a permission can not be created due
 * to missing security support by the framework (i.e, security is not supported at 
 * all) an instance of <tt>java.lang.Object</tt> will be returned. 
 * 
 * @author <a href="mailto:felix-dev@incubator.apache.org">Felix Project Team</a>
 */
public interface TopicPermissions
{
    /**
     * Get the type (i.e., PUBLISH or SUBSCRIBE) of the permission objects that this
     * factory will create.
     * 
     * @return The type of the permission objects that this factory will create.
     * 
     * @see org.osgi.service.event.TopicPermission#PUBLISH
     * @see org.osgi.service.event.TopicPermission#SUBSCRIBE
     */
    public String getType();
    
    /**
     * This method returns a <tt>TopicPermission</tt> object for the given topic and
     * the type (i.e., PUBLISH or SUBSCRIBE) of this factory. Note that this methods
     * returns an instance of <tt>java.lang.Object</tt> in case that a permission 
     * could not be created due to missing security support by the framework.
     *  
     * @param topic The targeted topic.
     * 
     * @return A <tt>TopicPermission</tt> for the given topic and the type of this
     *      factory or a <tt>java.lang.Object</tt> in case that the permission could 
     *      not be created due to missing security support by the framework.
     *
     * @see org.osgi.service.event.TopicPermission
     * @see org.osgi.service.event.TopicPermission#PUBLISH
     * @see org.osgi.service.event.TopicPermission#SUBSCRIBE
     */
    public Object createTopicPermission(final String topic);
}