001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2009-2010 Sun Microsystems, Inc.
015 * Portions copyright 2012-2016 ForgeRock AS.
016 */
017
018package org.forgerock.opendj.ldif;
019
020import java.io.Closeable;
021import java.io.IOException;
022import java.util.NoSuchElementException;
023
024import org.forgerock.opendj.ldap.Entry;
025
026/**
027 * An interface for reading entries from a data source, typically an LDIF file.
028 * <p>
029 * Implementations must specify the following:
030 * <ul>
031 * <li>Whether it is possible for the implementation to encounter
032 * malformed change records and, if it is possible, how they are handled.
033 * <li>Any synchronization limitations.
034 * </ul>
035 */
036public interface EntryReader extends Closeable {
037
038    /**
039     * Closes this entry reader if it is not already closed. Note that this
040     * method does not need to be called if a previous call of
041     * {@link #readEntry()} has returned {@code null}.
042     *
043     * @throws IOException
044     *             If an unexpected IO error occurred while closing.
045     */
046    @Override
047    void close() throws IOException;
048
049    /**
050     * Returns {@code true} if this reader contains another entry, blocking if
051     * necessary until either the next entry is available or the end of the
052     * stream is reached.
053     *
054     * @return {@code true} if this reader contains another entry.
055     * @throws IOException
056     *             If an unexpected IO error occurred.
057     */
058    boolean hasNext() throws IOException;
059
060    /**
061     * Reads the next entry, blocking if necessary until an entry is available.
062     *
063     * @return The next entry.
064     * @throws IOException
065     *             If an unexpected IO error occurred while reading the entry.
066     * @throws NoSuchElementException
067     *             If this reader does not contain any more entries.
068     */
069    Entry readEntry() throws IOException;
070}