    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.pop3;
    019
    020/**
    021 * POP3Command stores POP3 command code constants.
    022 */
    023
    024public final class POP3Command {
    025
    026    /** Send user name. */
    027    public static final int USER = 0;
    028
    029    /** Send password. */
    030    public static final int PASS = 1;
    031
    032    /** Quit session. */
    033    public static final int QUIT = 2;
    034
    035    /** Gets status. */
    036    public static final int STAT = 3;
    037
    038    /** List message(s). */
    039    public static final int LIST = 4;
    040
    041    /** Retrieve message(s). */
    042    public static final int RETR = 5;
    043
    044    /** Delete message(s). */
    045    public static final int DELE = 6;
    046
    047    /** No operation. Used as a session keepalive. */
    048    public static final int NOOP = 7;
    049
    050    /** Reset session. */
    051    public static final int RSET = 8;
    052
    053    /** Authorization. */
    054    public static final int APOP = 9;
    055
    056    /** Retrieve top number lines from message. */
    057    public static final int TOP = 10;
    058
    059    /** List unique message identifier(s). */
    060    public static final int UIDL = 11;
    061
    062    /**
    063     * The capabilities command.
    064     *
    065     * @since 3.0
    066     */
    067    public static final int CAPA = 12;
    068
    069    /**
    070     * Authentication
    071     *
    072     * @since 3.0
    073     */
    074    public static final int AUTH = 13;
    075
    076    private static final int NEXT = AUTH + 1; // update as necessary when adding new entries
    077
    078    static final String[] commands = { "USER", "PASS", "QUIT", "STAT", "LIST", "RETR", "DELE", "NOOP", "RSET", "APOP", "TOP", "UIDL", "CAPA", "AUTH", };
    079
    080    static {
    081        if (commands.length != NEXT) {
    082            throw new IllegalStateException("Error in array definition");
    083        }
    084    }
    085
    086    /**
    087     * Gets the POP3 protocol string command corresponding to a command code.
    088     *
    089     * @param command the command code
    090     * @return The POP3 protocol string command corresponding to a command code.
    091     */
    092    public static String getCommand(final int command) {
    093        return commands[command];
    094    }
    095
    096    /** Cannot be instantiated. */
    097    private POP3Command() {
    098    }
    099}