View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.net.pop3;
19  
20  /**
21   * POP3Command stores POP3 command code constants.
22   */
23  
24  public final class POP3Command {
25  
26      /** Send user name. */
27      public static final int USER = 0;
28  
29      /** Send password. */
30      public static final int PASS = 1;
31  
32      /** Quit session. */
33      public static final int QUIT = 2;
34  
35      /** Gets status. */
36      public static final int STAT = 3;
37  
38      /** List message(s). */
39      public static final int LIST = 4;
40  
41      /** Retrieve message(s). */
42      public static final int RETR = 5;
43  
44      /** Delete message(s). */
45      public static final int DELE = 6;
46  
47      /** No operation. Used as a session keepalive. */
48      public static final int NOOP = 7;
49  
50      /** Reset session. */
51      public static final int RSET = 8;
52  
53      /** Authorization. */
54      public static final int APOP = 9;
55  
56      /** Retrieve top number lines from message. */
57      public static final int TOP = 10;
58  
59      /** List unique message identifier(s). */
60      public static final int UIDL = 11;
61  
62      /**
63       * The capabilities command.
64       *
65       * @since 3.0
66       */
67      public static final int CAPA = 12;
68  
69      /**
70       * Authentication
71       *
72       * @since 3.0
73       */
74      public static final int AUTH = 13;
75  
76      private static final int NEXT = AUTH + 1; // update as necessary when adding new entries
77  
78      static final String[] commands = { "USER", "PASS", "QUIT", "STAT", "LIST", "RETR", "DELE", "NOOP", "RSET", "APOP", "TOP", "UIDL", "CAPA", "AUTH", };
79  
80      static {
81          if (commands.length != NEXT) {
82              throw new IllegalStateException("Error in array definition");
83          }
84      }
85  
86      /**
87       * Gets the POP3 protocol string command corresponding to a command code.
88       *
89       * @param command the command code
90       * @return The POP3 protocol string command corresponding to a command code.
91       */
92      public static String getCommand(final int command) {
93          return commands[command];
94      }
95  
96      /** Cannot be instantiated. */
97      private POP3Command() {
98      }
99  }