001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.nntp;
019
020/**
021 * A placeholder interface for threadable message objects.
022 *
023 * @param <T> The Threadable implementation.
024 */
025public interface Threadable<T extends Threadable<T>> {
026
027    /**
028     * Tests whether this is a dummy instance.
029     *
030     * @return whether this is a dummy instance.
031     */
032    boolean isDummy();
033
034    /**
035     * Creates a dummy instance.
036     *
037     * @return a dummy instance.
038     */
039    T makeDummy();
040
041    /**
042     * Gets an ID.
043     *
044     * @return an ID.
045     */
046    String messageThreadId();
047
048    /**
049     * Gets reference strings.
050     *
051     * @return  reference strings.
052     */
053    String[] messageThreadReferences();
054
055    /**
056     * Sets the child instance.
057     *
058     * @param child  the child instance.
059     */
060    void setChild(T child);
061
062    /**
063     * Sets the next instance.
064     *
065     * @param next  the next instance.
066     */
067    void setNext(T next);
068
069    /**
070     * Gets the simplified subject.
071     *
072     * @return the simplified subject.
073     */
074    String simplifiedSubject();
075
076    /**
077     * Tests whether this is a reply.
078     *
079     * @return whether this is a reply.
080     */
081    boolean subjectIsReply();
082}