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 *      http://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.pop3;
019
020/**
021 * POP3Command stores POP3 command code constants.
022 */
023
024public final class POP3Command {
025    /** Send user name. */
026    public static final int USER = 0;
027    /** Send password. */
028    public static final int PASS = 1;
029    /** Quit session. */
030    public static final int QUIT = 2;
031    /** Get status. */
032    public static final int STAT = 3;
033    /** List message(s). */
034    public static final int LIST = 4;
035    /** Retrieve message(s). */
036    public static final int RETR = 5;
037    /** Delete message(s). */
038    public static final int DELE = 6;
039    /** No operation. Used as a session keepalive. */
040    public static final int NOOP = 7;
041    /** Reset session. */
042    public static final int RSET = 8;
043    /** Authorization. */
044    public static final int APOP = 9;
045    /** Retrieve top number lines from message. */
046    public static final int TOP = 10;
047    /** List unique message identifier(s). */
048    public static final int UIDL = 11;
049    /**
050     * The capabilities command.
051     *
052     * @since 3.0
053     */
054    public static final int CAPA = 12;
055    /**
056     * Authentication
057     *
058     * @since 3.0
059     */
060    public static final int AUTH = 13;
061
062    private static final int NEXT = AUTH + 1; // update as necessary when adding new entries
063
064    static final String[] commands = { "USER", "PASS", "QUIT", "STAT", "LIST", "RETR", "DELE", "NOOP", "RSET", "APOP", "TOP", "UIDL", "CAPA", "AUTH", };
065
066    static {
067        if (commands.length != NEXT) {
068            throw new IllegalStateException("Error in array definition");
069        }
070    }
071
072    /**
073     * Get the POP3 protocol string command corresponding to a command code.
074     *
075     * @param command the command code
076     *
077     * @return The POP3 protocol string command corresponding to a command code.
078     */
079    public static String getCommand(final int command) {
080        return commands[command];
081    }
082
083    /** Cannot be instantiated. */
084    private POP3Command() {
085    }
086}