001/*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License").  You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
010 * or http://forgerock.org/license/CDDLv1.0.html.
011 * See the License for the specific language governing permissions
012 * and limitations under the License.
013 *
014 * When distributing Covered Code, include this CDDL HEADER in each
015 * file and include the License file at legal-notices/CDDLv1_0.txt.
016 * If applicable, add the following below this CDDL HEADER, with the
017 * fields enclosed by brackets "[]" replaced with your own identifying
018 * information:
019 *      Portions Copyright [yyyy] [name of copyright owner]
020 *
021 * CDDL HEADER END
022 *
023 *
024 *      Copyright 2009-2010 Sun Microsystems, Inc.
025 *      Portions copyright 2012 ForgeRock AS.
026 */
027
028package org.forgerock.opendj.ldif;
029
030import java.io.Closeable;
031import java.io.IOException;
032import java.util.NoSuchElementException;
033
034import org.forgerock.opendj.ldap.Entry;
035
036/**
037 * An interface for reading entries from a data source, typically an LDIF file.
038 * <p>
039 * Implementations must specify the following:
040 * <ul>
041 * <li>Whether or not it is possible for the implementation to encounter
042 * malformed change records and, if it is possible, how they are handled.
043 * <li>Any synchronization limitations.
044 * </ul>
045 */
046public interface EntryReader extends Closeable {
047
048    /**
049     * Closes this entry reader if it is not already closed. Note that this
050     * method does not need to be called if a previous call of
051     * {@link #readEntry()} has returned {@code null}.
052     *
053     * @throws IOException
054     *             If an unexpected IO error occurred while closing.
055     */
056    @Override
057    void close() throws IOException;
058
059    /**
060     * Returns {@code true} if this reader contains another entry, blocking if
061     * necessary until either the next entry is available or the end of the
062     * stream is reached.
063     *
064     * @return {@code true} if this reader contains another entry.
065     * @throws IOException
066     *             If an unexpected IO error occurred.
067     */
068    boolean hasNext() throws IOException;
069
070    /**
071     * Reads the next entry, blocking if necessary until an entry is available.
072     *
073     * @return The next entry.
074     * @throws IOException
075     *             If an unexpected IO error occurred while reading the entry.
076     * @throws NoSuchElementException
077     *             If this reader does not contain any more entries.
078     */
079    Entry readEntry() throws IOException;
080}