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 *
024 */
025
026public final class POP3Command
027{
028    /** Send user name. */
029    public static final int USER = 0;
030    /** Send password. */
031    public static final int PASS = 1;
032    /** Quit session. */
033    public static final int QUIT = 2;
034    /** Get status. */
035    public static final int STAT = 3;
036    /** List message(s). */
037    public static final int LIST = 4;
038    /** Retrieve message(s). */
039    public static final int RETR = 5;
040    /** Delete message(s). */
041    public static final int DELE = 6;
042    /** No operation.  Used as a session keepalive. */
043    public static final int NOOP = 7;
044    /** Reset session. */
045    public static final int RSET = 8;
046    /** Authorization. */
047    public static final int APOP = 9;
048    /** Retrieve top number lines from message. */
049    public static final int TOP = 10;
050    /** List unique message identifier(s). */
051    public static final int UIDL = 11;
052    /**
053     * The capabilities command.
054     * @since 3.0
055     */
056    public static final int CAPA = 12;
057    /**
058     * Authentication
059     * @since 3.0
060     */
061    public static final int AUTH = 13;
062
063    private static final int NEXT = AUTH + 1; // update as necessary when adding new entries
064
065    static final String[] commands = {
066                                          "USER", "PASS", "QUIT", "STAT", "LIST", "RETR", "DELE", "NOOP", "RSET",
067                                          "APOP", "TOP", "UIDL", "CAPA", "AUTH",
068                                      };
069
070    static {
071        if (commands.length != NEXT) {
072            throw new RuntimeException("Error in array definition");
073        }
074    }
075
076    // Cannot be instantiated.
077    private POP3Command()
078    {}
079
080    /**
081     * Get the POP3 protocol string command corresponding to a command code.
082     * @param command the command code
083     *
084     * @return The POP3 protocol string command corresponding to a command code.
085     */
086    public static String getCommand(final int command)
087    {
088        return commands[command];
089    }
090}